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Sample records for radon thoron isotopic

  1. Measurement of Radon, Thoron, Isotopic Uranium and Thorium to Determine Occupational and Environmental Exposure and Risk at Fernald Feed Material Production Center

    International Nuclear Information System (INIS)

    Harley, Naomi H.

    2004-01-01

    To develop a new and novel area and personal radon/thoron detector for both radon isotopes to better measure the exposure to low airborne concentrations of these gases at Fernald. These measurements are to be used to determine atmospheric dispersion and exposure to radon and thoron prior to and during retrieval and removal of the 4000 Ci of radium in the two silos at Fernald

  2. Environmental radon and thoron monitor

    International Nuclear Information System (INIS)

    Thomas, J.W.

    1977-01-01

    A large two-filter type monitor (ERM-3) has been developed for measuring environmental levels of radon and thoron to within several picocuries per cubic meter. The inlet filters of the monitor remove daughter activity from the entering air stream but permit radon and thoron to pass. Daughter activity formed in the 0.9 m 3 decay chamber is collected by the fixed exit filter. The alpha activity of the filter is detected with a zinc sulfide scintillator and a 12 cm phototube, counted with an automatic timer and scaler, and is printed out on a teletypewriter for predetermined counting intervals. The teletypewriter also punches a tape to provide computer-compatible readout

  3. Thoron and radon measurements in houses

    International Nuclear Information System (INIS)

    Gauthier, C.

    1980-01-01

    Studies were made to determine what effect thoron daughters have on radon working level measurements in occupied houses at Elliot Lake. The decay of radon daughters is faster than that of thoron daughters. Six hours after sampling radon daughters are no longer present on the filter, and essentially all alpha activity is due to thoron C in transient equilibrium with thoron B. The concentrations can be extrapolated back to the time of the Kuznetz count, and the WL overestimation due to the presence of thoron daughters calculated. It was found using this method that in 70 percent of the samples the thoron contribution was no more than one mWL equivalent, less than the statistical error in the estimation of working levels. Only in buildings with very low ventilation rates and large areas of exposed concrete may corrections for the presence of thoron be necessary

  4. Metrology of radon and thoron concentrations

    International Nuclear Information System (INIS)

    Durcik, M; Vicanova, M.

    1998-01-01

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

  5. Radon and radon daughter monitoring (including thoron daughter monitoring)

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  6. Exhalation of radon and thoron from ground surface

    International Nuclear Information System (INIS)

    Megumi, Kazuko

    1978-01-01

    When radon and thoron in the environment are considered, the exhalations of radon and thoron from the ground surface are important. The following matters are described: a method of measuring directly the quantities of radon and thoron exhaled from the ground surface, the respective quantities measured by the method in summer and winter, and the dependence of the exhalations upon soil particle sizes. In this direct method, to obtain the exhalation quantities, radon and thoron from the ground surface are adsorbed in granular active carbon, and the γ-ray spectra are measured. The method is capable of measuring radon and thoron simultaneously in direct and inexpensive manner. For continuous measurement, however, it needs further improvement. The measurements by the method revealed the difference between summer and winter, the effect of rainfall, the dependence on soil particle size and on soil moisture of radon and thoron exhalations. (J.P.N.)

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  8. Dosimetry of inhaled radon and thoron progeny

    International Nuclear Information System (INIS)

    James, A.C.

    1994-06-01

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

  9. 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)

  10. The passive radon-thoron discriminative dosimeter for practical use

    International Nuclear Information System (INIS)

    Doi, Masahiro; Kobayashi, Sadayoshi

    1994-01-01

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

  11. Measurement of radon and thoron progenies in Coimbatore

    International Nuclear Information System (INIS)

    Sivakumar, R.; Selvasekarapandian, S.; Mahendraprasad, M.; Meenakshisundaram, V.; Santhanam, R.; Raghunath, V.M.

    2001-01-01

    The radon and thoron daughter concentrations have been measured in different dwellings of Coimbatore city by grab sampling method and two count. It has been found that the radon daughter concentration varies from 0.5 to 10.5 mWL with mean value of 2.9 mWL and that of thoron progeny is from 0.7 to 16.3 mWL with mean value of 3.8 mWL. The average annual effective dose equivalent due to radon daughters is found to be 1.3 mSv and that of thoron progeny is 3.8 mSv. (author)

  12. Measurements of thoron and radon progeny concentrations in Beijing, China

    International Nuclear Information System (INIS)

    Zhang Lei; Liu Cuihong; Guo Qiuju

    2008-01-01

    It has been reported that thoron levels in China are above the world average and may therefore make a significant contribution to the natural background radiation dose. We therefore conducted a pilot study of concentrations of both thoron and radon progeny during the spring of 2006 in the Beijing area, China. A new type of portable 24 h integrating monitor with a CR-39 detector was used during the survey. Seventy dwellings and eight outdoor sites were measured during the survey. For country houses built of red bricks and slurry, the average equilibrium equivalent concentrations (EEC) of thoron and radon were 1.02 ± 0.48 and 16.41 ± 9.02 Bq m -3 , respectively, whereas for city dwellings built of cement blocks and floor slabs, the results were 0.48 ± 0.47 and 11.50 ± 6.99 Bq m -3 for thoron and radon, respectively. For outdoor air, concentrations of thoron and radon progeny were 0.29 ± 0.28 and 7.05 ± 2.68 Bq m -3 , respectively. Radiation exposures from thoron and radon progeny were also evaluated; the ratio of dose contribution from thoron progeny to that of radon progeny was evaluated to be 28% and 17% in country houses and city dwellings, respectively. (note)

  13. Mitigation of radon and thoron decay products by filtration

    International Nuclear Information System (INIS)

    Wang Jin; Meisenberg, Oliver; Chen Yongheng; Karg, Erwin; Tschiersch, Jochen

    2011-01-01

    Inhalation of indoor radon ( 222 Rn) and thoron ( 220 Rn) decay products is the most important source of exposure to ionizing radiation for the human respiratory tract. Decreasing ventilation rates due to energy saving reasons in new buildings suggest additional active mitigation techniques to reduce the exposure in homes with high radon and thoron concentrations but poor ventilation. Filtration techniques with HEPA filters and simple surgical mask material have been tested for their potential to reduce the indoor exposure in terms of the total effective dose for mixed radon and thoron indoor atmospheres. The tests were performed inside an experimental room providing stable conditions. Filtration (at filtration rates of 0.2 h -1 and larger) removes attached radon and thoron decay products effectively but indoor aerosol as well. Therefore the concentration of unattached decay products (which have a higher dose coefficient) may increase. The decrease of the attached decay product concentrations could be theoretically described by a slowly decreasing exponential process. For attached radon decay products, it exhibited a faster but weaker removal process compared to attached thoron decay products (- 70% for attached radon decay products and - 80% for attached thoron decay products at a filtration rate of 0.5 h -1 with an HEPA filter). The concentration of unattached thoron decay products increased distinctly during the filtration process (+ 300%) while that of unattached radon decay products rose only slightly though at a much higher level (+ 17%). In the theoretical description these observed differences could be attributed to the different half-lives of the nuclides. Considering both effects, reduced attached and increased unattached decay product concentrations, filtration could significantly decrease the total effective dose from thoron whereas the overall effect on radon dose is small. A permanent filtration is recommended because of the slow decrease of the

  14. Experimental study of radon and thoron diffusion through barriers

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  15. An overview of radon and thoron research in India

    International Nuclear Information System (INIS)

    Ramola, R.C.

    2015-01-01

    An overview of radon and thoron research in India is presented in this paper. World Health Organisation along with ICRP and UNSCEAR has identified radon as the second cause of lung cancer after smoking. Apart from the health effects of radon, it has also played a role in many scientific areas such as radiotherapy, meteorology and geophysics. Radon has been studied in India by various research groups for its environmental and geophysical applications. The findings of various research groups show that there is a basis to enhance radon and thoron research and practice in the country. To be more efficient, these activities need collaboration with various authorities of the country and with international teams working in the field. Major achievements in radon and thoron research in the country accomplished in the past three decades are highlighted here. (author)

  16. Experimental study of radon and thoron diffusion through barriers

    International Nuclear Information System (INIS)

    Durcik, M.; Havlik, F.

    1995-01-01

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

  17. Soil gas radon and thoron measurements in some Venezuelan oilfields

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  18. Radon and thoron levels, their spatial and seasonal variations in adobe dwellings - a case study at the great Hungarian plain.

    Science.gov (United States)

    Szabó, Zsuzsanna; Jordan, Gyozo; Szabó, Csaba; Horváth, Ákos; Holm, Óskar; Kocsy, Gábor; Csige, István; Szabó, Péter; Homoki, Zsolt

    2014-06-01

    Radon and thoron isotopes are responsible for approximately half of the average annual effective dose to humans. Although the half-life of thoron is short, it can potentially enter indoor air from adobe walls. Adobe was a traditional construction material in the Great Hungarian Plain. Its major raw materials are the alluvial sediments of the area. Here, seasonal radon and thoron activity concentrations were measured in 53 adobe dwellings in 7 settlements by pairs of etched track detectors. The results show that the annual average radon and thoron activity concentrations are elevated in these dwellings and that the proportions with values higher than 300 Bq m(-3) are 14-17 and 29-32% for radon and thoron, respectively. The calculated radon inhalation dose is significantly higher than the world average value, exceeding 10 mSv y(-1) in 7% of the dwellings of this study. Thoron also can be a significant contributor to the inhalation dose with about 30% in the total inhalation dose. The changes of weather conditions seem to be more relevant in the variation of measurement results than the differences in the local sedimentary geology. Still, the highest values were detected on clay. Through the year, radon follows the average temperature changes and is affected by the ventilation, whereas thoron rather seems to follow the amount of precipitation.

  19. Radon and thoron measurements at special underground circumstances

    International Nuclear Information System (INIS)

    Kovacs, Tibor; Somlai, Janos; Szeiler, Gabor; Nemeth, Csaba; Tokonami, Shinji; Takahashi, Hiroyuki

    2008-01-01

    In this study a comparative integrating radon ( 222 Rn) and thoron ( 220 Rn) survey executed at underground workplaces are discussed. Two types of solid state nuclear track detectors (Radopot and Raduet) were applied for survey at four sites: a manganese mine, a bauxite mine, a tourist cave and a hospital cave. Several numbers of detecting points were chosen at each site and 1-1 Raduet and Radopot detector were placed at each point. Both detector types contains two polycarbonate (CR-39) foils in different holders in order to determinate the radon as well as the thoron levels. The detectors were changed in 30-60 days periods (approximately monthly) and the survey continued for a year. This study had two aims: 1) To gain information about the radon and thoron concentrations at the chosen places including the seasonal variations; 2) To compare the performance of the two types of detectors and check their response in the special circumstances indicates by these underground places. Concerning the first point the radon concentrations were found to be as the expected ones at the given underground places and were similar to our former measurements. In the case of thoron the results are very variable and significant part of the detectors provides no data or unrealistic data. Concerning the second point there was only a little difference (<10%) between the radon results provided by the two types of detectors. In the case of thoron the two detector types showed high inconsistency. The study suggests that both types of detectors are fit for the integrating radon measurement at these special circumstances but it cannot be stated the same for the thoron measurement. The reason of the unreliability of the thoron measurement could be the high humidity (especially in the caves), the high aerosol concentration (especially in the mines) and the air change rate variation. To find the reasons needs further study. (author)

  20. Indoor thoron and radon progeny measurements

    International Nuclear Information System (INIS)

    Tu, K.W.; George, A.C.; Lowder, W.M.; Gogolak, C.V.

    1992-01-01

    Measurements of indoor thoron ( 220 Rn) and radon ( 222 Rn) progeny activities were conducted in 40 homes and six public buildings in five states. A commercial alpha spectrometer system and four portable alpha integrating sampling monitors using diffused junction silicon detectors were used for sampling and recording of radionuclide data in particular the potential alpha energy concentrations (PAEC). The data were analysed for the ratios of PAEC- 220 Rn to PAEC- 222 Rn, and the correlations between the two quantities, and their estimated annual effective dose equivalent (AEDE). The results show that the PAEC ratios were 0.09, 0.6, 0.55, and 0.47, respectively, for all homes with the PAEC- 222 Rn > 400, between 100 and 400, -3 , and the total of all homes tested; the AEDE ratios were 0.03, 0.21, 0.19 and 0.16, respectively. No strong correlations were found between PAEC- 220 Rn and PAEC- 222 Rn, and between basement and ground floor data for PAEC- 220 Rn, but the PAEC- 222 Rn data showed a strong correlation between the basement and the ground floor values. Simultaneous measurements of PAEC- 220 Rn and PAEC- 222 Rn on the ground floor and in the basement of each of the 23 single-family houses tested suggests that 220 Rn entry from building materials may be as significant as from the underlying soil. (author)

  1. Radon and thoron progeny measurements using a portable radon sniffer

    International Nuclear Information System (INIS)

    Efendi, Z.; Jennings, P.

    1993-01-01

    A flexible version of the two-count method has been developed for use in rapid, inexpensive measurements of radon and thoron progeny working levels in residential and industrial premises in the Perth Metropolitan Area. The Method is adapted for use with a simple radon sniffer based on a low speed pump and an alpha counter. The flexibility of the method derives from the software, where some freedom is permitted in the selection of sampling times and post sampling analysis of the filters. This method has been tested on a variety of radioactive materials and it gives consistent, reliable results over a wide range of working levels. The results of a survey of Rn(222) and Rn(220) progeny levels in dwellings within the Perth Metropolitan Area are reported. This study shows that the mean concentration of indoor Rn(222) progeny was 4.7 mWL (17.4 Bq m -3 EEC) up to 23.3 mWL (86.4 Bq m -3 EEC). The mean thoron progeny concentration was 8.2 mWL (2.25 Bq m -3 EEC) with a range from 1 mWL (0.27 Bq m -3 EEC) to 64.5 mWL (17.74 Bq m -3 EEC). Using conversion factors of 0.061 mSv Bq -1 m -3 for Rn(222) progeny and 0.29 mSv Bq -1 m -3 for Rn(220) progeny respectively (UNSCEAR, 1982), it is estimated the average annual effective dose equivalent is 1.1 mSv for Rn(2220 and 0.6 mSv for Rn(220) respectively. 22 refs., 4 tabs., 1 fig

  2. Automated radon-thoron monitoring for earthquake prediction research

    International Nuclear Information System (INIS)

    Shapiro, M.H.; Melvin, J.D.; Copping, N.A.; Tombrello, T.A.; Whitcomb, J.H.

    1980-01-01

    This paper describes an automated instrument for earthquake prediction research which monitors the emission of radon ( 222 Rn) and thoron ( 220 Rn) from rock. The instrument uses aerosol filtration techniques and beta counting to determine radon and thoron levels. Data from the first year of operation of a field prototype suggest an annual cycle in the radon level at the site which is related to thermoelastic strains in the crust. Two anomalous increases in the radon level of short duration have been observed during the first year of operation. One anomaly appears to have been a precursor for a nearby earthquake (2.8 magnitude, Richter scale), and the other may have been associated with changing hydrological conditions resulting from heavy rainfall

  3. Improved automated analysis of radon (222Rn) and thoron (220Rn) in natural waters.

    Science.gov (United States)

    Dimova, Natasha; Burnett, William C; Lane-Smith, Derek

    2009-11-15

    Natural radon ((222)Rn) and thoron ((220)Rn) can be used as tracers of various chemical and physical processes in the environment. We present here results from an extended series of laboratory experiments intended to improve the automated analysis of (222)Rn and (220)Rn in water using a modified RAD AQUA (Durridge Inc.) system. Previous experience with similar equipment showed that it takes about 30-40 min for the system to equilibrate to radon-in-water concentration increases and even longer for the response to return to baseline after a sharp spike. While the original water/gas exchanger setup was built only for radon-in-water measurement, our goal here is to provide an automated system capable of high resolution and good sensitivity for both radon- and thoron-in-water detections. We found that faster water flow rates substantially improved the response for both isotopes while thoron is detected most efficiently at airflow rates of 3 L/min. Our results show that the optimum conditions for fastest response and sensitivity for both isotopes are at water flow rates up to 17 L/min and an airflow rate of 3 L/min through the detector. Applications for such measurements include prospecting for naturally occurring radioactive material (NORM) in pipelines and locating points of groundwater/surface water interaction.

  4. Dosimetry, measurement and properties of radon daughters and thoron daughters

    International Nuclear Information System (INIS)

    Phillips, C.R.

    1982-03-01

    Various properties of radon and thoron daughter products are examined. Dosimeter methods and instrumentation (TLD and personal alpha dosimeters) are investigated as to performance under varying conditions such as humidity and pure or mixed atmospheric conditions. Optimized counting schemes are determined for the daughters of radon and thoron. An optimized counting scheme was experimentally examined under mine conditions. The optimization procedure takes into account the uncertainties associated with concentration, flow rate and radioactive decay. Measurements were made in two uranium mines at Elliot Lake, Ontario of the charged and unattached fractions of radon daughters in the mines. The physicochemical state of 218 Po in air was determined by measurement of rate of neutralization, diffusion coefficient and fraction born charge. Careful control of experimental conditions made it possible to obtain more precise and detailed quantitative data than previously possible

  5. Interference from radon-thoron daughters in plutonium channel of a continuous plutonium-in-air monitor

    International Nuclear Information System (INIS)

    Pendharkar, K.A.; Krishnamony, S.

    1983-01-01

    This paper summarises the results of a study conducted to define the extent of interference from the daughter products of radon/thoron to the plutonium channel of a continuous plutonium-in-air monitor. The effect on the detection limits of the instrument due to chemical form (transportable or non-transportable) and isotopic composition of plutonium aerosol are briefly discussed. (author)

  6. Study on radon and thoron levels in different types of granitic work industries around Tumkur city

    International Nuclear Information System (INIS)

    Nagabhushan, S.R.; Ujjinappa; Srilatha; Sannappa, J.

    2013-01-01

    Radon, Thoron and its progeny monitoring has become a global phenomenon due to its health hazards on human being. The concentration of radon, thoron and their progeny levels have been measured in different types of Granite and brick work industries around Tumkur city by using LR-115 type II Solid State Nuclear Track Detectors (SSNTDs) have been used for the measurement of these gases. The higher concentration of radon, thoron and their progeny were observed in the dwellings near brick industries compared to Granite cutting and polishing industries. The inhalation dose due to Radon, Thoron and their progeny to the workers and public living near these industries have been estimated. (author)

  7. Development of an electronic monitor for the determination of individual radon and thoron exposure

    Energy Technology Data Exchange (ETDEWEB)

    Irlinger, Josef

    2015-06-11

    The carcinogenic effect of the radio isotope {sup 222}Rn of the noble gas radon and its progeny, as well as its residential distribution, are well studied. In contrast, the knowledge about the effects and average dwelling concentration levels of its radio isotope {sup 220}Rn (thoron) is still limited. Generally, this isotope has been assumed to be a negligible contributor to the effective annual dose. However, only recently it has been pointed out in several international studies, that the dose due to thoron exceeds the one from {sup 222}Rn under certain conditions. Additionally, radon monitors may show a considerable sensitivity towards thoron which was also not accounted for in general. Therefore a reliable, inexpensive exposimeter, which allows to distinguish between decays of either radon and thoron, is required to conduct further studies. The scope of this thesis was to develop an electronic radon/thoron exposimeter which features small size, low weight and minimal power consumption. The design is based on the diffusion chamber principle and employs state-of-the-art alpha particle spectroscopy to measure activity concentrations. The device was optimized via inlet layout and filter selection for high thoron diffusion. Calibration measurements showed a similar sensitivity of the monitor towards radon and thoron, with a calibration factor of cf{sup {sub 2}{sub 2}{sub 2Rn}} = 16.2 ± 0.9 Bq m{sup -3}/cph and cf{sup {sub 2}{sub 2}{sub 0Rn}} = 14.4 ± 0.8 Bq m{sup -3}/cph, respectively. Thus, the radon sensitivity of the device was enhanced by a factor two compared to a previous prototype. The evaluation method developed in this work, in accordance with ISO 11665 standards, was validated by intercomparison measurements. The detection limits for radon and thoron were determined to be C{sup {sub 2}{sub 2}{sub 2Rn}} = 44.0 Bq m{sup -3} and C{sup {sub 2}{sub 2}{sub 0Rn}} = 40.0 Bq m{sup -3}, respectively, in case of a low radon environment, a one-hour measurement

  8. Development of an electronic monitor for the determination of individual radon and thoron exposure

    International Nuclear Information System (INIS)

    Irlinger, Josef

    2015-01-01

    The carcinogenic effect of the radio isotope 222 Rn of the noble gas radon and its progeny, as well as its residential distribution, are well studied. In contrast, the knowledge about the effects and average dwelling concentration levels of its radio isotope 220 Rn (thoron) is still limited. Generally, this isotope has been assumed to be a negligible contributor to the effective annual dose. However, only recently it has been pointed out in several international studies, that the dose due to thoron exceeds the one from 222 Rn under certain conditions. Additionally, radon monitors may show a considerable sensitivity towards thoron which was also not accounted for in general. Therefore a reliable, inexpensive exposimeter, which allows to distinguish between decays of either radon and thoron, is required to conduct further studies. The scope of this thesis was to develop an electronic radon/thoron exposimeter which features small size, low weight and minimal power consumption. The design is based on the diffusion chamber principle and employs state-of-the-art alpha particle spectroscopy to measure activity concentrations. The device was optimized via inlet layout and filter selection for high thoron diffusion. Calibration measurements showed a similar sensitivity of the monitor towards radon and thoron, with a calibration factor of cf 222 Rn = 16.2 ± 0.9 Bq m -3 /cph and cf 220 Rn = 14.4 ± 0.8 Bq m -3 /cph, respectively. Thus, the radon sensitivity of the device was enhanced by a factor two compared to a previous prototype. The evaluation method developed in this work, in accordance with ISO 11665 standards, was validated by intercomparison measurements. The detection limits for radon and thoron were determined to be C 2 22 Rn = 44.0 Bq m -3 and C 2 20 Rn = 40.0 Bq m -3 , respectively, in case of a low radon environment, a one-hour measurement interval, and a background count rate of zero. In contrast, in mixed radon/thoron concentrations where the 212 Po peak must

  9. Study on radon and thoron progeny levels in Gudalore in South India

    International Nuclear Information System (INIS)

    Selvasekarapandian, S.; Sivakumar, R.; Mugunthamanikandan, N.; Meenakshisundaram, V.; Santhanam, R.

    2000-01-01

    One of the important route of radiation exposure to man is through inhalation of air containing radioisotopes. A major contribution to inhalation dose comes from radon, thoron and its progenies. The indoor radon and thoron progeny levels are determined by two count method. In this method the radon and thoron progenies are collected on a glass fiber filter paper using volume air sampler (Staplex) and counted for alpha activity in ZnS (Ag) alpha counting system. It is observed that thoron working level is higher than the radon working level in all houses except few houses with stone walls and mosaic floor. Behavior of indoor radon and thoron working levels for different seasons at different houses are determined and discussed in detail. Radon and thoron working levels are measured high in winter, autumn, and low in summer and rainy seasons. Among all seasons highest value is measured in winter and low in summer and rainy seasons. Radon progeny working level varies from 1.659 to 6.675 mWL, whereas thoron progeny working level varies from 1.670 to 12.671 mWL. The geometric mean values of radon and thoron progeny concentration in the present study are 2.836 and 4.133 mWL. The high thoron progeny level observed in this is attributed to the high thorium content observed in soils of this area. (author)

  10. Diffusion coefficients of decay products of radon and thoron

    International Nuclear Information System (INIS)

    Raghunath, B.; Kotrappa, P.

    1979-01-01

    The diffusion coefficients of the decay products of radon and thoron have relevance in the evaluation of inhalation hazards in uranium and thorium processing industries. A recently developed diffusion sampler, based on Mercer's theory of diffusional deposition between the concentric circular plates, has been used for determining the diffusion coefficients of the unattached decay products of radon and thoron (RaA, RaB, RaC and ThB). Experiments were conducted at different ventilation rates (6 and 60 changes/hr) at different relative humidities (10 and 90%) and both in air and argon atmospheres. Diffusion coefficients were found to increase with increasing ventilation rates and were found to decrease at higher relative humidities, the effect being more marked at lower ventilation rates. Both of these effects were less pronounced in argon than in air. Results are discussed in light of the known properties of these decay products. (author)

  11. A new passive radon-thoron discriminative measurement system

    International Nuclear Information System (INIS)

    Sciocchetti, G.; Sciocchetti, A.; Giovannoli, P.; DeFelice, P.; Cardellini, F.; Cotellessa, G.; Pagliari, M.

    2010-01-01

    A new passive radon-thoron discriminative measurement system has been developed for monitoring radon and thoron individually. It consists of a 'couple' of passive integrating devices with a CR39 nuclear track detector (NTD). The experimental prototype is based on the application of a new concept of NTD instrument developed at ENEA, named Alpha-PREM, acronym of piston radon exposure meter, which allows controlling the detector exposure with a patented sampling technique (Int. Eu. Pat. and US Pat.). The 'twin diffusion chambers system' was based on two A-PREM devices consisting of the standard device, named NTD-Rn, and a modified version, named NTD-Rn/Tn, which was set up to improve thoron sampling efficiency of the diffusion chamber, without changing the geometry and the start/stop function of the NTD-Rn device. Coupling devices fitted on each device allowed getting a system, which works as a double-chamber structure when deployed at the monitoring position. In this paper both technical and physical aspects are considered. (authors)

  12. A new passive radon-thoron discriminative measurement system.

    Science.gov (United States)

    Sciocchetti, G; Sciocchetti, A; Giovannoli, P; DeFelice, P; Cardellini, F; Cotellessa, G; Pagliari, M

    2010-10-01

    A new passive radon-thoron discriminative measurement system has been developed for monitoring radon and thoron individually. It consists of a 'couple' of passive integrating devices with a CR39 nuclear track detector (NTD). The experimental prototype is based on the application of a new concept of NTD instrument developed at ENEA, named Alpha-PREM, acronym of piston radon exposure meter, which allows controlling the detector exposure with a patented sampling technique (Int. Eu. Pat. and US Pat.). The 'twin diffusion chambers system' was based on two A-PREM devices consisting of the standard device, named NTD-Rn, and a modified version, named NTD-Rn/Tn, which was set up to improve thoron sampling efficiency of the diffusion chamber, without changing the geometry and the start/stop function of the NTD-Rn device. Coupling devices fitted on each device allowed getting a system, which works as a double-chamber structure when deployed at the monitoring position. In this paper both technical and physical aspects are considered.

  13. Measurement of outdoor radioactivities of radon and thoron by the passive radon-thoron monitor of cup type with cellulose nitrate film

    International Nuclear Information System (INIS)

    Ogawa, Y.; Kimura, Y.; Iida, T.; Yamasaki, K.; Tsujimoto, T.

    1993-01-01

    In order to get information as to effective dose of radon and thoron for the public, we investigated the dosimetry of the average outdoor concentrations of radon and thoron by the cup type radon/thoron monitor using cellulose nitrate film. To overcome the disadvantages of cup monitors which are the relatively low sensitivity and the relatively high detection limit, the present dosimetry is based on the usage of several pairs of cup monitors and the statistical treatments (significant test). Because the detection limit could be lowered using the present dosimetry, we could measure the outdoor concentration levels more precisely. (1 tab.)

  14. 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.

  15. Exposures to radon and thoron and their decay products. Annex D

    International Nuclear Information System (INIS)

    1982-01-01

    The purpose of this Annex, which has over 400 references, is to provide information about the levels and doses of radon and thoron and their decay products, and about physical parameters influencing and causing these levels and doses. The detrimental effects of radon and thoron daughters are not dealt with in this Annex.

  16. Radon-thoron exposures in high background radiation areas: a review

    International Nuclear Information System (INIS)

    Nambi, K.S.

    1994-01-01

    The radon-thoron measurements reported in literature for the high background radiation areas (HBRAs) of the world are summarised here. The most important areas covered are the Radon Spas and the thorium bearing monazite deposits. Special mention is made of the ongoing programmes of radon-thoron survey in the monazite beach areas of India; preliminary measurements indicate significant levels of thoron exposures. The diurnal and seasonal variations are quite wide underscoring the importance of carrying out integrated measurements for meaningful assessments of population exposures. Radon-thoron inhalation dose rates upto 30 mSv/y have been measured in lran as well as India. It has been generally observed that the cumulative population doses due to radon-thoron inhalation are as high as those due to the external exposures in these HBRAs. (author). 7 refs., 2 tabs., 3 figs

  17. Correlation of radon and thoron concentrations with natural radioactivity of soil in Zonguldak, Turkey

    Science.gov (United States)

    Koray, Abdullah; Akkaya, Gizem; Kahraman, Ayşegül

    2017-02-01

    Radon and thoron gases are produced by the decay of the radioactive elements those are radium and thorium in the soil. In this study, the correlations between soil radon and thoron concentration with their parent nuclide (226Ra and 232Th) concentrations in collected soil samples from the same locations were evaluated. The result of the measurement shows that the distribution of radon and thoron in soil showed the same tendency as 226Ra and 232Th distribution. It was found a weak correlation between the radon and the 226Ra concentration (R =0.57), and between the thoron and the 232Th concentration (R=0.64). No strong correlation was observed between soil-gas radon and thoron concentration (R = 0.29).

  18. Seasonal variation in concentration of radon and thoron at non-uranium mines in China

    International Nuclear Information System (INIS)

    Cui Hongxing; Wu Yunyun; Zhang Qingzhao; Shang Bing

    2009-01-01

    Objective: To study the seasonal variation in concentrations of radon and thoron in non-uranium mine. Methods: Eight kinds of mineral types from 9 non-uranium mines were selected, including copper, gold, aluminium, manganese, antimonium, tungsten, copper-nickel and coal mines in 6 provinces, such as Yunnan, Shandong, Xinjiang, Heilongjiang, Hunan and Guizhou. LD-P R-T discriminative detectors were used to measure radon and thoron concentrations in underground mines during four seasons in one year. Results: Radon concentrations in underground mines showed a significantly seasonal variation. Radon concentration ranged from 35.5 to 4841 Bq/m 3 in summer, and the average value in four mines exceeded 1000 Bq/m 3 of the control limit for workplace (GB 18871-2002) . In winter, radon concentration ranged from 5 to 1917 Bq/m 3 , only one of them exceeded the control limit. The ratio of radon from summer to winter ranged from 2 to 12. Ventilation was one of the main factors which influenced the seasonal variation of radon. While the thoron concentration in underground mines showed a tendency that it was higher in summer and lower in winter. It was difficult to attain representative values for thoron, due to the influence of location of detectors. The seasonal variation of thoron should be further studied. Conclusions: Seasonal variation for radon and thoron should be taken into account to estimate the effective dose to miners. The values of radon concentration during the short term should be corrected. (authors)

  19. Study on radon and thoron levels in different types of granitic work industries around Tumkur city

    International Nuclear Information System (INIS)

    Nagabhushan, S.R.; Ningappa, C.; Srilatha; Shekar, Usha; Sannappa, J.

    2011-01-01

    Radon is a naturally occurring radioactive noble gas generated by the decay of uranium and thorium bearing minerals in rocks, soils and building materials. Radon and decay products are the major contributors to human exposure from natural radiation sources. Epidemiological evidence indicates that indoor radon and thoron were responsible for a substantial number of lung cancer in publics. UNSCEAR reported recently indicates that there is a remarkable coherence between the risk estimates developed from epidemiological studies from miners and residential case-control radon studies. Hence to select the study area for the estimation of dose due to radon and thoron to the publics and workers, concentration of radon, thoron and their progeny were measured by using SSNTD. Since, activity concentration in granite more, higher concentrations of radon and thoron have been observed in the dwellings near to granite industry and lesser concentration of radon and thoron have been observed in the dwellings near brick industries of Tumkur city. From the study, the concentration of radon and thoron varied from 31 to 70.4 Bq.m 3 and 11.6 to 46.3 Bq.m 3 , respectively. Corresponding progeny level varied from 0.11 to 2.5 mWL and 1.1 to 3.4 mWL, respectively. (author)

  20. Methodology and monitoring of radon, thoron and their daughters

    International Nuclear Information System (INIS)

    Townsend, M.G.

    1984-02-01

    Methods are described for monitoring radon and thoron gases and their daughter products in occupational and non-occupational environments. Grab-sampling, continuous monitoring, integrated measurements and personal dosimetry are discussed. Errors in different measurement methods are compared. Calibration aspects of measurement techniques are described and procedures for interlaboratory calibration are suggested. An account of unattached fraction and plateout of radon daughters is included. Sampling strategies for occupational and non-occupational environments are discussed and a table of regulations and recommendations for monitoring radiation in countries of the OECD is provided. Radiation protection training requirements are identified. Where sufficient information and consensus of opinion exist, guidelines on apparatus, methods and procedures for monitoring are developed

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  2. Seasonal levels of radon and thoron in the dwellings along southern coastal Orissa, Eastern India

    International Nuclear Information System (INIS)

    Sulekha Rao, N.; Sengupta, D.

    2010-01-01

    Inhalation of radon ( 222 Rn) and thoron ( 220 Rn) are a major source of natural radiation exposure. Indoor radon-thoron study has been carried out in some dwellings of Ganjam district, southern coastal Orissa, India using LR-115 type II plastic track detectors. Seasonal variation of indoor radon and thoron shows high values in winter and low values in both summer and rainy. The inhalation dose lies in the range of 0-0.06 μSv h -1 and is not high from those found elsewhere in India.

  3. Seasonal levels of radon and thoron in the dwellings along southern coastal Orissa, Eastern India

    Energy Technology Data Exchange (ETDEWEB)

    Sulekha Rao, N [Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Sengupta, D. [Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)], E-mail: dsgg@gg.iitkgp.ernet.in

    2010-01-15

    Inhalation of radon ({sup 222}Rn) and thoron ({sup 220}Rn) are a major source of natural radiation exposure. Indoor radon-thoron study has been carried out in some dwellings of Ganjam district, southern coastal Orissa, India using LR-115 type II plastic track detectors. Seasonal variation of indoor radon and thoron shows high values in winter and low values in both summer and rainy. The inhalation dose lies in the range of 0-0.06 {mu}Sv h{sup -1} and is not high from those found elsewhere in India.

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

    International Nuclear Information System (INIS)

    Phillips, C.R.; Leung, H.

    1981-01-01

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

  5. Radon and thoron monitoring in the environment of Kumaun Himalayas: survey and outcomes

    International Nuclear Information System (INIS)

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

    2005-01-01

    Monitoring of radon, thoron and their daughter products was carried out in houses of Kumaun Himalaya, India using LR-115 plastic track detectors. The measurements were made in residential houses from June 1999 to May 2000 at a height of 2.5 m from ground level using a twin chamber radon dosimeter. The twin chamber radon dosimeter can record the values of radon, thoron and their decay products separately. Maximum and minimum indoor radon and thoron concentrations were evaluated and activity concentrations of radon and thoron daughters were estimated. The resulting dose rates due to radon, thoron and their decay products varied from 0.04 to 1.89 μSv/h. A detailed analysis of the distribution of radon, thoron and their decay products inside the house is also reported. The observed dose rates inside the houses of Kumaun Himalaya were found to be lower than the ICRP recommended value of 200 Bq/m 3 and thus are within safe limits

  6. The study of thoron and radon progeny concentrations in dwellings in Japan

    International Nuclear Information System (INIS)

    Guo, Q.; Shimo, M.; Ikebe, Y.

    1992-01-01

    Ths paper aims to make a comparison of different concentrations of thoron ( 220 Rn) progeny and radon ( 222 Rn) progeny in different kinds of dwellings. The potential alpha energy concentrations and the effective dose equivalent caused by thoron and radon progeny, respectively, have also been estimated. The measurements were carried out in 23 dwellings. The results indicate that thoron progeny concentrations indoors might be strongly affected by the type of building material used. Traditional Japanese buildings made with mud may have high thoron progeny concentrations of about 3.52 Bq.m -3 and a concentration ratio of thoron progeny to radon progeny of about 0.5, whereas in concrete dwellings thoron progeny concentrations are about 0.72 Bq.m -3 and the concentration ratio of thoron progeny to radon progeny is about 0.1. The annual effective dose equivalent of thoron progeny is 1.23 mSv in mud dwellings and 0.25 mSv in concrete dwellings. (author)

  7. Metrology and monitoring of radon, thoron and their daughter products

    International Nuclear Information System (INIS)

    1985-01-01

    The principles of measurement and monitoring are described as applied to radon- and thoron gases and their daughter products in occupational and non-occupational environments. Various methods of measurement, such as grab-sampling, continuous monitoring, integrated measurements and personal dosimetry are discussed. Uncertainties in different measurement methods are compared. An account of unattached fraction and plateout of radon daughters is included. General principles and guidelines for monitoring are presented for the purposes of practical radiation protection as well as research applications. Calibration aspects of measurement instruments are described and procedures for interlaboratory calibration are suggested. Sampling strategies for occupational and non-occupational environments are discussed and radiation protection training requirements are identified. Where sufficient information and consensus exist, guidelines on apparatus, methods and procedures for monitoring are provided. A summary of regulations in force or being developed and recommendations for monitoring radiation exposure to radon and its decay products in countries of the OECD is provided, together with cost estimates for national indoor radon surveys

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

    Directory of Open Access Journals (Sweden)

    V.S. Yakovleva

    2014-06-01

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

  9. Development of a brand-new radon-thoron discriminative detector

    International Nuclear Information System (INIS)

    Tokonami, S.; Hulber, E.

    2004-01-01

    A brand-new radon-thoron discriminative detector has been developed for the purposes of large-scope surveys. The configuration and features of this facility in comparison to our previous detector are described

  10. Optimization of the Timepix chip to measurement of radon, thoron and their progenies

    Czech Academy of Sciences Publication Activity Database

    Janik, M.; Ploc, Ondřej; Fiederle, M.; Proc, S.; Kavasi, N.

    2016-01-01

    Roč. 107, JAN (2016), s. 220-224 ISSN 0969-8043 Institutional support: RVO:61389005 Keywords : Radon * Thoron * Timepix * calibration Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.128, year: 2016

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  12. Analysis of atmospheric concentrations of radon and thoron using beta counting technique

    International Nuclear Information System (INIS)

    Islam, G.S.; Basunia, S.M.

    1995-05-01

    This paper presents a detailed theory and experimental procedure for measurement and analysis of mixed radon and thoron in the environment. The technique has been successfully applied to the study of seasonal variations of radon and thoron in Rajshahi atmosphere during the years 1989-1991. The maximum radon concentration in outdoor air was observed in the winter from December to January while the indoor radon concentration was found to be maximum during the monsoon months of July and August. The implication of results is briefly discussed in the paper. (author). 4 refs, 6 figs, 2 tabs

  13. 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

  14. Collaborative investigations on thoron and radon in some rural communities of Balkans

    International Nuclear Information System (INIS)

    Zunic, Z. S.; Celikovic, I.; Tokonami, S.; Ishikawa, T.; Ujic, P.; Onischenko, A.; Zhukovsky, M.; Milic, G.; Jakupi, B.; Cuknic, O.; Veselinovic, N.; Fujimoto, K.; Sahoo, S. K.; Yarmoshenko, I.

    2010-01-01

    This paper deals with the results of the first-field use in the Balkans, i.e. Serbia and Republic of Srpska (Bosnia and Herzegovina), of a passive polycarbonate Mark II type and poli-allyl-diglycol carbonate (Cr-39) alpha track detectors sensitive to thoron as well as to radon. Both types of solid state nuclear track detectors were designed and supplied by National Inst. of Radiological Sciences (NIRS), Chiba (Japan). The commercial names for these detectors which all have been field tested in Balkan rural communities are known as: UFO and RADUET passive discriminative radon/thoron detectors. No database of thoron and thoron progeny concentrations in dwellings in Serbia or Balkans region exist, and as a result, the level of exposure of the Serbian population to thoron and its progeny is unknown so far. (authors)

  15. Radon and thoron emanation from various marble materials: impact on the workers

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Amghar, A.

    2005-01-01

    Uranium ( 238 U) and thorium ( 232 Th) concentrations were measured inside different pulverized marble material samples by using a method based on determining detection efficiencies of the CR-39 and LR-115 II solid state nuclear track detectors for the emitted alpha particles. Radon ( 222 Rn) and thoron ( 220 Rn) alpha-activities per unit volume were evaluated inside and outside the marble samples studied. Radon emanation coefficient was determined for the considered marble samples. Alpha- and beta-activities per unit volume of air due to radon, thoron and their progenies were measured in the atmosphere of a marble factory. Equilibrium factors between radon and its progeny and thoron and its decay products were evaluated in the air of the studied marble factory. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of workers in the considered marble factory

  16. 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)

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

    International Nuclear Information System (INIS)

    Kazumasa Inoue; Masahiro Fukushi

    2013-01-01

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

  18. Radon-thoron levels and inhalation dose distribution patterns in India dwellings

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Eappen, K.P.; Nair, R.N.; Mayya, Y.S.; Sadasivan, S.

    2003-09-01

    A countrywide survey on radon and thoron levels has been carried out in Indian dwellings under a Coordinated Research Project sponsored by the Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE). Eight universities and a few research institutions from different parts of the country participated in this project. Under this project, radon and thoron levels were measured using Solid State Nuclear Track Detector (SSNTD) -spark counter based passive technique. A plastic twin chamber radon -thoron dosimeter was developed and standardized for the survey. This radon-thoron discriminating dosimeter uses three SSNTDs; two of which are exposed in cup modes and the third one is exposed in bare mode. Calibration factors (CF) are obtained for cup and bare mode SSNTDs through controlled experiments in a calibration facility. Calibration factors obtained from experiments showed very good agreement with the calibration factors derived from theoretical models. Four nodal centres were set up each at Kalpakkam, Jodhpur, Jaduguda and Mumbai for calibration and standardization of the dosimeter system. Inter calibration of the dosimeters were also carried out for comparison purpose. Nearly 4500 measurements in about 1400 dwellings were made during the survey period. An analysis of the data shows that the indoor radon gas concentrations at different locations vary between 4.6 and 147.0 Bq.m -3 with a geometric mean of 23.0 Bq.m -3 (GSD 2.61). Indoor thoron gas concentrations, in general, are found to be less than the radon concentrations and vary from 3.6 to 42.8 Bq.m -3 with a geometric mean of 12.2 Bq.m -3 (GSD 3.22). The mean annual inhalation dose rate due to radon, thoron and their progeny in the dwellings is estimated to be 0.97 mSv.y -1 (GSD 2.49). It is observed that the major contribution to the indoor inhalation dose is due to radon and its progeny. However, the contribution due to thoron and its progeny is not trivial as it is about 20 % of the total

  19. A study of diurnal variations of radon and thoron concentrations in different indoor environmental conditions

    International Nuclear Information System (INIS)

    Pant, Preeti; Prasad, Mukesh; Ramola, R.C.

    2015-01-01

    The measurements for diurnal variations in radon ( 222 Rn) and thoron ( 220 Rn) concentrations were performed in the different indoor conditions of Tehri Garhwal, Uttarakhand, India by using AlphaGUARD, Portable Radon Monitor and RAD7. While selecting the dwellings, the ventilation conditions, building materials, life style of the inhabitants and their exposure time indoors were also considered. The behavior of indoor radon and thoron concentrations was observed for different type of dwellings with different environmental conditions. The measurement techniques, results obtained and comparison of the results are discussed in details. (author)

  20. Radon and thoron progeny levels in air samples at Udagamandalam region of Nilgiris in India

    International Nuclear Information System (INIS)

    Manikandan, N.M.; Selvasekarapandian, S.; Sivakumar, R.; Raghunath, V.M.; Sundaram, V.M.; Santhanam, S.

    2002-01-01

    Measurement of concentration of radon and thoron daughter products in various indoor environment covering four seasons of a year in Udagamandalam Taluk of Nilgiris biosphere has been carried out using a high volume air sampler to assess the inhalation dose to the population which delivers higher dose than the radon and thoron gas alone. The potential alpha-energy concentrations of the radon and thoron progeny ranged from 0.97 to 12.72 mWL and from 1.63 to 15.83 mWL with a geometric mean of 6.02 and 7.89 mWL, respectively, taking all seasons into account. These measurements have yielded a wealth of data on the variation among the indoor radon and thoron progeny in various places during different seasons. The radon and thoron progeny levels are higher in winter seasons and are less in summer season with autumn and spring data lie in between winter and summer. Using the dose conversion factor for indoor exposures given in UNSCEAR 93 report the internal equivalent dose to the inhalation of radon progeny is evaluated to be 1357 μSv x y -1 and the corresponding annual effective dose equivalent value has been found to be 2.13 mSv x y -1 . It can be observed that the mean value of radon is higher than the Indian average. Also it is found the radon and thoron progeny levels are higher in the case of houses built with rock and granite and in tiled type houses of nearly 100 years old. The levels are less in the case of houses built with brick and cement. The observed results for different types of houses and seasons are discussed in this paper. (author)

  1. CANALPH-3: a portable three-channel alpha spectrometer for measuring the daughter products of radon and thoron

    International Nuclear Information System (INIS)

    Carson, D.W.

    1979-07-01

    A portable three-channel alpha spectrometer for the measurment of radon and thoron daughters in uranium mines or homes is described. The computer programs for analysing the data to give the working levels of radon and thoron by both the alpha spectrometric and modified Kusnetz methods are included along with some typical results

  2. 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)

  3. Variability of radon and thoron equilibrium factors in indoor environment of Garhwal Himalaya.

    Science.gov (United States)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Kandari, Tushar; Gusain, G S; Mishra, Rosaline; Ramola, R C

    2016-01-01

    The measurements of radon, thoron and their progeny concentrations have been carried out in the dwellings of Uttarkashi and Tehri districts of Garhwal Himalaya, India using LR-115 detector based pin-hole dosimeter and DRPS/DTPS techniques. The equilibrium factors for radon, thoron and their progeny were calculated by using the values measured with these techniques. The average values of equilibrium factor between radon and its progeny have been found to be 0.44, 0.39, 0.39 and 0.28 for rainy, autumn, winter and summer seasons, respectively. For thoron and its progeny, the average values of equilibrium factor have been found to be 0.04, 0.04, 0.04 and 0.03 for rainy, autumn, winter and summer seasons, respectively. The equilibrium factor between radon and its progeny has been found to be dependent on the seasonal changes. However, the equilibrium factor for thoron and progeny has been found to be same for rainy, autumn and winter seasons but slightly different for summer season. The annual average equilibrium factors for radon and thoron have been found to vary from 0.23 to 0.80 with an average of 0.42 and from 0.01 to 0.29 with an average of 0.07, respectively. The detailed discussion of the measurement techniques and the explanation for the results obtained is given in the paper. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Somogyi, G.; Varga, Zs.

    1983-01-01

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

  5. Radon and thoron concentrations in offices and dwellings of the Gunma prefecture, Japan

    International Nuclear Information System (INIS)

    Sugino, M.; Tokonami, S.; Zhuo, W.

    2005-01-01

    A one year survey of indoor radon and thoron concentrations was carried out in offices and dwellings of the Gunma prefecture, Japan. A passive integrating radon and thoron discriminative monitor was used in the survey. The annual mean radon concentration was 22±14 Bq x m -3 , and ranged from 12 to 93 Bq x m -3 among the 56 surveyed rooms. Radon concentration in offices was generally higher than that in the dwellings, with the arithmetic averages of 29 and 17 Bq x m -3 , respectively. Radon concentrations were generally lower in the traditional Japanese wooden houses than those houses built with other building materials. Seasonal variation of indoor radon was also observed in this survey. Compared to summer and autumn, radon concentrations were generally higher in spring and winter. The mean value of thoron to radon ratio was estimated to be 1.3, higher values were observed in the dwellings than in the offices. The annual effective dose from the exposure to indoor radon was estimated to be 0.47 mSv after taking the occupancy factors of offices and dwellings into account. (author)

  6. Radon and Thoron emanation testwork on Nolans Rare Earths ores

    International Nuclear Information System (INIS)

    Sonter, Mark; Grose, Jeremy

    2016-01-01

    This paper reports on a series of experiments performed on two bulk ore samples for Arafura Resources' Nolans Rare Earths project, intended to derive information on radon (Rn222) and thoron (Rn220) emanation rates (fluxes) under various circumstances. This data is needed to enable development of predictions of Rn and Tn releases from exposed mine bench ore, ore stockpiles, and tailings, and thus assist in estimation of airborne concentrations within the areas of the future Mine and Processing plant. In turn these estimates will provide guidance on the quantitative risk and the necessity or otherwise of invoking specific control measures, either in design or in operating procedures. This testwork was carried out during the period 2nd to 15th July, at Arafura's Winnellie facility in Darwin. Conclusions are that for uncrushed ore, Rn flux numbers are around 1.0Bq/m"2/s, Tn numbers appear to cluster around 200-300 Bq/m"2/s. Crushing gave no change in Rn flux, Tn flux was doubled for calc-silicate material. Wetting gave significant reductions for both Rn and Tn for ores sampled, and clay capping reduced Rn flux marginally but Tn was reduced by a factor of 100.

  7. Measurement of radon and thoron present in the environment using nuclear track etch detector technique

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Lalit, B.Y.; Mishra, U.C.

    1986-01-01

    The use of solid state nuclear track detectors (SSNTD) is one of the most convenient techniques to assess the average radiation levels of alpha activities in the environment. This technique has been used to assess the radon and thoron concentrations in some high background areas of South India and underground non-uranium mines in Bihar State. Exposed SSNTD films are chemically etched in an alkali solution and the alpha tracks are evaluated under an optical microscope. The detailed procedure for this study and the calibration of the etched films for conversion of alpha track density to radon and thoron concentrations in pCi l -1 are given in this paper. It was found that 1.9 tracks cm -2 day -1 and 6.2 tracks cm -2 day -1 were produced by exposing the LR-115 foils to 1 pCi l -1 of thoron and radon respectively. (author)

  8. Study of radon, thoron and toxic elements in some textile dyes

    International Nuclear Information System (INIS)

    Abel-Ghany, H.A.

    2013-01-01

    Elemental analysis of textile dyes may provide valuable information concerning the content and concentrations of element, especially the toxic ones. Such information monitors the safety of handling and using these dyes in textile industry. In addition to the safety of wearing of clothes stained with these dyes. In the present work, the specific activity of both radon and thoron were measured in nine textile dyes by using alpha emitters registration which are emitted from radon and thoron gases in CR-39 nuclear track detectors. Unexpectedly, the results obtained reports a high concentration of both radon and thoron gases in some samples (samples D5 and D9). Also the concentration of toxic elements (Cu, Pb, Zn, Mn, Cd and Cr) in textile dyes were determined by flame and graphite furnace atomic absorption spectrometry. (author)

  9. The measurement of radon and thoron by solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Khan, H.A.; Akhwand, R.A.; Bukhari, K.M.; Saddarudin, A.

    1976-01-01

    Experiments have been conducted to study a) the development and annealing properties of the latent damage trails produced by radon/thoron alpha particles in plastic Solid State Nuclear Track Detectors (SSNTDs), and b) the diffusion properties of radon and thoron in various media by using SSNTDs. The information thus obtained has been employed for a) the optimization of the conditions for the construction of radon/thoron dosimeters for uranium/thorium mines, and b) the use of SSNTDs for the prospection and estimation of uranium and thorium. The results indicate that these gases can diffuse even through rocks, and cellulose nitrate detectors, LR-115 and CA80-15, can be profitably employed in dosimetry, prospection, and for the discrimination between uranium and thorium deposits. (orig.) [de

  10. Variability of radon and thoron equilibrium factors in indoor environment of Garhwal Himalaya

    International Nuclear Information System (INIS)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Kandari, Tushar; Gusain, G.S.; Mishra, Rosaline; Ramola, R.C.

    2016-01-01

    The measurements of radon, thoron and their progeny concentrations have been carried out in the dwellings of Uttarkashi and Tehri districts of Garhwal Himalaya, India using LR-115 detector based pin-hole dosimeter and DRPS/DTPS techniques. The equilibrium factors for radon, thoron and their progeny were calculated by using the values measured with these techniques. The average values of equilibrium factor between radon and its progeny have been found to be 0.44, 0.39, 0.39 and 0.28 for rainy, autumn, winter and summer seasons, respectively. For thoron and its progeny, the average values of equilibrium factor have been found to be 0.04, 0.04, 0.04 and 0.03 for rainy, autumn, winter and summer seasons, respectively. The equilibrium factor between radon and its progeny has been found to be dependent on the seasonal changes. However, the equilibrium factor for thoron and progeny has been found to be same for rainy, autumn and winter seasons but slightly different for summer season. The annual average equilibrium factors for radon and thoron have been found to vary from 0.23 to 0.80 with an average of 0.42 and from 0.01 to 0.29 with an average of 0.07, respectively. The detailed discussion of the measurement techniques and the explanation for the results obtained is given in the paper. - Highlights: • Equilibrium factors for indoor radon, thoron and their progeny were measured. • Recently developed passive detector techniques were used for measurements. • The values of equilibrium factors are comparable with world's average values. • Equilibrium factor should be measured separately for individual dwelling. • Separate values of equilibrium factors are useful to produce actual radiation dose.

  11. The influence of thoron on measurement results of radon exhalation rate

    CERN Document Server

    Xiao De Tao; Ling Qiu; Leung, J K C

    2002-01-01

    Because of thoron exhalation, the measurement results of radon exhalation rate using a local still method is usually larger than the true value of radon flux rate of the monitored material surface. The influence of sup 2 sup 1 sup 6 Po(ThA) on radon exhalation rate can be eliminated for sensitive radon monitors. Theoretical evaluations of the influence of sup 2 sup 1 sup 2 Bi(ThC) and sup 2 sup 1 sup 2 Po(ThC')on radon exhalation rate are carried out in a sampler with diameter of 188 mm, and height of 125 mm, and supplied electrostatic field inside (generated by high voltage and electret) under following conditions: the sampling time are 1, 2, 3 h, respectively, thoron exhalation rate is 100 times of radon's. The calculation results indicate that the measurement results of radon flux rate are possibly 35.5% larger than true value due to the influence of thoron for fast and multifunctional radon monitors with electret, high voltage, respectively and using CR-39 SSNTD as detector, but this influence is negligib...

  12. 220Radon (Thoron) and progeny exposures in the front-end of nuclear fuel cycle activities with special reference to radioactive minerals, thorium and rare earths processing

    International Nuclear Information System (INIS)

    Pillai, P.M.B.

    2008-01-01

    Radon is a major Source of radiation exposure both at home and work places due to its universal presence. The International Commission on Radiological Protection has always treated the radioactive noble gas radon ( 222 Rn) and its isotope thoron ( 220 Rn) as a separate subject. ICRP Publication 65 (ICRP, 1993) summarizes the current knowledge of health effects of inhaled radon and its decay products and gives recommendations/guidelines for the control of exposures due to high radon levels encountered in dwellings and work places. A major departure from earlier publications on the subject is the entirely epidemiological considerations for developing the recommendations. In work place monitoring the progeny concentrations are of primary concern than the gases themselves. However radon/thoron gas measurements may also be used provided reliable information on the equilibrium factors are available. Though many developments have taken place and many options are available for individual monitoring for radon (mainly progeny) exposures of occupational workers, a viable personal dosimeter for individual monitoring for thoron daughters is yet to materialize. The doses are mostly estimated by making use of work place monitoring data in combination with occupancy factors

  13. Determination of radon and thoron permeability through some plastics by track technique

    Energy Technology Data Exchange (ETDEWEB)

    Hafez, A.-F.; Somogyi, G.

    1986-01-01

    Experiments have been performed to study the usefulness of several types of plastic foils as filter to separate radon and thoron. Time-integrated alpha-activity measurements have been carried out by using the so-called ''can-technique'' equipped with both LR-115 and CR-39 track detectors. The track density observed on the detectors, taken as a measure of radon activity concentration, has been determined as a function of the thickness of filter foils. The radon permeability and the thoron separation factors have been determined. It is shown that various plastic foils exhibit considerable differences in radon diffusion coefficient owing to their different chemical structures. Among the plastic foils investigated the polyethylene proved to have the highest gas diffusion coefficient.

  14. Refinement of a thoron insensitive alpha track detector for environmental radon monitoring

    International Nuclear Information System (INIS)

    Davey, J.F.

    1995-01-01

    Olympic Dam Operations, a Copper/Uranium mine in the north of South Australia, currently monitors environmental radon (Rn 222) concentrations at a total of 17 sites in the area surrounding the mining lease and Roxby Downs township. During 1990 a commercial alpha track radon detector service was replaced with an on-site system resulting in lower costs, greater confidence in detector calibration, and reduction in processing time. Alpha track detectors (ATD's) are placed in triplicate at each of the 17 sites. Flow-through scintillation cell continuous radon monitors are also operated at two of these sites. Comparison of results from the two different types of monitor has raised the question of a possible thoron (Rn 220) contribution in the alpha track detectors. Laboratory experiments revealed that the diffusion membranes used in the ATD's were in fact 'transparent' to thoron. A new membrane was tested which effectively excluded thoron from the detector cup without affecting the sensitivity to radon. Field comparisons of the different membranes revealed that the thoron component was significant. Since there is only a very minor Rn220 emission from the mining operation, it is important that the monitoring be specific only to Rn222, the primary source term. The use of the new membrane will result in more accurate measurements of Rn222. 4 refs., 4 tabs., 5 figs

  15. 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.

  16. International intercalibration and intercomparison programme for radon, thoron and daughters measuring equipment. Part. 1: Radon measurement

    International Nuclear Information System (INIS)

    Knutson, E.O.; Solomon, S.B.

    1986-01-01

    The International Intercalibration and Intercomparison Programme for Radon, Thoron and Daughters Monitoring Equipment, abbreviated IIIP, is a program organized jointly by Nuclear Energy Agency of the Organization for Economic Cooperation and Development and the Radiation Protection Research Programme of the Commission of European Communities. The broad purpose of the IIIP is to determine if the somewhat diverse calibration procedures used in different countries are equivalent. The general approach was to select four regional reference laboratories and entrust them with the details of project definition and execution. The four selected laboratories are: Australian Radiation Laboratory, US DOE Environmental Measurements Laboratory, UK National Radiation Protection Board, US DOI Bureau of Mines. The Organizing Committee that selected the four laboratories remained intact and served an oversight function in all work to date

  17. 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.

  18. 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.

  19. Concentrations of indoor radon and thoron in cave-dwellings with discussions on risk estimation of lung cancer

    International Nuclear Information System (INIS)

    Sun Quanfu; Hou Changsong; Zhang Shouzhi; Nie Xiaoqian; Shang Bing

    2005-01-01

    Objective: To explore a residential area with elevated indoor radon exposure for conducting epidemiological studies on indoor radon and lung cancer. Methods: Two hundred and two cave-dwellings (CD) including loess CD, brick CD, stone CD, and ordinary house in twenty villages were selected from Yan'an and Lvliang in the Chinese loess plateau. Indoor levels of thoron and its progeny as well as radon were measured with passive radon-thoron discriminative detectors and thoron progeny deposition rate devices. The exposure period covered from August 2001 through August 2002. Results: Loess CD was one of the most common type of dwelling caves in both areas. The indoor radon concentrations in loess CD ranged from 17 to 179 Bq/m 3 ; thoron varied sub-stantially depending upon the distance from the device to the wall, ranged from 10 to 760 Bq/m 3 . Geometric means of indoor radon, thoron and thoron's progeny (EEC Tn ) of loess caves in Yan'an area were estimated to be 71, 185 and 2.2 Bq/m 3 , respectively, and the corresponding figures were 73, 145 and 116 Bq/m 3 in Lvliang area. Possible contamination of thoron on radon measurement in a previous case-control study on lung caner was discussed. The study revealed that the indoor air pollution in Yan'an area was slight compared with that in Lvliang area. Migration was very low. Eighty-six percent of the investigated persons have had no migration in Yan'an area, and 90 percent of the cave-dwellings where the subjects once resided were available to our measurements. Two million people have been living in cave-dwellings over several generations. Conclusion: The investigated cave-dwelling area in Yan'an is suitable for conducting epidemiological study on residential thoron and radon exposure and lung cancer.(authors)

  20. Assessment of dose due to exposure to indoor radon and thoron progeny

    Directory of Open Access Journals (Sweden)

    Prasad Ganesh

    2010-01-01

    Full Text Available The components of the effective dose through inhalation from radon and its progeny are important for human health since they contribute to more than 50% of the total radiation dose from natural sources. As a consequence, radon has been identified as the second leading cause of lung cancer after smoking. Radon and its short lived decay products (218Po, 214Pb, 214Bi, 214Po present in dwellings are a radiation hazard, particularly if such sources are concentrated in the enclosed areas like poorly ventilated houses and underground mines. The indoor radon, thoron, and progeny concentrations were measured in a small hilly town of Budhakedar and the surrounding area of Tehri Garhwal, India, by using LR-115 Type II plastic track detector in a twin cup radon dosimeter. The concentrations of radon progeny were measured as the highest in winter and the lowest in summer while the thoron progeny concentration was found maximum in rainy season and minimum in autumn. The annual exposure to the potential alpha energy of radon and thoron were found to vary from 0.04 WLM to 0.69 WLM with an average value of 0.29 WLM, and 0.03 WLM to 0.37 WLM with an aver- age value of 0.16 WLM, respectively. The annual effective dose due to the exposure to indoor radon and progeny in Budhakedar homes was found to vary from 0.16 mSv to 2.72 mSv with an average value of 1.14 mSv and the effective dose due to the exposure to thoron and progeny was found to vary from 0.18 mSv to 2.49 mSv with an average value of 1.05 mSv. The results of systematic study have been obtained by considering the room as a space in which the radon and thoron levels are directly related to the dynamic and static parameters.

  1. An approach to discriminatively determine thoron and radon emanation rates for a granular material with a scintillation cell

    International Nuclear Information System (INIS)

    Sakoda, Akihiro; Meisenberg, Oliver; Tschiersch, Jochen

    2016-01-01

    A powder sandwich technique was applied to determine thoron ("2"2"0Rn) and radon ("2"2"2Rn) emanation rates for a granular material. The feature of this technique is the sample preparation, in which a granular material is put and fixed between two membrane filters. Airflow is directly given to this sandwich sample, will include thoron and radon emanated from the material, and then is transferred to the detector. This method makes sure that thoron and radon emanated are not retained in pore space within the sample volume, which is crucial for the appropriate emanation test. This technique was first introduced by Kanse et al. (2013) with the intention to measure the emanation of thoron - but not of radon - from materials having much higher "2"2"4Ra activity than "2"2"6Ra. In the present study, the methodology for the discriminative determination of thoron and radon emanation rates from a granular material has been examined using a flow-through scintillation cell and sandwich sample. The mathematical model was developed to differentiate total alpha counts into thoron- and radon-associated counts. With a sample of uranium ore, this model was experimentally validated by comparison between the scintillation cell and a reference detector that can discriminatively measure thoron and radon concentrations. Furthermore, the detection limits and uncertainties were evaluated to discuss the characteristics of this method. Key parameters for improving the determination of thoron and radon emanations were found to be the background radon concentration and the leakage of radon from the measurement system, respectively. It was concluded that the present method is advantageous to a sample that has much higher "2"2"6Ra activity than "2"2"4Ra. - Highlights: • The methodology of appropriate and discriminative measurement of thoron and radon emanation is presented. • Measurement of thoron and radon emanated from a sample was made using a scintillation cell. • Detection limits and

  2. Measurement of radon and thoron progeny size distributions and dose assessments at the mineral treatment industry in Thailand

    International Nuclear Information System (INIS)

    Chutima Kranrod; Supitcha Chanyotha; Nares Chankow

    2013-01-01

    A new portable type cascade impactor has been developed to determine the activity size distribution of radon and thoron progeny in a natural environment more efficiently. The modified impactor consists of 4 stages with a back up filter stage for the collection of aerosol samples. The aerosol cut points in the impactor are set for 10, 2.5, 1 and 0.5 μm at a flow rate of 4 L min -1 . Five CR-39 chips were used as alpha detectors for each stage. In order to separate α particles emitted from radon and thoron progeny, CR-39 detectors are covered with aluminum-vaporized Mylar films. The thickness of each film is adjusted to allow α particles emitted from radon and thoron progeny to reach the CR-39 detectors. The technique has been successfully tested in field studies, particularly inside a mineral treatment industry in Thailand to estimate doses in the working environment. The dose calculations by lung dose evaluation program showed that activity median aerodynamic diameters played a significant role in determining the particle size distributions of the attached radon and thoron progeny. The dose conversion factor determined from short term measurements due to exposure from the inhalation of thoron and its progeny was found to be 4 times higher than comparable values for radon and its progeny. The effective dose for workers exposed to radon is about 4-6 times higher than thoron. (author)

  3. Radon, thoron and their progeny levels in some dwellings of Union Territory Chandigarh, India using SSNTDs

    International Nuclear Information System (INIS)

    Mehta, Vimal; Kumar, Amit; Chauhan, R.P.; Mudahar, G.S.

    2013-01-01

    Indoor air quality is an important issue for protection against adverse health effects caused by the inhalation of pollutants because most individuals spend 90% of their time indoors and that indoor air quality is deteriorated by a large variety of sources. Out of these sources radon is a major pollutant and is an important global problem of radiation hygiene. Radon and its progeny are the major contributors in the radiation dose received by general population of the world. Next to cigarette smoking, the inhalation of radon gas and the products of its radioactive disintegration are considered the most significant cause of lung cancer. Due to the potentially serious public health implications of exposure to high levels of radon, the environmental monitoring of radon, thoron and their progeny in some dwellings of Chandigarh, union territory of India has been carried out. The radon-thoron twin dosimeter cups were used for the study. The aim of the study is the possible health risk assessment in the dwellings under consideration. (author)

  4. 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)

  5. 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

  6. Development on high precision monitoring technique of radon and thoron in environment

    International Nuclear Information System (INIS)

    Imaizumi, Masayuki; Hamada, Hiromasa; Goto, Masahiro; Nakazato, Hiroomi; Mori, Mitsuhiro

    1999-01-01

    In a field of the environmental management, many technical research and developments such as monitoring on drainage section and flowing speed change of groundwater, analysis on alternating flow phenomenon between surface water and groundwater, analysis on water leakage at a dam, forecasting of landslide, safety evaluation on ground due to detection of faults, have conducted. And, an application to analysis on gas flowing phenomenon from underground to atmosphere as a part of study on evaluation of effect of gas emitted from earth surface on the earth environment was investigated. This study aimed to elucidate behaviors of radon and thoron at environment and to develop a high precision monitoring technique on radon and thoron required to conduct an advanced application to a tracer in hydrology, applied geology, and environment engineering. (G.K.)

  7. Elevated radon and thoron concentrations from natural radioactivity in building materials

    International Nuclear Information System (INIS)

    Smith, D.; Vivyurka, A.

    1980-01-01

    Radon levels in excess of 20 mWL were observed in an apartment building under construction in Elliot Lake. Tracer studies showed ventilation periods as long as 29 hours since the ventilation system of the building was not yet working. It was concluded that, once the contribution from thoron daughters was taken into account, the natural radioactivity of the concrete and other building materials was sufficient to produce the observed levels of radioactivity

  8. 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)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  11. Study on seasonal variation of indoor radon, thoron and their progeny levels in Hassan District of Karnataka, India

    International Nuclear Information System (INIS)

    Srinivasa, E.; Rangswamy, D.R.; Sannappa, J.

    2015-01-01

    Radon, thoron and their progeny concentrations have been measured in different types of buildings at different locations for different seasons in Hassan city using time-integrated passive radon dosimeters containing LR-115 Type II solid state nuclear track detector exposed for four seasons of 3 months each covering a period of one year from October 2012 to September 2013. The radon and thoron activity concentration in summer season in the corresponding dwellings has been found to vary from 7.4 to 45.7 Bq m -3 and 5.4 to 34.9 Bqm -3 with a median of 23.59±11 Bqm -3 and 1447±8 Bq -3 respectively. The radon progeny concentrations varies from 0.4 to 4.1 mWL with an average value of 1.83±1 mWL, while thoron progeny concentrations vary from 0.3 to 3.2 mWL with an average value of 1.12±0.7 mWL respectively. The annual effective dose received due to radon, thoron and its progeny by the inhabitants in the dwellings under study has also been calculated which is found to vary from 0.320±0.4 to 1.860 ±1.1 mSv y -1 with an average value of 0.9576 ± 0.8 mSv y -1 . In general, the level of radon-thoron was observed highest in winter and lowest in summer. A detail analysis of radon and thoron distribution in different houses with seasonal variation is presented in this paper. From this study it is observed that, bathrooms and kitchens have significantly higher radon concentrations as compared to other rooms in the dwellings. (author)

  12. Radiation exposure in homes through radon and thoron daughter products

    International Nuclear Information System (INIS)

    Schmier, H.

    1984-01-01

    In a random selection of about 6000 homes in the Federal Republic of Germany, the radon concentration in room air has been measured using a simple dosemeter developed by Karlsruhe Nuclear Research Centre. The mean radon concentration has been determined to be approximately 40-50 Bqu/m 3 . If this experiment is taken as a representative survey for the FRG, the mean dose contributed by the natural radiation exposure through radon and its short-lived decay products to the effective annual dose to the lungs can be computed to be about 1 mSv (100 mrem), using the internationally accepted conversion factors. Apart from this survey, special radon measuring programmes have been carried out, including simultaneous recording of meteorological data, in order to obtain information on the parameters to be taken into account when describing the daily variations of radon concentrations. (orig./DG) [de

  13. Thoron and radon progeny concentration measurements using direct progeny sensors in HLNRAs of Kerala

    International Nuclear Information System (INIS)

    Mishra, R.; Prajith, R.; Gole, A.C.; Kanse, S.D.; Chougaonkar, M.P.; Sapra, B.K.; Mayya, Y.S.; Jayalekshmi, P.; Nair, Raghu Ram K.

    2010-01-01

    Passive Progeny Dosimeters (PPDs) were deployed in 500 houses in 3 villages namely Allapad, Chavara and Neendakara villages of Karunagapally Taluk of Kollam district of Kerala. Each PPD unit is a combination of a DTPS and a DRPS placed side-by-side for time integrated thoron and radon progeny concentration estimation respectively. The PPDs were suspended vertically in the rooms, such that the nearest distance from any wall or surface was at least 30 cm. These are, as of now, being exposed for a period of 3 months, after which they will be retrieved and analysed by chemical etching and track counting. Simultaneously, external gamma radiation measurements have also been made using a survey meter; these showed a variation from 13 to 118 μR/h in indoors and 21 to 213 μR/h in the outdoor environments. Spot measurements of thoron progeny concentrations were also made in 7 selected houses using the conventional grab filter-paper sampling technique at a flow-rate of 21 min -1 for 30 minutes, followed by alpha counting. The average thoron progeny concentration was found to be 2.0 ± 0.7 Bq m -3 . In the outdoor environment, filter-paper sampling was carried out for 2 hours at 21 min -1 and the thoron progeny concentration was measured as 2.96 Bq m -3 . To corroborate these measurements, a flow mode integrated sampler which uses the DTPS and DRPS elements was used

  14. Development of a PIN diode based on-line measurement system for Radon (222Rn) and Thoron (220Rn) in environment

    International Nuclear Information System (INIS)

    Ashokkumar, P.; Chaudhury, Probal; Sumesh, C.G.; Sahoo, B.K.; Gaware, J.J.; Mayya, Y.S.

    2014-01-01

    Radon, thoron and their progenies are universally present in outdoor air, and can reach higher levels in indoor air due to poor ventilation. Several instruments have been developed for accurate measurement of radon and thoron in the environment. Semiconductor detector based system employing spectroscopic method has been proved to be the best among them. A PIN diode based electrostatic collection type online real-time instrument has been developed in Bhabha Atomic Research Centre for simultaneous measurement of radon and thoron in an environment while both 222 Rn and 220 Rn are present. This system can be used for determination of radon and thoron concentrations at residence or workplace. Furthermore, since the 222 Rn and 220 Rn are differentiated from each other through spectroscopy, this monitor can be used even in a mixed radon/thoron environment

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

    International Nuclear Information System (INIS)

    Mayya, Y.S.

    2008-01-01

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

  16. Comparison of indoor radon and thoron concentrations in the urban and rural dwellings of Chhattisgarh state of India

    International Nuclear Information System (INIS)

    Khokhar, M.S.K.; Kher, R.S.; Rathore, V.B.; Pandey, S.; Ramachandran, T.V.

    2008-01-01

    In the frame of nationwide radon/thoron monitoring program, indoor radon/thoron and their progeny concentrations have been estimated for 210 dwellings situated in 8 towns (urban) and 9 villages (rural) of Chhattisgarh state of India. The measurement has been made on quarterly integrating cycle for one full year in each dwelling. Twin chamber dosimeter cup with LR-115 Type-II Solid State Nuclear Track Detector was used for the measurement of indoor radon/thoron concentration. The results show that the geometric mean of indoor thoron concentration in urban dwellings varies from 11.57 to 25.88Bqm -3 with an overall geometric mean value of 16.65Bqm -3 , while in rural dwellings it varies from 12.50 to 30.08Bqm -3 with an overall geometric mean value of 19.00Bqm -3 . The potential alpha energy concentration (PAEC) levels of thoron in the urban and rural dwellings are found to be 2.58 and 4.57 mWL, respectively. Similarly, the geometric mean of indoor radon concentrations in urban dwellings is found to vary from 20.20 to 30.13Bqm -3 with an overall geometric mean value of 25.28Bqm -3 , while in rural dwellings it varies from 15.50 to 36.05Bqm -3 with an overall geometric mean value of 27.32Bqm -3 . The PAEC levels of radon in the urban and rural dwellings are found to be 1.50 and 1.87 mWL, respectively. The dose contribution of thoron and progeny in total inhalation dose has been found to be more than 20% in all the surveyed places that show the necessity to pay attention to the presence of thoron and progeny from public health point of view

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

    International Nuclear Information System (INIS)

    Bigu, J.; Grenier, M.

    1982-03-01

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

  18. Inhalation dose due to indoor radon and thoron concentrations in the surrounding villages of Hyderabad, Andhra Pradesh, India

    International Nuclear Information System (INIS)

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

    2006-01-01

    Inhalation of radon, thoron and their decay products is the major contribution to the total radioactive dose received by the human population from the natural radiation. The indoor inhalation doses due to radon, thoron and their progenies in the surrounding villages of Hyderabad, India are evaluated. The average inhalation dose due to radon and its progeny is found to be 0.26 ± 0.21 mSv y -1 and due to thoron and its progeny is 0.35 ± 0.38 mSv y -1 . The inhalation dose is also analyzed based on the types of floor, roof and walls of the dwellings and it is found that the dwellings with mud type construction materials have higher inhalation dose. Generally, the contribution of thoron and its progeny to the total dose is neglected but in the present study area the fractional dose of thoron and its progeny is found to be comparable to that of radon and its progeny. (author)

  19. A new method for studying the transport of radon and thoron in various building materials using CR-39 and LR-115 solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Ktata, A.; Bakhchi, A.

    2000-01-01

    Radon ( 222 Rn) and thoron ( 220 Rn) α-activities per unit volume were measured inside and outside different building materials by using two types of solid state nuclear track detectors (SSNTD) (CR-39 and LR-115 type II). In addition, the radon and thoron emanation coefficients of the studied materials were evaluated. Based on these data, the transport of radon and thoron across parallelepipedic blocks of the building materials could be investigated and radon and thoron global α-activities per unit volume outside different building material blocks were determined. Moreover, the diffusion length and the effective diffusion coefficient of radon in the building materials were evaluated and the total alpha activity due to radon in the atmospheres of different rooms consisting of different building materials was studied

  20. Study of Indoor Radon /Thoron And Its Hazard Inside Kindergartens In Iraqi Kurdistan Using CR39 Nuclear Track Detectors

    International Nuclear Information System (INIS)

    Ismail, A.H.

    2007-01-01

    Indoor radon /thoron levels with potential alpha energy concentration PAEC), effective dose (H E ) and equilibrium factor (F) were measured using closed and open-can technique, containing CR-39 nuclear track detector. Measurements were carried during summer season inside different Kindergartens in three main regions (Erbil, Duhok and Sullimaniye) in Iraqi Kurdistan. We found that the radon and thoron densities range from (11 to 33 track.cm -2 .d -1 ) for radon and (8 to 29 track.cm -2 .d -1 ) for thoron, with the average radon concentration (96.81 26.939Bq/m 3 ) While an average (PAEC) and (H E ) was (7.68±2.298 mWL) , (2.306± 0.689 mSv/Y) respectively. On the other hands the average equilibrium factor was (0.291±0.01). Consequently, we believe that our results were done when we comparing them with the action levels were recommended by (lCRP 66). The results obtained indicate that various locations have different values of radon/thoron concentration. The differences can be ascribed to variations in grades of uranium at different locations and to some environmental factors such as ventilation, particle concentration, and the deposition of the progeny on surfaces or on the atmospheric aerosol

  1. Radon and thoron emanation measurements and the effect of ground water

    International Nuclear Information System (INIS)

    Carriveau, G.W.; Harbottle, G.

    1980-01-01

    In the past, corrections for annual dose rate calculations have used a qualitative approach to the effect of ground water saturation and radon and thoron loss. An example is presented of how this correction can now be precisely determined using natural gamma-ray activities to determine the amount of emanation from ceramic sherds and soil, both in a dry state and saturated with ground water. The experimental data also provide information concerning disequilibria in 234 Th and 226 Ra regions of the decay series. Additionally, approximate values of uranium and thorium concentrations (sufficiently accurate for authenticity work) are provided

  2. Cellular lung dosimetry for inhaled thoron progeny: comparison with radon progeny

    International Nuclear Information System (INIS)

    Abd El-Hady, M.; Hofmann, W.; Balashazy, I.

    1998-01-01

    Recently an analytical method was developed to compute radiation doses deposited by 222 Rn progeny alpha particles in 1 μm spheres located at different depths in bronchial epithelium. The same method was now applied to alpha particles emitted from 220 Rn progeny deposited in bronchial airway surfaces. Results of the computations are presented in graphs. The mean cellular doses imparted by 220 Rn progeny to basal and secretory cell nuclei were compared with those produced by 222 Rn progeny; due to differences in alpha energies, radon progeny doses were found to be generally higher than those for thoron progeny. (A.K.)

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

    Science.gov (United States)

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

    2016-10-01

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

  4. Comparison of radon and thoron daughter behaviour in two underground uranium mine environments

    International Nuclear Information System (INIS)

    1985-09-01

    Measurements were made of aerosol concentration and size distribution in 5 locations downstream of working areas in two Canadian uranium mines which use track and trackless mining methods. In the track mining area the aerosol concentration ranged from 3x10 4 to 7x10 4 /cm 3 , averaging 5x10 4 /cm 3 . The highest values were associated with the passage of diesel equipment. The count median diameter of the aerosol varied from 32 to 94 nm, with the smaller sizes associated with the presence of diesel exhaust. The activity median diameter was measured for radon and thoron daughters in each environment. In the track mine the diameter of 218 Po, 214 Pb, 214 Bi averaged 54, 50, 54 nm respectively, and of 212 Pb averaged 70 nm. In the trackless mine, these diameters were 73, 70, 85 and 100 nm, respectively. The activity median diameter in terms of radon Total Potential Alpha Energy was found to be 89 nm

  5. Underground measurements of aerosol in radon and thoron progeny activity distributions

    International Nuclear Information System (INIS)

    Khan, A.; Bandi, F.; Phillips, C.R.; Duport, P.

    1990-01-01

    Aerosol and activity distributions of 218 Polonium, 214 Lead, 214 Bismuth, and 212 Lead were determined in two different underground mining environments by means of an optimized time-delay counting scheme and diffusion batteries. In one environment, diesel equipment was operating; and in the other, electrically powered equipment. The two environments differed significantly in total aerosol concentration. In the diesel environment, in particular, aerosol concentrations were unsteady, and fluctuated with vehicular traffic and mining activities. As measured by radon progeny disequilibrium, the age of the air ranged from about 25 to 60 minutes. Thoron working levels were of the same order as radon working levels. In this paper, comparisons are made between the aerosol and activity size distributions in both the diesel and electric mine

  6. An intercomparison between gross α counting and gross β counting for grab-sampling determination of airborne radon progeny and thoron progeny

    International Nuclear Information System (INIS)

    Papp, Z.

    2006-01-01

    The instantaneous values of the airborne activity concentrations of radon progeny and thoron progeny have been determined 34 times in a closed and windowless room in a cellar using two independent grab-sampling methods in order to compare the performance of the methods. The activity concentration of radon ( 222 Rn) was also measured and it varied between 200 and 650 Bq m -3 . Two samples of radon and thoron progeny were collected simultaneously from roughly the same air volume by filtering. For the first method, the isotopes were collected on membrane filter and gross α counting was applied over several successive time intervals. This method was a slightly improved version of the methods that are applied generally for this reason for decades. For the second method, the isotopes were collected on glass-fibre filter and gross β counts were registered over several time intervals. This other method was developed a few years ago and the above series of measurements was the first opportunity to make an intercomparison between it and another similar method based on α counting. Individual radon progeny and thoron progeny activity concentrations (for the isotopes 218 Po, 214 Pb, 214 Bi and 212 Pb) were evaluated by both methods. The detailed investigation of the results showed that the systematic deviation of the methods is small but significant and isotope-dependent. The weighted averages of the β/α activity concentration ratios for 218 Po, 214 Pb, 214 Bi, EEDC 222 (Equilibrium-Equivalent Decay-product Concentration of radon progeny) and 212 Pb were 0.99±0.03, 0.90±0.02, 1.03±0.02, 0.96±0.02 and 0.80±0.03, respectively. The source of the systematic deviation is probably the inaccurate knowledge of the counting efficiencies mainly in the case of the α-counting method. A significant random-type difference between the results obtained with the two methods has also been revealed. For example, the β/α ratio for EEDC 222 varied between 0.81±0.01 and 1.22±0

  7. Effect of ventilation on concentrations of indoor radon- and thoron-progeny: Experimental verification of a simple model

    International Nuclear Information System (INIS)

    Sheets, R.W.; Thompson, C.C.

    1993-01-01

    Different models relating the dependence of radon ( 222 Rn)- and thoron ( 220 Rn)-progeny activities on room ventilation rates are presented in the literature. Some of these models predict that, as the rate of ventilation increases, activities of thoron progeny decrease more rapidly than those of radon progeny. Other models predict the opposite trend. In this study alpha activities of the radon progeny, 218 Po, 214 Pb, and 214 Bi, together with the thoron progeny 212 Pb, were measured over periods of several days in two rooms of a closed, heated house. Effective ventilation rates were calculated from measured 214 Pb/ 214 Bi ratios. A simple model in which progeny concentrations decrease by radioactive decay and by dilution with outside air has been used to calculate 212 Pb/ 214 Pb ratios as a function of ventilation rate. Calculated ratios are found to correlate significantly with experimentally-determined ratios (R 2 ∼ 0.5--0.8 at p < 0.005) confirming that, for this house, thoron progeny activities decrease faster than radon progeny activities with increasing rates of ventilation

  8. Multi-parametric approach towards the assessment of radon and thoron progeny exposures

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Rosaline, E-mail: rosaline@barc.gov.in, E-mail: rosaline.mishra@gmail.com; Sapra, B. K. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mayya, Y. S. [Indian Institute of Technology, Mumbai (India)

    2014-02-15

    Conventionally, the dosimetry is carried out using radon and thoron gas concentration measurements and doses have been assigned using assumed equilibrium factors for the progeny species, which is inadequate pertaining to the variations in equilibrium factors and possibly due to significant thoron. In fact, since the true exposures depend upon the intricate mechanisms of progeny deposition in the lung, therefore an integrated approach for the assessment of progeny is essential. In this context, the recently developed deposition based progeny concentration measurement techniques (DTPS: Direct Thoron progeny sensors and DRPS: Direct Radon progeny sensors) appear to be best suited for radiological risk assessments both among occupational workers and general study populations. DTPS and DRPS consist of aluminized mylar mounted LR115 type passive detectors, which essentially detects the alpha particles emitted from the deposited progeny atoms on the detector surface. It gives direct measure of progeny activity concentrations in air. DTPS has a lower limit of detection limit of 0.1 Bq/m{sup 3} whereas that for DRPS is 1 Bq/m{sup 3}, hence are perfectly suitable for indoor environments. These DTPS and DRPS can be capped with 200-mesh type wire-screen to measure the coarse fraction of the progeny concentration and the corresponding coarse fraction deposition velocities as well as the time integrated fine fraction. DTPS and DRPS can also be lodged in an integrated sampler wherein the wire-mesh and filter-paper are arranged in an array in flow-mode, to measure the fine and coarse fraction concentration separately and simultaneously. The details are further discussed in the paper.

  9. Characterization of CR 39 nuclear track detector for use as a radon/thoron dosemeter

    International Nuclear Information System (INIS)

    Kandaiya, S.

    1988-02-01

    For the estimation of radon, thoron and their short-lived daughter products in air radon diffusion chambers with passive α-track etch detectors have been used. The report describes the properties of CR 39 track etch detectors in particular with respect to the spectrometric detection of α-particles in the energy range up to 8.77 MeV using chemical and a combination of chemical-electrochemical etching technique. In order to optimize the etching conditions for an α-energy discrimination in the energy range up to 8.77 MeV, the ECE track size diameter and the track density have been investigated as a function of the chemical pre-etching time using three electrical field strengths. In a mixed α-spectrum the contributions of various α-particles with energies between 4.6 to 8.77 MeV have been determined experimentally in CR 39 and compared with the spectral measurement using a surface barrier detector and the same irradiation geometry. Beside CR 39 detectors etched chemically and electrochemically, in addition surface barrier detectors and a Monte Carlo calculation have been used to evaluate the α-energy spectrum for thoron and its daughter products emitted by α-decays in the air volume and the plate-out of daughters at the inner surface on the diffusion chamber. (orig./HP) [de

  10. Study of radon and thoron gas behaviour in the air at the commercial centers in Rio de Janeiro and Pocos de Caldas city

    International Nuclear Information System (INIS)

    Castro, Carlos A.C.; Cardoso, Domingos D.

    2005-01-01

    The radon is a radioactive gas. It occurs naturally in the atmosphere coming from the decay of radium, with emission of alpha particles. There are three radon isotopes more known, of which the most important under the environmental point of view is the Rn-222, whose half life is 3.82 days. The radon and their descendants are responsible by more than 40 % of the natural radioactive dose received for the human beings inside the building. In doses above 4 pCi/l, given as occupational dose, can cause among other diseases, the lung cancer. The main source of radon inside the building is the soil. The incidence of radon inside the building varies according to the soil composition, the materials employed in its construction, the inside air temperature and humidity, time during the day, season and the ventilation process designed. The work was realized at the commercial centers in Rio de Janeiro and Pocos de Caldas, for methodology confirmation. It was utilized the passive (track detectors) and active (two filters technique. Kusnetz technique, Tsivoglou technique and alpha spectrometry technique) methods. The objective of this work was to analyze the radon and thoron concentrations levels in order to supply parameters upon the quality of the air in those commercial centers. (author)

  11. High sensitivity two filter radon/thoron detectors with a wire or nylon screen as a second filter

    International Nuclear Information System (INIS)

    Whittlestone, S.; Zahorowski, W.; Wasiolek, P.

    1994-12-01

    A study is made of the use of wire and nylon screens as a second filter in two radon or thoron detectors. It is shown that acceptable detection efficiency is obtained at flow rates comparable to those used in detectors in which other types of filter are used. The main advantage of the screens is their very low flow impedance. Several designs of detector which exploit this feature are discussed. Details are given of the performance of three prototypes: a 32 L radon detector with a limit of detection of 0.0027 Bq m -3 and power consumption of 25 watts; and a portable thoron emanometer capable of detecting fluxes as low as 1 m Bq m -2 s -1 . The radon detectors are rugged and simple. They can operate with no routine maintenance and are suited to remote locations where only infrequent technical support is available. 14 refs., 2 tabs., 9 figs

  12. Estimation of radiological dose from radon, thoron and their progeny levels in the dwellings of Shivamogga district, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamvi, D.R.; Sannappa, J.; Srinivasa, E.

    2018-01-01

    Among all natural radiation exposure to man, inhalation of radon, thoron and their progenies are the major contributor (50 %) to the dose from ionizing radiation received by the general population. Based on the results of epidemiological studies in Europe and North America, the World Health Organization (WHO) has recommended reducing the indoor radon reference level from 200 to 100 Bq.m -3 . In view of this, focus has now been given for simultaneous measurement of radon, thoron and their progeny concentration in indoor air and also to estimate radiological dose in the dwellings of the Shivamogga district. The geology of the Shivamogga district comprises different types of rock formation such as granites, schists, magnetites and gneisses, Meta basalt, laterites, quartz and chlorite schist, Graywacke etc. Present study was concentrating more in granite bed rock regions along with their surrounding regions

  13. Determination of Radon-222 and Thoron Concentration in Decorative Stone Warehouses Indoor Air and the Received Effective Dose by Staff

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mahvi

    2015-06-01

    Full Text Available Background: Radon is a colorless, odorless, and radioactive gas that can be emitted from decorative stones such as granite, marble, etc. Inhaling radon gas in a long period may cause for incidence of lung cancer among peoples. Material and Methods: In this cross-sectional descriptive study, Radon 222 and Thoron concentrations in background and indoor air were measured in four decorative stones warehouse using portable radon meter(RTM1688-2 model. Totally, 24 samples of 24- hours concentrations in indoor air and 24 samples of 4-hours concentrations of Radon 222 and thoron in the background air at three stages were measured. Then, received effective dose of Radon 222 and Thoron was calculated by UNSCEAR equations. Results: The mean radon concentrations for indoor and background air were 74±37 and 34±16 Bq/m3, respectively. The mean radon concentrations for indoor air in decorative stones warehouses for DSW1, DSW2, DSW3 and DSW4 were 72.50±34, 98.25±43, 34.42±18 and 88.92±51 Bq/m3, respectively. The received effective dose mean of Radon 222 and Thoron by the staff at 8 working hours was 0.53±0.18 and 0.05±0.03 mSv/y and in 16 working hours was 1.05±0.36 and 0.11±0.07 mSv/y, respectively. Generally, the mean received effective dose by staff from Radon at 8 and 16 working hours was 0.58±0.2  and 1.16±0.41 mSv/y, respectively. Conclusions: Radon concentration mean in indoor air and the received effective dose mean by staff was lower than the standards level. Decorative stone warehouses were the resources for accumulation of Radon gas that can be reduced by corrective actions.

  14. Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Kávási, Norbert, E-mail: norbert@fml.nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Social Organization for Radioecological Cleanliness, Veszprém (Hungary); Vigh, Tamás [Social Organization for Radioecological Cleanliness, Veszprém (Hungary); Manganese Mining Process Ltd., Úrkút (Hungary); Németh, Csaba [Social Organization for Radioecological Cleanliness, Veszprém (Hungary); University of Pannonia, Veszprém (Hungary); Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori [National Institute of Radiological Sciences, Chiba (Japan)

    2014-02-15

    During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C–21°C), low or high wind speed (max. 2.4 m s{sup −1}) and low or elevated aerosol concentration (130–60 000 particles m{sup −3}). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m{sup −3} and 550(497) Bq m{sup −3} in the bauxite mine; 887(604) Bq m{sup −3} and 1258(788) Bq m{sup −3} in the manganese ore mine; 2510(2341) Bq m{sup −3} and 3403(3075) Bq m{sup −3} in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m{sup −3} and 8512(1955) Bq m{sup −3} in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m{sup −3} and 161(148) Bq m{sup −3} in the bauxite mine; 187(191) Bq m{sup −3} and 117(147) Bq m{sup −3} in the manganese-ore mine; 360(524) Bq m{sup −3} and 371(789) Bq m{sup −3} in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m{sup −3} and 1462(3655) Bq m{sup −3} in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves

  15. Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

    International Nuclear Information System (INIS)

    Kávási, Norbert; Vigh, Tamás; Németh, Csaba; Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori

    2014-01-01

    During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C–21°C), low or high wind speed (max. 2.4 m s −1 ) and low or elevated aerosol concentration (130–60 000 particles m −3 ). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m −3 and 550(497) Bq m −3 in the bauxite mine; 887(604) Bq m −3 and 1258(788) Bq m −3 in the manganese ore mine; 2510(2341) Bq m −3 and 3403(3075) Bq m −3 in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m −3 and 8512(1955) Bq m −3 in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m −3 and 161(148) Bq m −3 in the bauxite mine; 187(191) Bq m −3 and 117(147) Bq m −3 in the manganese-ore mine; 360(524) Bq m −3 and 371(789) Bq m −3 in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m −3 and 1462(3655) Bq m −3 in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves. Consequently, correction is required on previously obtained radon data acquired by CF

  16. Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

    Science.gov (United States)

    Kávási, Norbert; Vigh, Tamás; Németh, Csaba; Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori

    2014-02-01

    During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C-21°C), low or high wind speed (max. 2.4 m s-1) and low or elevated aerosol concentration (130-60 000 particles m-3). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m-3 and 550(497) Bq m-3 in the bauxite mine; 887(604) Bq m-3 and 1258(788) Bq m-3 in the manganese ore mine; 2510(2341) Bq m-3 and 3403(3075) Bq m-3 in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m-3 and 8512(1955) Bq m-3 in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m-3 and 161(148) Bq m-3 in the bauxite mine; 187(191) Bq m-3 and 117(147) Bq m-3 in the manganese-ore mine; 360(524) Bq m-3 and 371(789) Bq m-3 in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m-3 and 1462(3655) Bq m-3 in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves. Consequently, correction is required on previously obtained radon data acquired by CF monitors at subsurface workplaces to gain comparable data for SF monitors. In the

  17. 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.

  18. Critical assessment of the deposition based dosimetric technique for radon/thoron decay products

    International Nuclear Information System (INIS)

    Mayya, Y.S.

    2010-01-01

    Inhalation doses due to radon ( 222 Rn) and thoron ( 220 Rn) are predominantly contributed by their decay products and not due to the gases themselves. Decay product measurements are being carried out essentially by either short-term active measurement like by air-sampling on a substrate followed by alpha or beta counting or by continuous active monitoring techniques based on silicon barrier detector. However, due to non-availability of satisfactory passive measurement techniques for the progeny species, it has been a usual practice to estimate the long time averaged progeny concentration from measured gas concentration using an assumed equilibrium factor. To be accurate, one is required to measure the equilibrium factor in situ along with the gas concentration. This being not practical, the assigned equilibrium factor (0.4 for indoor and 0.8 for outdoor for 222 Rn) approach has been an inevitable, though uncertain, part of the dosimetric strategies in both occupational and public domains. Further, in the case of thoron decay products however, equilibrium factor is of far more questionable validity. Thus, there is a need to shift from gas based dosimetric paradigm to that based on direct detection of progeny species

  19. Assessment of indoor radon, thoron concentrations, and their relationship with seasonal variation and geology of Udhampur district, Jammu & Kashmir, India.

    Science.gov (United States)

    Kumar, Ajay; Sharma, Sumit; Mehra, Rohit; Narang, Saurabh; Mishra, Rosaline

    2017-07-01

    Background The inhalation doses resulting from the exposure to radon, thoron, and their progeny are important quantities in estimating the radiation risk for epidemiological studies as the average global annual effective dose due to radon and its progeny is 1.3 mSv as compared to that of 2.4 mSv due to all other natural sources of ionizing radiation. Objectives The annual inhalation dose has been assessed with an aim of investigating the health risk to the inhabitants of the studied region. Methods Time integrated deposition based 222 Rn/ 220 Rn sensors have been used to measure concentrations in 146 dwellings of Udhampur district, Jammu and Kashmir. An active smart RnDuo monitor has also been used for comparison purposes. Results The range of indoor radon/thoron concentrations is found to vary from 11 to 58 Bqm -3 with an average value of 29 ± 9 Bqm -3 and from 25 to 185 Bqm -3 with an average value of 83 ± 32 Bqm -3 , respectively. About 10.7% dwellings have higher values than world average of 40 Bqm -3 prescribed by UNSCEAR. The relationship of indoor radon and thoron levels with different seasons, ventilation conditions, and different geological formations have been discussed. Conclusions The observed values of concentrations and average annual effective dose due to radon, thoron, and its progeny in the study area have been found to be below the recommended level of ICRP. The observed concentrations of 222 Rn and 220 Rn measured with active and passive techniques are found to be in good agreement.

  20. Developments of quad channel pulse height analyzer for radon/thoron measurement

    International Nuclear Information System (INIS)

    Ashokkumar, P.; Raman, Anand; Babu, D.A.R.; Sharma, D.N.; Topkar, Anita; Mayya, Y.S.

    2011-01-01

    Radon and thoron are naturally occurring noble radioactive gases, the exposure to which has a linear relationship to lung cancer risk. This paper describes development of an automated Radon/Thoron measurement system using an indigenously developed silicon PIN diode. This system employs the 8051 core architecture based Si-lab microcontroller (C-8051F340) integrated with LCD display, hex key pad, non volatile flash memory besides I/O ports interfaced with humidity-temperature sensors and air sampling pump. Air is sampled through a dehumidifier by using a software controlled dc pump. The positively charged progeny atoms are electro statically collected over the detector surface and the deposited radioactivity is assessed by alpha pulse height discrimination technique. The ionization charges produced due to the interaction of alpha particles in the charge depletion region of the diode which is reverse biased at 40V are collected and measured. The measurement circuit uses a charge sensitive preamplifier developed around a low noise opamp IC. The pulses are further processed through a spectroscopy amplifier to obtain distinct pulse height levels for four of the alpha emitting progenies of Rn and Tn namely 210 Po, 214 Po, 216 Po and 212 Po. These signals are input to the quad channel analyzer which provides four individual TTL pulses corresponding to four nuclides mentioned above. The analyzer outputs are processed by the microcontroller module to obtain the Rn/Tn concentration in Bq/M 3 . This portable system stores one week hourly individual channel data along with the corresponding Rn/Tn concentrations, temperature, humidity and can be transferred to pc. Preliminary studies have indicated that sensitivity as low as 0.50 cph/Bq.m -3 can be achieved by this system. (author)

  1. The effect of time-dependent ventilation and radon (thoron) gas emanation rates in underground uranium mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1987-01-01

    A theoretical radiation mine model, suitable for underground uranium mines, has been investigated. In this model, the rate of ventilation and/or the radon (thoron) gas emanation from mine walls are time-dependent. Several cases of practical interest have been investigated including sinusoidal, linear, exponential, stepwise, or a combination of two or more of the above. Analytical solutions were obtained for the time-dependent radon (thoron) gas emanation rate. However, because of the extreme analytical complexity of the solutions corresponding to the time-dependent ventilation rate case, numerical solutions were found using a special Runge-Kutta procedure and the Hamming's modified predictor-corrector method for the solution of linear initial-value problems. The mine model makes provisions for losses of radioactivity, other than by ventilation and radioactive decay, by, say, plate-out on mine walls, and by other mechanisms. Radioactivity data, i.e., radon, thoron, and their progeny, obtained with the above mine model for a number of ventilation and emanation conditions, are presented. Experimental data obtained in an inactive stope of an underground uranium mine for a time-dependent air flow case are shown. Air flow conditions (ventilation rate) were determined by tracer gas techniques using SF 6

  2. Thoron measurements in Hungary

    International Nuclear Information System (INIS)

    Kovacs, T.

    2010-01-01

    In this study, several Hungarian dwellings and working places were surveyed using passive radon- and thoron-measuring devices (Radopot R and Raduet R from 2003 to 2008. The detectors were placed 15-30 cm from the wall throughout the 1-to 3-month period. In dwellings, the presence of thoron, ∼100 Bq m -3 , was detected almost in all cases; however, in the cellars of these buildings, a value ∼200 Bq m -3 was typical. In the cases of manganese and bauxite mines, the concentration of thoron was mainly 200 and 500 Bq m -3 , respectively. In caves, it was 1000 Bq m -3 , whereas in the radon bath it was ∼100 Bq m -3 . As in many cases, the ratio between thoron and radon concentrations was > 0.25 and the dose contribution from thoron and its progeny was not negligible. Therefore, further investigation on the thoron progeny will be necessary for an accurate dose estimation. (authors)

  3. Study of indoor radon, thoron and their progeny concentration levels in the surrounding areas of Mangaldoi, Assam

    International Nuclear Information System (INIS)

    Deka, P.C.; Sarkar, S.; Goswami, T.D.; Sarma, B.K.

    2006-01-01

    Natural sources contribute a significant percentage of radiation towards the total radiation exposure that humans receive. The majority of this natural radiation is harmless to humans in the ambient environment. However, radon, a major component of the natural radiation that humans are exposed to (greater than sixty percent), can pose a threat to the public health when radon gas accumulates in poorly ventilated residential and occupational settings. Measurements of concentration of radon, thoron and their decay products in various indoor environment covering four seasons of a year were carried out using the passive time-integrated method by employing LR-15 type II detectors in plastic twin-chamber dosimeter cups. The estimated indoor radon levels for well ventilated houses varied from a minimum value of 25.2 Bq.m -3 to a maximum of 80J Bq.m -3 with an annual geometric mean of 46.9 Bq.m -3 and that for poorly ventilated houses varied from a minimum value of 46.8 Bq.m -3 to a maximum of 146.8 Bq.m -3 with the annual geometric mean of 82 .2 Bq.m -3 . The thoron levels in well ventilated houses were also varied from a minimum value of 4.9 Bq.m -3 to a maximum of 21.5 Bq.m -3 with an annual geometric mean of 10.5 Bq.m -3 and that for poorly ventilated houses varied from a minimum of 6.3 Bq.m -3 to a maximum value of 29.2 Bq.m -3 with the annual geometric mean of 14.1 Bq.m -3 . Thus it is seen that both radon and thoron levels are higher in poorly ventilated houses than in well-ventilated houses. The ranges of radon and thoron progeny levels for well ventilated houses were 0.10 mWL to 0.58 mWL with an annual geometric mean of 0.21 mWL and 0.01 mWL to 0.06 mWL with an annual geometric mean of 0.03 mWL respectively. Similar variation was also observed in poorly ventilated houses. In poorly ventilated houses, the radon and thoron progeny levels varied between 0.16 mWL and 1.61 mWL with an annual geometric mean of 0.41 mWL and 0.02 to 029 mWL with the annual geometric mean

  4. Indoor inhalation dose estimates due to radon and thoron in some areas of South-Western Punjab (India))

    International Nuclear Information System (INIS)

    Kumar, S.; Singh, S.; Bajwa, B. S.; Singh, B.; Sabharwal, A. D.; Eappen, K. P.

    2008-01-01

    LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for estimating radon 222 Rn) and thoron 220 Rn) concentrations in dwellings of south-western Punjab (India)). The present study region has shown pronounced cases of cancer incidents in the public [Thakur, Rao, Rajwanshi, Parwana and Kumar (Epidemiological study of high cancer among rural agricultural community of Punjab in Northern India. Int J Environ Res Public Health 2008; 5(5):399-407) and Kumar et al. (Risk assessment for natural uranium in subsurface water of Punjab state (India)). Hum Ecol Risk Assess 2011;17:381-93)]. Radon being a carcinogen has been monitored in some dwellings selected randomly in the study area. Results show that the values of radon 222 Rn) varied from 21 to 79 Bq m -3 , with a geometric mean of 45 Bq m -3 [geometric standard deviation (GSD 1.39)], and those of thoron 220 Rn) from minimum detection level to 58 Bq m -3 with a geometric mean of 19 Bq m -3 (GSD 1.88). Bare card data are used for computing the progeny concentration by deriving the equilibrium factor (F) using a root finding method [Mayya, Eappen and Nambi (Methodology for mixed field inhalation dosimetry in monazite areas using a twin-cup dosemeter with three track detectors. Radiat Prot Dosim 1998; 77(3): 177-84)]. Inhalation doses have been calculated and compared using UNSCEAR equilibrium factors and by using the calculated F-values. The results show satisfactory comparison between the values. (authors)

  5. Study on radon and thoron levels in different types of dwellings of Lambapur area of Nalgonda District, A.P., India

    International Nuclear Information System (INIS)

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

    2006-01-01

    An attempt has been made to study the indoor radon and thoron concentration levels in different types of dwellings of Lambapur and Peddagattu proposed uranium mining areas. The dwellings with mud floors recorded a relatively higher concentrations compared to those with other type of floors. Similar studies have also been made with different types of walls. In this case, dwellings having brick walls with mud plastering showed relatively higher levels of radon and thoron concentrations. The average concentration levels of radon and thoron in this area is found to be 88.8 ± 66.7 Bq.m -3 and 118.3 ± 96.4 Bq.m -3 . (author)

  6. Studies on the diffusional and electrical transport of the daughter aerosols of radon and thoron in moving gases

    International Nuclear Information System (INIS)

    Mayya, Y.S.; Sahni, D.C.

    1994-01-01

    This report presents a detailed theoretical study of the transport characteristics of the daughter products of radon and thoron gases in channel flow devices. Specific aspects examined include: (i) development of the Green's function of the convective-diffusion operator and its boundary layer forms with and without axial diffusion, (ii) transport probabilities of recoil atoms (RaB) emitted into stagnant and moving gases, due to alpha decays of the parent atoms (RaA) deposited on surfaces, (iii) a comprehensive theory of double filter systems and (iv) microscopic theory of particle transport in moving fluids based on the Fokker-Planck equation. Both uniform and parabolic velocity profiles are considered. Various applications of the solutions in interpreting the measured data are presented. Chief among them is the application of the advanced theory of double-filter systems employed in Trombay studies for the measurements of thoron in the exhaled breath of thorium workers. (author). 130 refs., 4 figs

  7. Dose assessment from exposure to radon, thoron and their progeny concentrations in the dwellings of sub-mountainous region of Jammu and Kashmir, India

    International Nuclear Information System (INIS)

    Kaur, M.; Dr. B. R. Ambedkar National Institute of Technology, Jalandhar, Punjab; Kumar, A.; Mehra, R.; Mishra, R.

    2018-01-01

    The present work deals with the assessment of annual inhalation dose due to exposure of indoor radon, thoron and their progeny concentrations in the villages situated in sub-mountainous region of Jammu and Kashmir, India. The distribution of the data and the homogeneity of medians among different seasons and dwellings were assessed with the Shapiro-Wilk test and the Mann-Whitney test. The estimated total annual inhalation dose in these villages varied from 0.5 to 1.9 mSv year -1 which is less than the prescribed limit by ICRP (2008). Thus, the investigated area is safe from irradiation of radon, thoron and their progeny. (author)

  8. Experimental technique to measure thoron generation rate of building material samples using RAD7 detector

    International Nuclear Information System (INIS)

    Csige, I.; Szabó, Zs.; Szabó, Cs.

    2013-01-01

    Thoron ( 220 Rn) is the second most abundant radon isotope in our living environment. In some dwellings it is present in significant amount which calls for its identification and remediation. Indoor thoron originates mainly from building materials. In this work we have developed and tested an experimental technique to measure thoron generation rate in building material samples using RAD7 radon-thoron detector. The mathematical model of the measurement technique provides the thoron concentration response of RAD7 as a function of the sample thickness. For experimental validation of the technique an adobe building material sample was selected for measuring the thoron concentration at nineteen different sample thicknesses. Fitting the parameters of the model to the measurement results, both the generation rate and the diffusion length of thoron was estimated. We have also determined the optimal sample thickness for estimating the thoron generation rate from a single measurement. -- Highlights: • RAD7 is used for the determination of thoron generation rate (emanation). • The described model takes into account the thoron decay and attenuation. • The model describes well the experimental results. • A single point measurement method is offered at a determined sample thickness

  9. Study of radiation exposure due to radon, thoron and progeny in the indoor environment of Yamuna and Tons valleys of Garhwal Himalaya

    International Nuclear Information System (INIS)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Ramola, R.C.; Prasad, Ganesh; Mishra, Rosaline

    2016-01-01

    Long-term measurements of indoor radon, thoron and their progeny concentrations have been carried out in dwellings of Yamuna and Tons Valleys of Uttarkashi, Garhwal Himalaya to investigate the health risk associated with inhalation of radon, thoron and progeny. The experimentally determined values of radon, thoron and progeny concentrations were used to estimate the annual inhalation doses and annual effective doses. The annual inhalation dose has been found to vary from 0.8 to 3.9 mSv y -1 with an average of 1.8 mSv y -1 . The annual effective dose from the exposure to radon and its progeny in the study area has been found to vary from 0.1 to 2.4 mSv with an average of 1.2±0.6 mSv. Similarly, the annual effective dose due to thoron and its progeny has been found to vary from 0.2 to 1.5 mSv with an average of 0.6±0.4. The measurement techniques and results obtained are discussed in detail. (authors)

  10. STUDY OF RADIATION EXPOSURE DUE TO RADON, THORON AND PROGENY IN THE INDOOR ENVIRONMENT OF YAMUNA AND TONS VALLEYS OF GARHWAL HIMALAYA.

    Science.gov (United States)

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Prasad, Ganesh; Mishra, Rosaline; Ramola, R C

    2016-10-01

    Long-term measurements of indoor radon, thoron and their progeny concentrations have been carried out in dwellings of Yamuna and Tons Valleys of Uttarkashi, Garhwal Himalaya to investigate the health risk associated with inhalation of radon, thoron and progeny. The experimentally determined values of radon, thoron and progeny concentrations were used to estimate the annual inhalation doses and annual effective doses. The annual inhalation dose has been found to vary from 0.8 to 3.9 mSv y -1 with an average of 1.8 mSv y -1 The annual effective dose from the exposure to radon and its progeny in the study area has been found to vary from 0.1 to 2.4 mSv with an average of 1.2±0.6 mSv. Similarly, the annual effective dose due to thoron and its progeny has been found to vary from 0.2 to 1.5 mSv with an average of 0.6±0.4. The measurement techniques and results obtained are discussed in detail. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Determination of the characteristic limits and responses of nuclear track detectors in mixed radon and thoron atmospheres

    International Nuclear Information System (INIS)

    Röttger, Annette; Honig, Anja; Schrammel, Dieter; Strauss, Heinrich F.

    2016-01-01

    Closed nuclear track detectors are widely used for the determination of Rn-222 exposures. There are also partial open systems available, which are specially designed for the determination of the exposure to Rn-220, which is a relevant exposure in special workplaces or in specific regions of the world. This paper presents data and a detail analysis of how to determine the cross-correlation by calibration in pure Rn-222 and pure Rn-220 atm. By these means calibration coefficients for the analysis of real mixed atmospheres can be obtained. The respective decision threshold, detection limit and limits of the confidence interval were determined according to ISO 11929 (ISO 11929:2010, 2010). The exposure of detectors was performed at the radon reference chamber and the thoron progeny chamber of the Physikalisch-Technische Bundesanstalt (PTB). The analysis of track response was done at Parc RGM, while the analytical routines were developed in the Leibniz University Hanover, Institute Radioökologie und Strahlenschutz IRS at the working Group AK SIGMA (Arbeitskreis Nachweisgrenzen). - Highlights: • Analysis of exposure in reference atmospheres according ISO 11929. • Calibration of nuclear track detectors for 222 Rn and 220 Rn. • Calculation of cross-correlation by calibration in pure 222 Rn and 220 Rn atmospheres. • Thoron activity concentration should not be omitted in radon exposure determinations.

  12. Investigation on the movements and the distributions of radon, thoron and their decay nuclides on the life circumstances

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko

    2001-03-01

    UNSCEAR (2000) reported that the effective doses due to the inhalation of radon and its decay nuclides account on average of the all world for about one-half of all natural sources of radiation. These have great influences on various forms as the sources of terrecial environmental γ radiation and of radon on our life circumstances. Radon and thoron, which are natural gaseous radioactive nuclides released out of rocks and soil etc. are chemical inert and electrically uncharged, but they in the air can spontaneously decay to other metal atoms. And they made a wide fluctuation seasonally and spatially on the environment, but these are not uniformly. We have selected and observed on Misasa spa district, Tottori pref., Kawanishi-shi, Hyogo pref. and Masutomi spa, Yamanashi pref., for HBRA, and Higashi-osaka-shi, Osaka pref., for CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon, thoron and their decay nuclides, and reported these results on following; (1) Radon measurements have been carried using a small pico-rad detector and many sampling points and Pilon scintillation-cell with 300 ml volume by grub sampling. Mean radon concentrations of get briefly for 24 hours are measured to be available on draw of the concentration distribution map. (2) We continued time cource variation of mean radon concentrations on same private house of Misasa spa district. Mean radon concentrations in air for 6 years were fluctuated 6.7-50 Bq/m 3 and 23-170 Bq/m 3 indoor. The mean concentrations on summer and rain season is low level at open-door situation and that on winter is high, as same as these on Kawanishi Hyogo pref.. It was shown that radon outdoor concentrations variation in time course almost have a similar tendency with indoor and the life situation of air ventilation and conditioning are more influenced than variation on area condition. (3) Radon concentrations on Masutomi spa districts, Yamanashi

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  14. Measurement of indoor radon-thoron and their progeny levels in dwellings and radon concentrations in ground water of Hassan city, Karnataka, India

    International Nuclear Information System (INIS)

    Srinivasa, E.; Rangaswamy, D.R.; Sannappa, J.

    2014-01-01

    The indoor radon and thoron concentrations in dwellings of Hassan city have been measured by using LR-115 type-Il Solid State Nuclear Tracks Detectors (SSNTDs). Measurements were carried in summer season from March to May-2013. The radon and thoron activity concentration in the corresponding dwellings has been found to vary from 7.4 to 45.7 Bqm -3 and 5.4 to 34.9 Bqm -3 with a median of 23.59±11 Bqm -3 and 14.47±8 Bqm -3 respectively. The overall average radon concentrations are found to be less than the lower reference level of 200 Bq m -3 of the International Commission on Radiological Protection. The annual effective dose received due to radon and its progeny by the inhabitants in the dwellings under study has also been calculated which found to vary from 0.320 ±0.4 to 1.86 ±1.1 mSv y -1 with an average value of 0.957±0.8 mSv -1 . The obtained results are much lower than the upper reference level of 10 mSv y -1 (ICRP 2007). Radon in bore well water at different locations of Hassan city was determined using the emanometry technique and exposure dose from ingestion of drinking water was estimated. The radon concentration in ground water was found to vary from 19.49 to 60.74 Bq l -1 with an average value of 47.16±14Bq l -1 . From this study it is evident that, the recorded ground water radon concentration values are higher than MCL of 11 Bq l -1 proposed by USEPA. The total dose due to inhalation and ingestion of 222 Rn in ground water ranges from 0.053 mSv y -1 to 0.165mSv y -1 with an average value of 0.127±0.038mSv y -1 . (author)

  15. Evaluation of thoron-daughter instruments

    International Nuclear Information System (INIS)

    George, J.L.

    1992-09-01

    Several DOE decontamination and decommissioning sites need to accurately measure thoron-daughter concentrations during decontamination efforts. Because the workers at these sites receive their dose from thoron-daughters rather than thoron gas, the thoron-daughter concentration is the measurement of interest. Some instruments currently used for making radon-daughter concentration measurements also claim the ability to measure thoron-daughter concentrations. This study evaluated the validity of those claims

  16. 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

  17. Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

    Science.gov (United States)

    Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Uranium, RADON and radon isotopes in selected brines of Poland

    International Nuclear Information System (INIS)

    Kozlowska, B.; Walencik, A.; Zipper, W.; Dorda, J.; Przylibski, T.A.

    2010-01-01

    Natural radioactive isotopes were studied in nine different types of brines from four locations in Poland. Investigated brines are exploited from various geological structures composed of the rocks of different chemical and mineral composition as well as different age and depth. All investigated brines are used in balneotherapy (i.e. baths, inhalations, showers). The main goal of this study was to obtain some basic knowledge on the activity range of natural elements such as uranium, RADON and radon in different brine types in Poland and their variability depending on their location in certain geological structures. Activities of 234,238 U, 226,228 Ra and 222 Rn isotopes were measured with the use of two nuclear spectrometry techniques: liquid scintillation and alpha spectrometry. The activity concentrations of 222 Rn vary from below 1 to 76.1±3.7 Bq/l, for the 226 Ra isotope from 0.19±0.01 to 85.5±0.4 Bq/l and for 228 Ra from below 0.03 to 2.17±0.09 Bq/l. For uranium isotopes, the concentrations are in the range from below 0.5 to 5.1±0.4 mBq/l for 238 U and from 1.6±0.4 to 45.6±2.0 mBq/l for 2 34U . The obtained results indicate high RADON activity concentrations corresponding to high mineralization of waters. (authors)

  19. Investigation of radon, thoron, and their progeny near the earth's surface. Final report, 1 January 1994 - 31 December 1997

    International Nuclear Information System (INIS)

    Schery, S.D.; Wasiolek, P.T.

    1998-01-01

    This is the final report for DOE Grant DE-FG03-94ER6178, covering a performance period of 1 January 1994 through 31 December 1997. The DOE award amount for this period was $547,495. The objective of the project as stated in its proposal was open-quotes to improve our understanding of the physical processes controlling the concentration of radon, thoron, and their progeny in the atmospheric environment.close quotes The original project was directed at developing underlying science that would help with evaluation of the health hazard from indoor radon in the United States and implementation of corrective measures that might be employed to reduce the health hazard. As priorities within the Office of Health and Environment (OHER) changed, and the radon research program was phased out, emphasis of the project was shifted somewhat to be also relevant to other interests of the OHER, namely global pollution and climate change and pollution resulting from energy production. This final report is brief, since by reference it can direct the reader to the comprehensive research publications that have been generated by the project. In section 2, we summarize the main accomplishments of the project and reference the primary publications. There were seven students who received support from the project and their names are listed in section 3. One of these students (Fred Yarger, Ph.D. candidate) continues to work on research initiated through this project. No post-docs received support from the project, although one of the co-principal investigators (Dr. Piotr Wasiolek) received the majority of his salary from the project. The project also provided part-time support for a laboratory manager (Dr. Maryla Wasiolek). Section 4 lists chronologically the reports and publications resulting from the project (references 1 through 12), and the Appendix provides abstracts of major publications and reports

  20. Asian/Australasian region intercalibration and intercomparison programme for radon, thoron and daughters. Asian/Australasian region radon intercomparison, September 1987 - September 1988

    Energy Technology Data Exchange (ETDEWEB)

    Peggie, J.R.; Gan, Tianghong; Solomon, S.B.

    1993-05-01

    The International Intercalibration and Intercomparison Programme for radon, thoron and daughters monitoring equipment, abbreviated IIIP, was a programme organized jointly by the Nuclear Energy Agency of the Organization for Economic Cooperation and Development and the Radiation Protection Research Programme of the Commission of European Communities. The broad purpose of the IIIP was to determine if the diverse calibration procedures used in different countries were equivalent. The general approach was to select four regional reference laboratories and entrust then with the details of project definition and execution. The Australian Radiation Laboratory (ARL) was selected to co-ordinate IIIP activities between OECD member countries in the Pacific region. As the regional programme precluded the participation of non-OECD member countries in the Western Pacific Region, an intercomparison series for radon was initiated by ARL in 1987 between twenty eight laboratories from nine countries in the Asian/Australasian region. The methodology and protocols for grab sampler, solid state nuclear track detectors (SSNTD) and charcoal measurements are described in this report. Generally the results showed reasonable agreement between the majority of laboratories for grab sampler measurements consistent with previous intercomparison. However there were large systematic differences in the results of the passive monitors for some laboratories. For all samplers, it was found that the overall random uncertainty or replication error, which included random uncertainties associated with the counting and calibration, were the main sources of variability between individual measurements of participants and the ARL reference value, with calibration uncertainties predominating. 23 tabs.

  1. Asian/Australasian region intercalibration and intercomparison programme for radon, thoron and daughters. Asian/Australasian region radon intercomparison, September 1987 - September 1988

    International Nuclear Information System (INIS)

    Peggie, J.R.; Gan, Tianghong; Solomon, S.B.

    1993-05-01

    The International Intercalibration and Intercomparison Programme for radon, thoron and daughters monitoring equipment, abbreviated IIIP, was a programme organized jointly by the Nuclear Energy Agency of the Organization for Economic Cooperation and Development and the Radiation Protection Research Programme of the Commission of European Communities. The broad purpose of the IIIP was to determine if the diverse calibration procedures used in different countries were equivalent. The general approach was to select four regional reference laboratories and entrust then with the details of project definition and execution. The Australian Radiation Laboratory (ARL) was selected to co-ordinate IIIP activities between OECD member countries in the Pacific region. As the regional programme precluded the participation of non-OECD member countries in the Western Pacific Region, an intercomparison series for radon was initiated by ARL in 1987 between twenty eight laboratories from nine countries in the Asian/Australasian region. The methodology and protocols for grab sampler, solid state nuclear track detectors (SSNTD) and charcoal measurements are described in this report. Generally the results showed reasonable agreement between the majority of laboratories for grab sampler measurements consistent with previous intercomparison. However there were large systematic differences in the results of the passive monitors for some laboratories. For all samplers, it was found that the overall random uncertainty or replication error, which included random uncertainties associated with the counting and calibration, were the main sources of variability between individual measurements of participants and the ARL reference value, with calibration uncertainties predominating. 23 tabs

  2. The determination of airborne concentrations of radon and thoron progeny by repetitive alpha counting of filter samples

    International Nuclear Information System (INIS)

    French, Clayton S. Jr.; Skrable, Kenneth W.; Chabot, George E.

    1978-01-01

    Analytical equations have been used to determine the airborne concentrations of the particulate daughters of radon and thoron from five net alpha counts obtained at preset time intervals post sampling. The same expressions were used to propagate the associated standard deviations. These propagated errors were minimized by the selection of optimum sampling and counting intervals. An extensive error analysis examined sources of interference and their influence on the calculated concentrations. This system offers sufficient precision for research applications, yet is simple and inexpensive enough for application in field studies. The radon and thoron daughters measured with this technique are 218 Po, 214 Pb, 214 Bi, 212 Pb, and 212 Bi. Because of the decay kinetics involved, the calculated concentrations of 218 Po and 212 Bi involve the greatest uncertainty. The proper choice of sampling and counting intervals optimizes the system for any one of the above radionuclides or for all five collectively. A sampling time of 15 minutes is best for the simultaneous estimation of all five concentrations. Millipore filter samples were obtained from a large, unventilated sub-basement of the University of Lowell research reactor facility and were counted later in direct contact with the window of a gas flow proportional detector having alpha particle counting efficiencies near 0.4 ca -1 and an alpha background of about 1 c min -1 . A typical 15 minute sample obtained at a flow rate of 2 x 10 4 cm 3 min -1 yielded estimates of the airborne concentrations and relative standard deviations: 218 Po, 4.75 x 10 -9 μCi cm -3 ± 18.9%; 214 Pb, 5.15 x 10 -9 μCi cm -3 ± 2.5%; 214 Bi, 4.86 x 10 -9 μCi cm -3 ± 2.4%; 212 Pb, 1.41 x 10 -10 μCi cm -3 ± 2.0%; and 212 Bi, 2.15 x 10 -10 μCi cm -3 ± 27.0%. (author)

  3. A radon (thoron) daughter personal alpha-dosimeter of the passive type using a diffused-junction detector and an electrostatic collector

    International Nuclear Information System (INIS)

    Bigu, J.; Frattini, A.

    1984-05-01

    A solid-state alpha-dosimeter has been designed and found to be suitable for personal and environmental radon-thoron daughter monitoring. The dosimeter basically consists of an electrostatic collector and an alpha-particle counting system with spectroscopy capabilities. The sensitive volume (∼20 cm 3 ) of the electrostatic collector consists of a cylindrically-shaped metal wire screen and a diffused-junction silicon alpha-detector covered with a thin aluminized mylar sheet. A DC voltage (∼450 V) is applied between the wire screen and the mylar sheet, the latter held at negative potential relative to the metal screen. Data can be retrieved during or after sampling by means of a micro-computer (Epson HX20) via a RS-232 communcation interface unit. The dosimeter has been calibrated in a large (26 m 3 ) radon/thoron test facility. A linear relationship was found between radon gas concentration and radon daughter Working Level, and the dosimeter's alpha-count. The dosimeter is mounted on top of an ordinary miner's cap lamp battery and is ideally suited for personal monitoring in underground uranium mines and other working areas. The dosimeter presented here is a considerably improved version of an earlier prototype

  4. Radon and thoron daughter activities in the environment of the King George Island (West Antarctica

    Directory of Open Access Journals (Sweden)

    A. T. Solecki

    2005-06-01

    Full Text Available Results of 253 gamma spectrometric analyses of radon daughters in soil and bedrocks of the King George Island (West Antarctica are presented. Measured values range from 0.1 to 58.4 Bq/kg, and from 4.9 to 75.5 Bq/kg for 214Bi and 208Tl respectively, but most measurements fall in the lower part of this range due to predominantly basaltic character of the geological basement. Obtained gamma spectrometric data correspond well to very low soil gas radon content measured by means of Kodak LR115 being below 454 Bqm-3. Low soil gas radon content and characteristic type of architecture is responsible for low indoor radon activity in Arctowski Station being as low as 10- 15 Bqm-3. The highest 105 Bqm-3 indoor Rn activity has been measured in the greenhouse bungalow of the station. This increased value was probably connected with the presence of about 1000 kg of imported soil material in the greenhouse room of the bungalow. Local zones of increased uranium and thorium content, discovered as a result of radiometric mapping, can potentaily influence atmospheric radon used for meteorological interpretation.

  5. AGE-DEPENDENT INHALATION DOSE DUE TO EXPOSURE OF SHORT LIVED PROGENY OF RADON AND THORON FOR DIFFERENT AGE GROUPS IN JAMMU & KASHMIR, HIMALAYAS.

    Science.gov (United States)

    Sharma, Sumit; Kumar, Ajay; Mehra, Rohit

    2018-05-16

    Dosimetric approach is used in this study for the assessment of doses due to inhalation of short lived radon/thoron progeny to the inhabitants of Udhampur district of Jammu & Kashmir. This paper also presents the activity concentrations and unattached fraction of radon and thoron progeny. The observed annual concentration of attached and unattached 222Rn and 220Rn progeny has been found to vary from 8 to 32 and 0.09 to 14 Bq/m3, 0.75 to 3.16 and 0.01 to 1.13 Bq/m3, respectively. The inhalation doses from radon progeny to different body organs of different age groups have been calculated by using the age dependent biokinetic model. The attachment rate of 222Rn and indoor aerosol concentration of 222Rn and 220Rn have been estimated and their relation between them has also been studied. The dose conversion factor for mouth and nasal breathing to different exposure conditions has been obtained from Porstendorfer model.

  6. The effect of RTP (Radon Thoron Progeny) and dust loading on the design of an alarm system for airborne plutonium particulates

    International Nuclear Information System (INIS)

    Pai, H.L.; Sun, L.C.

    2004-01-01

    If the alpha method is adopted, the main problem for determining airborne plutonium particulates is the overlapping of the alpha spectrum between Pu and RTF (radon thoron progeny). The order of magnitude estimation establishes that RTP is more than 20 times higher than Pu. Therefore a method of discriminating RTP is required. The primary methods of discrimination are the aerosol size and the alpha spectrum methods. If the alpha spectrum method is adopted, the formation of the low energy tail of RTP should be investigated. Preliminary study indicates that the low energy tail is related to the air gap and dust loading. (author)

  7. Analysis of errors in the measurement of unattached fractions of radon and thoron progeny in a Canadian uranium mine using wire screen methods

    International Nuclear Information System (INIS)

    Khan, A.; Phillips, C.R.

    1987-01-01

    The unattached fraction of radon/thoron progeny in uranium mines is generally small and therefore difficult to measure accurately. The simple wire screen method provides a direct estimate of the unattached fraction from the screen count, or an indirect estimate from the difference between the reference and back-up filter counts. Wire screen method results are often difficult to analyse, especially when the unattached activity is small. Experimental data obtained in Canadian uranium mines are presented here, together with a detailed error analysis. The method consisting of counting the wire screen and the back-up filter is found to be the most precise method for unattached fraction determination. (author)

  8. Comments upon 'basis of intake limits for radon and thoron daughters'

    International Nuclear Information System (INIS)

    Stewart, C.G.

    1984-05-01

    AECB consultative document C-78 proposes that the different types of exposure in uranium mines should be combined in such a fashion that the sum of the fractions contributing to annual dose (each fraction being the annual exposure of each type divided by the corresponding maximum permissible annual exposure) does not exceed unity. In order for this approach to be valid it is necessary for each of the demoninators to represent the same risk of mortality from malignancy, in this instance mortality from lung cancer where malignancy and mortality are very nearly equal. Document C-78 indicates that the limit of 50 mSv/a for whole body gamma irradiation and 4.7 WLM/a exposure to radon daughters are assumed to carry the same risk of mortality from malignancy. In the following document it is demonstrated that this assumption is not valid and consequently the current recommendations of C-78 for combining risk from gamma radiation and radon daughters are also not tenable

  9. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    Energy Technology Data Exchange (ETDEWEB)

    Bigu, J [Department of Energy, Mines and Resources, Elliot Lake, Ontario (Canada). Elliot Lake Lab.; Raz, R; Golden, K; Dominguez, P [Alpha-NUCLEAR, Toronto, Ontario (Canada)

    1984-08-15

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operation with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross ..cap alpha..-count methods and ..cap alpha..-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of ..cap alpha..-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software.

  10. Probing the application of Fourier Transform Infrared (FTIR) spectroscopy for assessment of deposited flux of Radon and Thoron progeny in high exposure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, R., E-mail: rosaline@barc.gov.in; Sapra, B.K.; Rout, R.P.; Prajith, R.

    2016-12-01

    Direct measurement of Radon and Thoron progeny in the atmosphere and occupational environments such as Uranium mines, Uranium and Thorium handling facilities has gained importance because of its radiological significance in inhalation dose assessment. In this regard, Radon and Thoron Progeny sensors (DTPS and DRPS) are the only passive solid state nuclear track detector (SSNTD, LR115) based devices which are being extensively used for time integrated direct progeny measurements. An essential component of the analysis is the chemical etching of the detectors, followed by spark counting of tracks and then estimation of the inhalation dose using appropriate calibration factors. Alternatively, the tracks may be counted using image analysis techniques. However, under high exposure conditions, both these methods have inherent limitations and errors arising due to increased frequency of tracks. In the present work, we probe the use of Fourier Transform Infra Red (FTIR) spectroscopy to analyse the deposited fluence of the progeny particulates based on change in transmittance of the nitric group vibrational bands of the LR115. A linear relationship between the transmittance and the deposited fluence was observed, which can be used to estimate the deposited fluence rate and the inhalation dose. This alternative method of analysis will provide a faster and non-destructive technique for inhalation dose assessment, specially for routine large scale measurements. - Highlights: • An alternative method of inhalation dose assessment. • Linearity between the transmittance of nitric goup bands and the deposited fluence. • Faster and non-destructive technique for high exposure scenarios.

  11. Baseline studies of radon/thoron concentration levels in and around the Lambapur and Peddagattu areas in Nalgonda district, Andhra Pradesh, India

    International Nuclear Information System (INIS)

    Vinay Kumar Reddy, K.; Sreenivasa Reddy, B.; Sreenath Reddy, M.; Gopal Reddy, Ch.; Yadagiri Reddy, P.; Rama Reddy, K.

    2003-01-01

    Studies conducted by Atomic Minerals Directorate of Exploration and Research (AMD) of Hyderabad, India had established the presence of higher concentrations of uranium in Lambapur and Peddagattu areas of Nalgonda district, AP, India and it was estimated that it could be a viable source for commercial extraction. The envisaged extraction process involves dispersion of radioactive particulate matter into atmosphere. Environmental radioactive studies in and around proposed mining areas at this point of time will be extremely useful for establishing base line data before a large scale uranium extraction process comes into existence. To this end, Solid State Nuclear Track Detectors were installed to evaluate indoor radon and thoron concentration levels in the dwellings of the area. The geometric means of radon and thoron concentration levels were found to be (7.1±0.2)x10 1 and (6.7±0.3)x10 1 Bq/m 3 , respectively. Simultaneously, natural background radiation measurements were also made and these levels are found to vary from 770 to 3995 μGy/y in the spatial distribution

  12. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    International Nuclear Information System (INIS)

    Bigu, J.

    1984-01-01

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operatin with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross α-count methods and α-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of α-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software. (orig.)

  13. Study of radon and thoron gas behaviour in the air at the commercial centers in Rio de Janeiro and Pocos de Caldas city; Estudo do comportamento dos gases radonio e toronio presentes no ar em centro comercial do Rio de Janeiro e Pocos de Caldas

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Carlos A.C. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica. Lab. de Robotica, Soldagem e Simulacao; Morales, Rudnei K; Santos, Victor C. dos . [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); br, victorcs@ime eb; Cardoso, Domingos D [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The radon is a radioactive gas. It occurs naturally in the atmosphere coming from the decay of radium, with emission of alpha particles. There are three radon isotopes more known, of which the most important under the environmental point of view is the Rn-222, whose half life is 3.82 days. The radon and their descendants are responsible by more than 40 % of the natural radioactive dose received for the human beings inside the building. In doses above 4 pCi/l, given as occupational dose, can cause among other diseases, the lung cancer. The main source of radon inside the building is the soil. The incidence of radon inside the building varies according to the soil composition, the materials employed in its construction, the inside air temperature and humidity, time during the day, season and the ventilation process designed. The work was realized at the commercial centers in Rio de Janeiro and Pocos de Caldas, for methodology confirmation. It was utilized the passive (track detectors) and active (two filters technique. Kusnetz technique, Tsivoglou technique and alpha spectrometry technique) methods. The objective of this work was to analyze the radon and thoron concentrations levels in order to supply parameters upon the quality of the air in those commercial centers. (author)

  14. The influence of the soil and plant natures and pollution on the radon and thoron alpha-activities inside various herbal infusions by using solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Nouh, F.A.; Bourzik, W.

    2001-01-01

    Uranium and thorium contents were determined in samples of various plants in the soils in which the plants were grown, and in herbal infusions made by boiling the plants in potable water, using CR-39 and LR-115 solid state nuclear track detectors. In addition, radon and thoron alpha-activities per unit volume inside the plants, soils and herbal infusions were measured. These measurements were completed by an investigation of the radon transfer between soils and plants and that between plants and herbal infusions, and also by the investigation of the influence of pollution due to different material dusts on the radon and thoron alpha activities inside the plants and their infusions. (author)

  15. Study of the influence of the soil and plant natures and pollution on the radon and thoron alpha activities inside various herbal infusions by using solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Ait nouh, F.; Bourzik, W.; Lamine, J.

    2000-01-01

    Different medicinal plant, spinach and cereal samples have been analysed by using neutron activation analysis and radiochemical separation. The solid state nuclear track detectors technique was utilized for uranium and thorium contents determination as well as for alpha, beta, and gamma dose rates evaluation in various geological and ceramic samples. In this study, uranium and thorium contents have been determined in different plant samples, soils in which they have been grown and in herbal infusions made by boiling the studied plants in potable water by using CR-39 and LR-115 solid state nuclear track detectors. Radon and thoron alpha activities per unit volume inside the plants, soils and herbal infusions studied have been evaluated. The radon transfers between soils and plants as well as between plants and herbal infusions have been investigated. The influence of pollution due to different material dusts on radon and thoron alpha activities inside the plants and their corresponding infusions has been studied. (author)

  16. The OECD/NEA programme on radon and thoron dosimetry and monitoring: its contribution to the assessment of public exposure to natural radiation

    International Nuclear Information System (INIS)

    Ilari, O.; Steinhaeusler, F.

    1984-01-01

    Inhalation of radon, thoron and their daughters is recognised to be the most important pathway to exposure of mankind to natural radiation sources. The progressive understanding of the increasing role of this exposure in the overall radiation detriment to the public and the workers produced an increasing concern in several countries about the problems of dosimetry and measurement of these nuclides. This trend was readily appreciated by NEA, which began an active programme in this field in 1976. The effort of NEA focussed on two main areas, namely (a) development of dosimetric models and study of correlation between exposure and dose (Phase I), and (b) review of principles and techniques of metrology and development of guidance on monitoring (Phase II). (author)

  17. Radiological impact of exposure to radon-thoron and their progeny present in the environment of fly ash dumping site in Faridabad (Haryana)

    International Nuclear Information System (INIS)

    Gupta, Nitin; Kant, Krishan; Garg, Maneesha

    2013-01-01

    Radon-Thoron and their Progeny monitoring was carried out in dwellings near fly ash dumping sites in Faridabad (Haryana), as it is very important from health and hygiene point of view of the occupants. For the measurements, the track etch technique was used. The dosimeter employed for the measurement consisted of twin chamber systems with LR-115 Type II SSNTDs placed on the two sides of the central partition inside the cup and a bare film placed outside it. The detectors were exposed in the mixed field of radon-thoron in the environment of dwellings. The detectors were placed in about 100 dwellings and the choice of the dwelling was random. The value of PAEC, radon concentration, annual exposure, annual effective dose in the dwellings near fly ash dumping sites in District Faridabad (Haryana) varied from 1.34 mWL to 14.05 mWL with an average value of (4.95 0.85) mWL, 12.41 Bqm -3 to 129.91 Bqm -3 with an average value of (45.77 7.87) Bqm -3 , 0.55 10 -1 WLM to 5.83 10 -1 WLM with an average value of (2.04 0.28) 10 -1 WLM and 0.21 mSv to 2.23 mSv with an average value of (0.79 0.13) mSv. The value of PAEC, thoron concentration, annual exposure, annual effective dose in the dwellings near fly ash dumping sites in District Faridabad (Haryana) varied from 1.34 mWL to 14.0 SmWL with an average value of (4.95 0.85) mWL, 1.16 Bq/m 3 to 65.08 Bq/m 3 with an average value of (32.77 7.87) Bqm -3 , 0.55 10 -1 WLM to 5.83 10 -1 WLM with an average value of (2.04 0.28) 10 -1 WLM and 0.21 mSv to 2.23 mSv with an average value of (0.79 0.13) mSv. The measurements indicate that the radon concentration was below the safety levels (action levels) as recommended by various regulatory bodies. The maximum value of 129.91 Bqm -3 was found in a cave inside a temple, where there was no ventilation. The different values of radon concentrations are due to different ventilation conditions and house structures. The radon concentration was found to decrease with the increase in distance of the

  18. 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%.

  19. A field method for monitoring thoron-daughter working level

    International Nuclear Information System (INIS)

    Khan, A.H.; Dhandayatham, R.; Raghavayya, M.; Nambiar, P.P.V.J.

    1975-01-01

    The concept of working level, generally used for radon daughters, has been extended to the daughter products of thoron. Accordingly, thorondaughter working level (TWL) has been defined as the alpha energy released from the ultimate decay of 100 pCi/1 each of the short-lived decay products of thoron. In order to facilitate the evaluation of inhalation hazard in thorium handling areas, a simple field method has been suggested to measure the thoron-daughter working level. A comparison of the potential alpha energies from radon-daughters and that from thoron-daughter is included. (K.B.)

  20. Dose estimation by simultaneous measurement of the radon/thoron concentration and the equilibrium factors in air using a passive dosemeter

    International Nuclear Information System (INIS)

    Urban, M.

    1984-03-01

    Responsible for an increased radiation exposure is the inhalation of radon and its short lived daughters. A time integrating passive dosemeter was developed to determine the concentrations of the radon isotopes as well as their equilibrium factors. The α energy spectrum inside a dosemeter is measured by means of a nuclear track detector. The concentrations in air and the equilibrium factors are calculated by using a new mathematical dosemeter model. A small pilot study in houses was done to test the dosemeter. (orig.) [de

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

    International Nuclear Information System (INIS)

    Slater, M.; Gooding, M.

    2006-01-01

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

  2. Preliminary indoor thoron measurements in high radiation background area of southeastern coastal Orissa (India)

    International Nuclear Information System (INIS)

    Ramola, R. C.; Prasad, G.; Gusain, G. S.; Rautela, B. S.; Choubey, V. M.; Vidya Sagar, D.; Tokonami, S.; Sorimachi, A.; Sahoo, S. K.; Janik, M.; Ishikawa, T.

    2010-01-01

    This paper presents the preliminary results of radon and thoron measurements in the houses of Chhatrapur area of southeastern coast of Orissa (India). This area is one of the high radiation background radiation areas in India, which consists of monazite sand as the source of thoron. Both active and passive methods were employed for the measurements. Radon and thoron concentrations were measured in the houses of Chhatrapur area using twin cup radon dosemeters, RAD7 and radon-thoron discriminative detector (Raduet). Thoron progeny concentration was also measured in the houses using deposition rate measurements. Radon and thoron concentrations in the houses of study area were found to vary from 8 to 47 Bq m -3 and the below detection level to 77 Bq m -3 , respectively. While thoron progeny concentration in these houses ranges between 0.17 and 4.24 Bq m -3 , preliminary investigation shows that the thoron concentration is higher than radon concentration in the houses of the study area. The thoron progeny concentration was found to be comparatively higher, which forms a base for further study in the area. The comparison between the results of various techniques is presented in this paper. (authors)

  3. Preliminary indoor thoron measurements in high radiation background area of southeastern coastal Orissa (India)

    Energy Technology Data Exchange (ETDEWEB)

    Ramola, R C; Prasad, G; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul, Tehri Garhwal 249 199 (India); Choubey, V M [Wadia Inst. of Himalayan Geology, Dehradun 248 001 (India); Vidya Sagar, D [Health Physics Unit (EAD, BARC), IRE, OSCOM, Matikhalo, Dt. Ganjam, Orissa 761 045 (India); Tokonami, S; Sorimachi, A; Sahoo, S K; Janik, M; Ishikawa, T [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263 8555 (Japan)

    2010-07-01

    This paper presents the preliminary results of radon and thoron measurements in the houses of Chhatrapur area of southeastern coast of Orissa (India). This area is one of the high radiation background radiation areas in India, which consists of monazite sand as the source of thoron. Both active and passive methods were employed for the measurements. Radon and thoron concentrations were measured in the houses of Chhatrapur area using twin cup radon dosemeters, RAD7 and radon-thoron discriminative detector (Raduet). Thoron progeny concentration was also measured in the houses using deposition rate measurements. Radon and thoron concentrations in the houses of study area were found to vary from 8 to 47 Bq m{sup -3} and the below detection level to 77 Bq m{sup -3}, respectively. While thoron progeny concentration in these houses ranges between 0.17 and 4.24 Bq m{sup -3}, preliminary investigation shows that the thoron concentration is higher than radon concentration in the houses of the study area. The thoron progeny concentration was found to be comparatively higher, which forms a base for further study in the area. The comparison between the results of various techniques is presented in this paper. (authors)

  4. 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

  5. Implications in estimation of indoor thoron levels: season and ventilation effects

    International Nuclear Information System (INIS)

    Chauhan, R.P.; Amit Kumar

    2015-01-01

    The measurement of radon and thoron in dwellings and workplaces are most important for general public health point. Due to short half life of thoron, sometimes its contribution to radiation doses is assumed to be negligible, but their role is important for areas containing higher thorium content in soil and building materials. The thoron levels in dwellings were determined by various SSNTD detector using different cup geometry and dimensions along with bare mode in past at National and International level. These exercises were carried out in dwellings constructed with different building materials, different ventilation rates and seasons. Most of the times the results of radon and thoron levels were found same in spite of having different diffusion length in air due to different half life. This causes increase in uncertainty in measurement of thoron levels in different season and ventilation. Thus the problem of relative variation of thoron levels in different season and ventilation still exist in radiation field. In this work the measurement of indoor thoron levels from some selected dwelling having different ventilation and in different seasons using Pin hole based radon thoron dosimeters are reported. The results show that indoor thoron value is slightly lower in case of dwellings with poor ventilation, which is contrary to the results published in literature. An effort was made to explain the variation of thoron level under different season and ventilation. Some protocol suggestions are also given at the end of this work for future reference to carry out the measurement and mapping of indoor thoron. (author)

  6. Radon permeability of foils measured by SSNTD technique (non-equilibrium approach)

    Energy Technology Data Exchange (ETDEWEB)

    Hakl, J.; Hunyadi, I.; Toth-Szilagyi, M. (Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete)

    1991-01-01

    Alpha sensitive solid state nuclear track detectors find wide application in the measurement of indoor radon and in field surveys. These detectors are sensitive both to radon and thoron. A separate estimation of concentrations of the two radon isotopes is an everyday problem. One possible way to solve this problem is based on the great difference between the radon and thoron decay constants. This means that thoron can be excluded from the sensitive volume of the radon measuring device by placing a proper gas permeable polymeric membrane over its opening window. The most important parameter determining the suitability of a given membrane for this task is its permeability constant. There are two possible ways to estimate this constant. One is to use long exposure times (>30 days) allowing steady state conditions for the radon concentration to form in the irradiation chamber. The other is to use a more complicated mathematical evaluation. An exact mathematical method has been developed to describe the radon concentration levels inside the irradiation chamber as a function of time. In this case the measurement can be done far from steady-state condition and the required exposure times range from some hours to a few days only. (author).

  7. 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 ...

  8. Thoron and associated risks in the handling of thorium compounds

    International Nuclear Information System (INIS)

    Pradel, J.; Billard, F.

    1959-01-01

    1. Thorium compounds continually give off thoron and its daughters and their radioactivity can constitute a danger for operators who may inhale them. 2. By analogy with radon the maximum admissible content in air of thoron and its daughters has been set at 10 -7 μc/cm 3 . However the differences in behaviour between radon and its active deposit on the one hand, and thoron and its daughters on the other, appear great enough to justify more thorough investigation. In fact it seemed probable that, contrary to what takes place with radon, the thoron + thorium A content at a given point may differ appreciable from the thorium B + thorium C + thorium C' + thorium C'' content at the same point, because of the considerable differences in half-life which allow a greater or lesser distribution. 3. To determine the relative concentrations it was necessary to develop a method for estimating thoron in equilibrium with thorium A, the measurement of thorium B and its daughters being carried out in the conventional way by counting the activity collected on a filter. 4. Another object of this study was to estimate the danger presented by thoron in equilibrium with thorium A in the immediate vicinity of thorium sources, in a plant extracting thorium from urano-thorianite. (author) [fr

  9. The measurement of thoron (220Rn) concentration in indoor air continuously using pylon model WLx

    International Nuclear Information System (INIS)

    Hasnel Sofyan

    2011-01-01

    The concentration of thoron ( 220 Rn) in particular location can be higher than radon ( 220 Rn), however, its presence is always neglected. This might be due to the difficulties in calibration and discrimination between radon and thoron. From biokinetic and dosimetric model, it has been known that the dominant contribution of thoron to the effective dose is in the lungs. UNSCEAR estimates the doses contribution of thoron and its progenies is between 5-10% of the annual dose received by the general public and the risk level is 4.4 times greater than radon and progenies. Therefore, it is necessary to study the thoron concentration in indoor air and workplaces. Radon-thoron concentration in indoor air can be determined by direct methods using Pylon Model WLx device and passive methods using Solid State Nuclear Track Detector (SSNTDs). In this research the measurement of thoron was carried out continuously using Pylon Model WLx equipment that is sensitive to radon for 24, 65, 72, 116 and 154 hours in different rooms. The measurement result showed that the mean value of thoron working level (WL) concentration obtained in room-1 was 2.53 ± 0.67 Bq/m 3 with maximum and minimum of thoron concentrations were 3.37 and 2.22 Bq/m 3 respectively. From the measurement in different locations, it was obtained that the largest and smallest average concentrations of thoron progenies were 0.83 ± 0.23 Bq/m 3 and 0.29 ± 0.64 Bq/m 3 , while the maximum and minimum concentration values were 7.80 Bq/m 3 and 0.01 Bq/m 3 respectively. Pylon Model WLx device is not enables to be used for longer and large scale survey area concurrently, so the SSNTDs which is sensitive to the emission of alpha particles and can measure cumulative thoron concentrations is required. (author)

  10. Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

    International Nuclear Information System (INIS)

    Ramola, R. C.; Gusain, G. S.; Rautela, B. S.; Sagar, D. V.; Prasad, G.; Shahoo, S. K.; Ishikawa, T.; Omori, Y.; Janik, M.; Sorimachi, A.; Tokonami, S.

    2012-01-01

    Exposure to radon, 222 Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, 220 Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to 220 Rn and its progeny can equal or several time exceed that of 220 Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

  11. Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

    Energy Technology Data Exchange (ETDEWEB)

    Ramola, R C; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul Campus, Tehri Garhwal 249199 (India); Sagar, D V [Health Physics Unit EAD, BARC, IRE, OSCOM, Matikhalo, Ganjam, Odisha 761 045 (India); Prasad, G; Shahoo, S K; Ishikawa, T; Omori, Y; Janik, M [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Sorimachi, A; Tokonami, S [Inst. of Radiation Emergency Medicine, Hirosaki Univ., Aomori 036-8564 (Japan)

    2012-07-01

    Exposure to radon, {sup 222}Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, {sup 220}Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to {sup 220}Rn and its progeny can equal or several time exceed that of {sup 220}Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

  12. Radon

    International Nuclear Information System (INIS)

    1990-01-01

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

  13. An overview of thoron and its progeny in the indoor environment

    International Nuclear Information System (INIS)

    McLaughlin, J.

    2010-01-01

    An account is given of the behaviour of thoron and its progeny in the indoor environment. Emphasis is placed on the spatial distribution of these radionuclides in room air and on their interactions with indoor aerosols. How these aspects of thoron and progeny behaviour give rise to special problems for measuring them and assessing their radiological impact are described. Descriptions and comparisons are given of a range of thoron and progeny measurement techniques both passive and active. Recent progress in thoron dosimetry is described as well as compared with radon dosimetry. The results of some indoor thoron and progeny surveys carried out in different countries in recent years are given. As an example of this a summary account is presented of a recently concluded survey of thoron and its airborne progeny in over 200 houses in Ireland. (authors)

  14. Field experience of indoor thoron gas measurements in a stable rural community in Yugoslavia

    International Nuclear Information System (INIS)

    Zunic, Z.S.; Fujimoto, K.; McLaughlin, J.P.; Birovljev, A.

    2000-01-01

    Attempts were made in Yugoslavia to identify rural populations receiving an elevated natural radiation exposure that might be a potential cohort for a planned future health study. In Gornja Stubla at Kosovo in southern Yugoslavia many houses are built mainly from local rock of trachyte which has a uranium content of the order of 25g/t, Th of 61 g/t and K-40 of 5.4%. Thoron and radon gas measurements were carried out in 49 locations in 23 houses in this rural community. Taking into account the short half-life of thoron passive alpha track dual radon-thoron detectors were placed within 10-20 cm from the walls, which were considered the potential source of thoron. Thoron concentrations were found to be extremely high in Gornja Stubla with a maximum measured value of 1,156 Bq/m -3 . Using another type of passive radon detector, designed by SSI/NRPB, annual indoor radon concentrations were measured. The highest indoor radon concentration of 9,591 Bq/m -3 was found in the same house, which had the highest thoron concentration. The absorbed dose rate in air, due to external penetrating radiation was also measured and the highest value found in Gornja Stubla was 430 nGy h -1 . Although high thoron concentrations were recorded it should be pointed out that due to its short half life large differences in thoron concentrations are to be expected as a function of the distance of the measuring point to the source. In addition, with the absence of information on thoron progeny concentration it is impossible to make any estimate of doses from the thoron series since the equilibrium factor between thoron and its progeny can vary greatly with time as well as location. However, the thoron measurements that have been performed in Gornja Stubla clearly indicate that the inhabitants there receive an elevated exposure not only from indoor radon and penetrating radiation but also from thoron. (author)

  15. Radon and radium isotopes trace groundwater discharge into the ocean

    International Nuclear Information System (INIS)

    Burnett, W.C.; Dulaiova, H.; Lambert, M.J.

    2002-01-01

    We construct a mass balance for radon to match inputs via groundwater discharge and diffusion from sediments with outputs via decay, atmospheric evasion, and mixing with offshore waters. The net change in inventory per unit time provides an estimate of the net flux after corrections are made for atmospheric loss. Minimum losses by mixing can be evaluated by use of observed negative net fluxes after other corrections are applied. After estimates for mixing are factored in, one can convert the derived total radon fluxes to water fluxes by dividing by the measured or estimated concentration of radon in the groundwater. This produced results comparable to more labour-intensive methods in recent intercomparison experiments

  16. Studies on thoron progeny implantation in different materials

    International Nuclear Information System (INIS)

    Cosma, C.; Flore, A.; Pop, I.

    2003-01-01

    The purpose of this work is to obtain the alpha spectra for thoron daughters implanted at the surface of different materials and to show the possibility of this method to simulate the radon progeny implantation and thus to find some parameters used in the Jacobi model

  17. Committed effective dose from thoron daughters inhalation

    International Nuclear Information System (INIS)

    Campos, M.P.; Pecequilo, B.R.S.

    2000-01-01

    Mankind's interest in natural radiation exposure levels has increased over the past fifty years and it is now recognized that the most significant contributors to human irradiation by natural sources are the short-lived decay products of radon ( 222 Rn) and thoron ( 220 Rn). Despite the thoron short half-life of 55 s, effective dose from inhalation of thoron an its progeny ( 212 Pb and 212 Bi) must be considered, owing to the high thorium background in countries like Brazil, China and India, for example. The indoor committed effective dose was assessed by air sampling at the thorium purification plant and the nuclear materials storage site of the Instituto de Pesquisas Energeticas e Nucleares; Sao Paulo, Brazil. A total of 21 glass fiber filter samples was analyzed by high resolution gamma ray spectrometry in order to obtain the 212 Pb and 212 Bi activities. The equilibrium equivalent concentration (EEC) varied from 0.3 Bq/m 3 to 6.8 Bq/m 3 for the storage site air samples and from 9.9 Bq/m 3 to 249.8 Bq/m 3 for the thorium purification plant air samples. As retention studies indicate a biological half-life of a few hours inhaled thoron progeny in the human lungs, the main fraction of the potential alpha energy (PAEC) deposited is absorbed in the lungs, meaning negligible to the effective dose the contribution of the dose in other times. The committed effective dose due thoron progeny was performed by compartimental analysis following the ICRP 66 lung compartimental model and ICRP 67 lead compartimental model. The values obtained varied from 0.03 mSv/a to 0.67 mSv/a for the storage site air samples and from 0.12 mSv/a to 6.00 mSv/a for the thorium purification plant air samples. (author)

  18. Outdoor radon levels and dose to the members of public residing in and around the new BARC campus, Visakhapatnam, India

    International Nuclear Information System (INIS)

    Vinod Kumar, A.; Sumesh, C.G.; Krishna, N.S.; Sahoo, S.K.; Tripathi, R.M.; Puranik, V.D.

    2010-01-01

    Natural radiation is the largest contributor to the collective radiation dose to the world population. The greatest fraction of the natural radiation exposure to humans results from inhalation of the short-lived decay products of Radon ( 222 Rn) and Thoron ( 220 Rn), which occur in the free atmosphere and in higher concentrations in the room air of buildings. 222 Rn, being the most important radon isotope in terms of radiation exposure contributes about 55% of the annual radiation dose to the general population from natural radiation sources

  19. Third workshop on radon and radon daughters in urban communities associated with uranium mining and processing. Pt. 1

    International Nuclear Information System (INIS)

    1980-01-01

    This third meeting of Atomic Energy Control Board staff, contractors, federal and provincial government representatives, and delegates from outside Canada was held to discuss progress in reducing concentrations of radon and radon daughters in houses. Speakers talked about successful and unsuccessful remedial measures, methods of measuring and monitoring thoron and radon in houses, and indoor radon concentrations in Canada, Britain and Sweden

  20. Radon

    International Nuclear Information System (INIS)

    Holmen, R.W.

    1987-01-01

    The discovery that radon enters into residential and commercial structures and produces adverse health consequences to occupants thereof has raised issues for the real estate profession in connection with transactions involving affected structures. The legal responsibilities of real estate professionals in relation to such structures have not yet been clearly defined. Moreover, consistent and reliable testing methods and results, clear identification of circumstances where testing is necessary, and consensus as to health risks suggested by various radon levels have yet to be achieved. When these legal and technical questions are clarified, real estate buyer and sellers as well as agents and brokers will be greatly benefited

  1. Optimisation of elevated radon concentration measurement by using electro-chemical etching of nuclear track detectors

    International Nuclear Information System (INIS)

    Celikovic, I.; Ujic, P.; Fujimoto, K.; Tommasino, L.; Demajo, A.; Zunic, Z.; Celikovic, I.)

    2007-01-01

    In the paper, two methods for adjusting of passive radon-thoron discriminative dosimeters (UFO detector) for enhanced radon concentration measurement are presented. Achieved upper limit of detection is 5.94 MBq m-3 d [sr

  2. Determination of internal exposure doses of the personnel of uranium-mining company due to radon isotopes decay products

    International Nuclear Information System (INIS)

    Sevostyanov, V.N.

    2004-01-01

    This work carries out a determination of individual doses of internal exposure of the staff of the uranium-mining company in Kazakhstan due to radon decay products. The company extracts uranium by in-situ leaching. After leaching, uranium is sorbed from a solution in facilities where the staff is located. The state of three uranium mines was analyzed. The dose determination was conducted in tune with the proposed method by using integral alpha-tracking detectors to identify the content of 222 Rn and express appliances to identify the content of radio-active aerosols in air of the working area for determination the equilibrium coefficient. The measurements were performed within one year. The work produced the results in average annual values of radon and thoron decay products activity concentration and variation, equilibrium coefficient variation, and so-called expressive-to-integral value conversion factor. The obtained personnel's individual radiation doses due to radon exposure for this period lie within the range of < 1 mSv/year. (author)

  3. Diffusion coefficients for unattached decay products of thoron - dependence on ventilation and relative humidity

    International Nuclear Information System (INIS)

    Kotrappa, P.; Bhanti, D.P.; Raghunath, B.

    1976-01-01

    The results of a study of the diffusivity of unattached decay products of thoron with respect to air changes using a recently developed diffusion sampler are reported. The dependence of diffusivity of radon/thoron decay products on relative humidity has also been investigated by measurement of diffusion coefficients in an atmosphere where relative humidities varied from 5 to 90%. Results are shown tabulated. (U.K.)

  4. Integrating measurements of indoor thoron and its progeny concentrations

    International Nuclear Information System (INIS)

    Zhuo, W.H.; Iida, T.; Hashiguchi, Y.

    2000-01-01

    In recent years, indoor surveys in Europe and Asia revealed that the dose contribution from thoron and its progeny can equal or even exceed that of radon and its progeny. For measuring thoron and its progeny, several methods had been reported. However, convenient, low-cost and time-integrating measuring methods which are suitable for large-scale surveys are still unavailable. To solve this problem, three integrating measuring methods with allyl diglycol carbonate plastic (CR-39) as detectors have recently been. The results indicated that they are suitable for estimating the indoor thoron and its progeny concentrations when the public exposure to thoron and its progeny is taken into account. Cup monitor - Former types of passive integrating 222 Rn and 220 Rn cup monitors had been reported. Recently, in order to improve the sensitivity of thoron detection, the air exchange rate between the inner and outer cup was enhanced, and the radius of the hemisphere was reduced to 37.5 mm. Furthermore, the procedure of detector exchange was made to be more convenient. Equilibrium-equivalent 222 Rn and 220 Rn concentrations monitor (EEC monitor) - The measuring system is composed of a monitor head and a diaphragm pump. The total weight of the system is less than 1.5 kg, which makes it portable. The construction of the monitor head and the measuring principle were also reported by the authors. Thoron progeny deposition rate monitor - The monitor is simply constituted a piece of CR-39 covered with thin sheets of absorbers. The thickness of the absorbers are adjusted to let only the α particles emitted from 212 Pb impinge on the detector. The concentrations of thoron progeny are estimated from the deposition rates, assuming that the deposition velocities of thoron progeny are constant in general dwellings. The improved cup monitor has higher sensitivity than former monitors, with a calibration factor of 1.59x10 -3 tracks·cm -2 (Bq·m -3 ·h) -1 for thoron. The accuracy of the ECC

  5. Age and sex dependent inhalation doses to members of the public from indoor thoron progeny

    Energy Technology Data Exchange (ETDEWEB)

    Bi, L; Tschiersch, J [Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Institute of Radiation Protection, D-85764, Neuherberg (Germany); Li, W B [Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Department of Medical Radiation Physics and Diagnostics, D-85764, Neuherberg (Germany); Li, J L, E-mail: bilei1983@gmail.com [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2010-12-01

    The increased indoor thoron level in Europe, North America and Asia has shown that the exposure to thoron and its decay products cannot be ignored in some environments. The contribution of thoron and its progeny can be a significant component of the total exposure from radon and thoron. In the present paper, radiation dose assessment of members of the public of different age and sex exposed to {sup 220}Rn progeny under different daily life activities is performed through a dosimetric approach. Dose conversion coefficients under typical indoor conditions were estimated to be in the range of 107 nSv (Bq h m{sup -3}){sup -1} for infant to 81.7 nSv (Bq h m{sup -3}){sup -1} for adult. The results of this work emphasized that small children receive a radiation dose of 25% more than adults under the same conditions, and people performing exercise receive a radiation dose 100% more than when sleeping. The results of this work are appropriate to the risk assessment of thoron exposure to members of the public who live in areas with high radon and thoron concentrations.

  6. The Thoron Issue: Monitoring Activities, Measuring Techniques and Dose Conversion Factors (invited paper)

    International Nuclear Information System (INIS)

    Nuccetelli, C.; Bochicchio, F.

    1998-01-01

    The health risk due to the presence of thoron indoors is usually neglected because of its generally low concentration in indoor environments, which is essentially caused by its short half-life. However, in certain not uncommon situations, such as when thorium-rich building materials are used, thoron ( 220 Rn) may represent a significant source of radioactive exposure. In recent years, renewed interest has led to more intensive monitoring of thoron gas and its decay products. A tentatively comprehensive summary of these measurement results and a review of the most innovative measurement techniques for 220 Rn are here presented. Finally, dose-exposure conversion factors currently used for thoron decay products are analysed, highlighting the poorer basis of such factors, when compared to those for radon. (author)

  7. 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

  8. The measurement of thoron concentrations in Australia using the Japanese passive R-T dosimeter

    International Nuclear Information System (INIS)

    Toussaint, L.F.; Tokonami, S.; Doi, M.; Solomon, S.B.; Peggie, J.R.

    1998-01-01

    Previous studies have shown higher gamma radiation levels and higher soil thorium concentrations in the Darling Scarp area to the east of the city of Perth in Western Australia. It was considered desirable to measure the concentrations of the 220 Rn (thoron) in houses built near such areas and compare these measurements with similar measurements at other sites within Australia. A monitor developed for surveying 220 Rn and 222 Rn levels in Japan was considered most suitable for this purpose. The monitor used for the survey was a passive radon-thoron discriminative dosimeter, similar in type to that used to measure thoron concentrations in traditional Japanese houses. Houses for this study were selected from areas in the Darling Scarp. To provide data on what might be considered typical thoron concentrations associated with other soil types within Australia, a small number of houses in areas on the coastal plain of Western Australia and from the coastal areas of Victoria were also monitored. The mean thoron concentration in homes on the Darling Scarp of 14.0 Bq.m -3 was higher than that in the coastal plain in Western Australia (3.0 Bq.m -3 ) but comparable to the measurements in Victoria (11.3 Bq.m -3 ). For the radon measurements in homes, the mean Scarp concentration was typically 49.2 Bq.m -3 while the WA coastal plain and in Victoria mean concentrations were 11.6 Bq.m -3 and 15.4 Bq.m -3 respectively. For outdoors in the Darling Scarp, the thoron mean was 76.3 Bq.m -3 while the radon level was 18.2 Bq.m -3 . These measurements would suggest that the source of the thoron in homes on the Scarp is from the underlying soil rather than from the building materials. (author)

  9. Thoron and associated risks in the handling of thorium compounds; Le thoron et les risques associes dans la manipulation des composes du thorium

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    1. Thorium compounds continually give off thoron and its daughters and their radioactivity can constitute a danger for operators who may inhale them. 2. By analogy with radon the maximum admissible content in air of thoron and its daughters has been set at 10{sup -7} {mu}c/cm{sup 3}. However the differences in behaviour between radon and its active deposit on the one hand, and thoron and its daughters on the other, appear great enough to justify more thorough investigation. In fact it seemed probable that, contrary to what takes place with radon, the thoron + thorium A content at a given point may differ appreciable from the thorium B + thorium C + thorium C' + thorium C'' content at the same point, because of the considerable differences in half-life which allow a greater or lesser distribution. 3. To determine the relative concentrations it was necessary to develop a method for estimating thoron in equilibrium with thorium A, the measurement of thorium B and its daughters being carried out in the conventional way by counting the activity collected on a filter. 4. Another object of this study was to estimate the danger presented by thoron in equilibrium with thorium A in the immediate vicinity of thorium sources, in a plant extracting thorium from urano-thorianite. (author) [French] 1. Le thoron et ses descendants se degagent constamment des composes du thorium et leur radioactivite peut presenter un danger pour les personnes qui sont amenees a les respirer. 2. Par analogie avec le radon, la teneur maximum admissible dans l'air de thoron et de ses descendants a ete fixee a 10{sup -7} {mu}c/cm{sup 3}. Mais, les differences de comportement du radon et de son depot actif d'une part, du thoron et de ses descendants d'autre part, ont paru suffisantes pour justifier une etude plus complete. Il semblait en effet probable, contrairement a ce qui se produit pour le radon, qu'en un meme point, la teneur en thoron + thorium A puisse differer notablement de la teneur en

  10. Thoron and associated risks in the handling of thorium compounds; Le thoron et les risques associes dans la manipulation des composes du thorium

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    1. Thorium compounds continually give off thoron and its daughters and their radioactivity can constitute a danger for operators who may inhale them. 2. By analogy with radon the maximum admissible content in air of thoron and its daughters has been set at 10{sup -7} {mu}c/cm{sup 3}. However the differences in behaviour between radon and its active deposit on the one hand, and thoron and its daughters on the other, appear great enough to justify more thorough investigation. In fact it seemed probable that, contrary to what takes place with radon, the thoron + thorium A content at a given point may differ appreciable from the thorium B + thorium C + thorium C' + thorium C'' content at the same point, because of the considerable differences in half-life which allow a greater or lesser distribution. 3. To determine the relative concentrations it was necessary to develop a method for estimating thoron in equilibrium with thorium A, the measurement of thorium B and its daughters being carried out in the conventional way by counting the activity collected on a filter. 4. Another object of this study was to estimate the danger presented by thoron in equilibrium with thorium A in the immediate vicinity of thorium sources, in a plant extracting thorium from urano-thorianite. (author) [French] 1. Le thoron et ses descendants se degagent constamment des composes du thorium et leur radioactivite peut presenter un danger pour les personnes qui sont amenees a les respirer. 2. Par analogie avec le radon, la teneur maximum admissible dans l'air de thoron et de ses descendants a ete fixee a 10{sup -7} {mu}c/cm{sup 3}. Mais, les differences de comportement du radon et de son depot actif d'une part, du thoron et de ses descendants d'autre part, ont paru suffisantes pour justifier une etude plus complete. Il semblait en effet probable, contrairement a ce qui se produit pour le radon, qu'en un meme point, la teneur en thoron + thorium A puisse

  11. Individual dosimeter for radon and thoron daughters

    International Nuclear Information System (INIS)

    Chapuis, A.M.; Duport, P.; Zettwoog, P.

    1979-01-01

    The dosimeter is designed for the continuous measurement of the concentration of α emitters from the uranium 238 and thorium 232 series. It enables the measurement of, firstly the aerosol concentration of 218 Po (Radium A), 214 Po (Radium C') and 212 Po (Thorium C') and secondly the activity of long-lived α emitters in aerosols coming from ore dusts. One light weight version of this dosimeter is autonomous for 18 hours and is designed to measure individual doses, due to inhalation, for workers employed in uranium mines and ore processing plants. An other version using the same sampling head allows the monitoring of air concentrations in working environments. Living quarters, or free air

  12. Study of the subterranean estuary of Venice lagoon using radium and radon isotopes

    International Nuclear Information System (INIS)

    Gattacceca, J.

    2009-02-01

    This study focuses on hydrological processes in the southern part of Venice lagoon (Italy), and more specifically on the interactions between surface waters and groundwater of superficial coastal aquifers. These aquifers present a hydraulic head and a ground level below sea level. Major elements and stable isotopes were used to characterize mixing processes into the superficial aquifer. Our results, in agreement with hydrodynamic modelling, evidenced the restriction of saline intrusion to a narrow coastal fringe (≤ 1 km). Submarine groundwater discharge fluxes into the lagoon were quantified using radium and radon natural isotopes. Their activities in the lagoon are in excess compared to the sea. Our results and preliminary modelling work evidence that the system requires an input from groundwater enriched in these isotopes to explain measured activities. A mass balance at steady state is used to quantify the flux. Results vary between 8.1*10 5 and 1.5*10 7 m 3 .d -1 . This flux is mainly due to recirculation of lagoon water into the sediments, and is 2 to 10 times higher than surface runoff, and may have significant environmental consequences by releasing contaminants. (author)

  13. A novel methodology for online measurement of thoron using Lucas scintillation cell

    International Nuclear Information System (INIS)

    Eappen, K.P.; Sapra, B.K.; Mayya, Y.S.

    2007-01-01

    The use of Lucas scintillation cell (LSC) technique for thoron estimation requires a modified methodology as opposed to radon estimation. While in the latter, the α counting is performed after a delay period varying between few hours to few days, in the case of thoron estimation the α counting has to be carried out immediately after sampling owing to the short half-life of thoron (55 s). This can be achieved best by having an on-line LSC sampling and counting system. However, half-life of the thoron decay product 212 Pb being 10.6 h, the background accumulates in LSC during online measurements and hence subsequent use of LSC is erroneous unless normal background level is achieved in the cell. This problem can be circumvented by correcting for the average background counts accumulated during the counting period which may be theoretically estimated. In this study, a methodology has been developed to estimate the true counts due to thoron. A linear regression between the counts obtained experimentally and the fractional decay in regular intervals of time is used to obtain the actual thoron concentration. The novelty of this approach is that the background of the cell is automatically estimated as the intercept of the regression graph. The results obtained by this technique compare well with the two filter method and the thoron concentration produced from a standard thoron source. However, the LSC as such cannot be used for environmental samples because the minimum detection level is comparable with that of thoron concentrations prevailing in normal atmosphere

  14. Calibration of alpha-track monitors for measurement of thoron

    International Nuclear Information System (INIS)

    Pearson, M.D.

    1990-03-01

    The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center (TMC) at the DOE Grand Junction Projects Office (GJPO) to provide standardization, calibration, verification of data, quality assurance, and cost-effectiveness for environmental measurements associated with the various DOE remedial action programs. The GJPO Radon Laboratory has conducted a number of studies evaluating the precision and accuracy of alpha-track monitors for the measurement of airborne radon (Rn-222) concentration. These studies have demonstrated the usefulness of using alpha-track monitors to measure radon. Alpha-track devices have also been proposed for estimating concentrations of thoron (Rn-220). 9 refs., 7 figs., 4 tabs

  15. Radon diffusion chamber

    International Nuclear Information System (INIS)

    Pretzsch, G.; Boerner, E.; Lehmann, R.; Sarenio, O.

    1986-01-01

    The invention relates to the detection of radioactive gases emitting alpha particles like radon, thoron and their alpha-decaying daughters by means of a diffusion chamber with a passive detector, preferably with a solid state track detector. In the chamber above and towards the detector there is a single metallized electret with negative polarity. The distance between electret and detector corresponds to the range of the alpha particles of radon daughters in air at the most. The electret collects the positively charged daughters and functions as surface source. The electret increases the sensitivity by the factor 4

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  17. Estimating SGD flux in the Pingtung Plain coastal area by using Radon and Radium isotopes

    Science.gov (United States)

    Li Chang, Yao; Chieh Su, Chih

    2015-04-01

    In the past two decades, submarine groundwater discharge (SGD) has been recognized as an important pathway to transport material into coastal area. Our study area is located at Pingtung Plain which is the second largest plain in Taiwan with three major rivers, including Gaoping, Donggang and Linbian Rivers, flow through the plain. The Gaoping River, which has the largest drainage area, flows throughout the central part of the plain. The Pingtung Plain composed by four aquifers in different depths (0, 50, 100, and 200 m) and each layer extends to coastal area. Groundwater is an important water resource for local agriculture and aquaculture. However, the long-term over-pumping induced subsidence problem makes salinization at some coastal area. Some previous studies pointed out the SGD accounts for 80% or more of the mass of freshwater in Fangshan coast, depends on salinity and stable isotopes research. In this study, the radioactive tracers, Radon (222Rn, T1/2=3.8 d) and short-lived Ra isotopes (223Ra, T1/2=11.4 d & 224Ra, T1/2=3.6 d) are used in tracing SGD off the Pingtung Plain. During 2013 to 2014, the terrestrial water samples were collected from Gaoping, Donggang, Linbian Rivers and springs in different seasons. We also conducted two coastal waters cruises by using R/V Ocean Researcher 3 (OR3-1768 and 1799 cruises in May and September 2014). Continuous 222Rn was measured by RAD7 equipped with RAD-AQUA system and large volume (20 L) seawater samples were collected by CTD/Rosette water sampler with Niskin sterile bottles. Water samples were flow through Mn-fiber (flow rate < 1 LPM) to concentrate the Ra isotopes, and counted via RaDeCC system. In spatial variation, our result shows the excess 224Ra in the downstream of Gaoping River (2.39 dpm 100L-1) is higher than upstream (1.09 dpm 100L-1). It indicates the groundwater input may play an important role at the downstream of Gaoping River. For temporal variation, excess 224Ra in the Gaoping River are higher in wet

  18. Dynamics of radioactive lead isotopes in the global environmental atmosphere

    International Nuclear Information System (INIS)

    Koike, Yuya; Kosako, Toshiso

    2006-01-01

    Fundamental information of radioactive lead isotopes, which used as the atmospheric tracer in the global environmental atmosphere, is reviewed. Emanation and exhalation of Rn and Tn, parent nuclide, is stated. Some reports on measurement and application of short-lived lead isotopes are reported. Transfer of radioactive lead isotopes in the atmosphere, vertical profiles of radon, thoron, and short-lived lead isotopes for different turbulent mixing conditions, deposition to aerosol, basic processes of Rn decay product behavior in air defining 'unattached' and 'aerosol-attached' activities, seasonal variation of atmospheric 210 Pb concentration at Beijing and Chengdu, seasonal variation of atmospheric 212 Pb concentration at several observation sites in Japan Islands, and variation in the atmospheric concentration of 212 Pb along with SO 2 are shown. (S.Y.)

  19. Establishment of a radon test chamber

    International Nuclear Information System (INIS)

    Chen Chingjiang; Liu Chichang; Lin Yuming

    1993-01-01

    A walk-in type radon test chamber of 23 m 3 has been built for testing and calibration of radon measurement instruments. The environmental conditions of the test chamber can be varied within a wide range of values. The design objectives specification, monitoring instruments and testing results of this chamber are discussed. This test chamber is available for domestic radon researchers and its accuracy can be traced to the international standard. A routine intercomparison study will be held annually by using this chamber. Other tests like radon progeny and thoron standard may also be performed in this chamber. (1 fig.)

  20. Simultaneous Measurements of Nanoaerosols and Radioactive Aerosols Containing the Short-lived Radon Isotopes.

    Czech Academy of Sciences Publication Activity Database

    Otáhal, P.P.S.; Burian, I.; Ondráček, Jakub; Ždímal, Vladimír; Holub, R.F.

    2017-01-01

    Roč. 175, č. 5 (2017), s. 53-56 ISSN 0144-8420. [Conference on Protection against Radon at Home and at Work / 13th International Workshop on the Geological Aspects of Radon Risk Mapping /8./. Prague, 12.09.2017-16.09.2017] Institutional support: RVO:67985858 Keywords : equilibrium-equivalent concentration * radon * radioactive nenoaerosols Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 0.917, year: 2016

  1. 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

  2. Efficient measurement of radon daughters

    International Nuclear Information System (INIS)

    Rolle, R.

    1992-01-01

    In environmental control there is an increasing need for efficient measurement of radon and thoron daughters in air. Measuring instruments should be rugged and portable for field use, while also permitting unattended operation for several days. Simple operating procedures should permit evaluation of rapidly changing concentrations over extended periods. These requirements demand careful balance in the design of hardware and measuring procedures. The design principles for a continuous flow-through spectrometer, that has been developed for precision sequential measurement of radon and thoron daughters, are described. Because of the high precision of measurement, this type of instrument should find application in environments from technologically enhanced natural radiation to the very lowest natural background situations. (author)

  3. 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)

  4. Thoron-in-breath monitoring at CRNL

    International Nuclear Information System (INIS)

    Peterman, B.F.

    1985-04-01

    This report contains a description of the thoron-in-breath monitor (TIBM) developed at CRNL. This monitor can be used to estimate the amount of thorium (Th-232 and/or Th-228) in humans. Thoron-in-breath monitoring is based on the fact that thoron (Rn-220) is a decay product of thorium, and hence deposited thorium produces thoron in vivo, a fraction of which will be exhaled. Experiences with the TIBM indicate that the monitoring is easy to perform and the results in terms of contaminated vs uncontaminated subjects can be easily interpreted. Work on relationships between thoron exhaled and deposited thorium and hence between thoron exhaled and dose, is continuing

  5. An Alpha spectrometer for measuring radon daughter individual activity concentration

    International Nuclear Information System (INIS)

    Berico, M.; Formignani, M.; Mariotti, F.

    2001-01-01

    In the frame of the program of the Institute for Radiation Protection of ENEA, related to the evaluation of dose from radon and thoron progeny, an alpha spectrometer for the continuous air monitoring (CAM type) of radon and thoron has been realized. The constructive characteristics of the device are here presented together with energy and efficiency calibration. The device allows, by means of a screen type diffusion battery and a filter, to determinate the single radioactivity of each radionuclide of the progeny selecting them in relation to their diffusive behaviour (dichotomous particle size selection). The three-count filter method has been employed to measure the concentrations of 218 Po, 214 Pb and 214 Bi in air. Radon and thoron effective doses using a dosimetric, instead of an epidemiologic approach, will be then evaluated [it

  6. Using Radon and Radium isotopes to trace submarine groundwater discharge in Yilan Plain, Taiwan

    Science.gov (United States)

    Huang, Chun-Kai; Su, Chih-Chieh

    2015-04-01

    The Yilan Plain which located in the northeast Taiwan was selected for submarine groundwater discharge (SGD) study. The geomorphic and climatic conditions induce lush rain drenched mountains and create abundant groundwater resource in the Yilan Plain. The annual precipitation in 2014 is 2025 mm with most of the precipitation concentrated on autumn (from September to November). In this study, radon and radium isotopes are used as tracers for SGD survey. The 224Ra (t1/2 =3.6 days) was measured by a delayed coincidence counter (RaDeCC). The 222Rn (t1/2 =3.8 days) was measured by RAD-7 equipped with RAD H2O and RAD AQUA system. The river-water samples were collected from the main stream of Lanyang River and its tributaries from upstream to river mouth. The spring-water samples were collected at 8 sites in April, July and October 2014. Ten surface seawater samples along the coastline of the Yilan Plain were collected in August 2014. Our results show the activities of 222Rn and 224Ra in springs ranging from 3400 to 30850 Bq/m3 and 0.02 to 0.29 Bq/m3, and there are no significant differences between wet and dry seasons. Unexpectedly, the springs are characterized with high 222Rn and low 224Ra activities. For river samples, the activities of 224Ra in downstream and river mouth (0.18 to 1.48 Bq/m3) are higher than upstream (0 to 0.3 Bq/m3). The average activity of 224Ra in downstream samples which collected in April (0.98 Bq/m3) has the highest value than other seasons (0.41-0.51 Bq/m3). In coastal seawater, the activities of 222Rn and 224Ra ranged from 0 to 366 Bq/m3 and 0.10 to 1.14 Bq/m3 in August 2014. In summary, this study points out in some coastal regions of the Yilan Plain, where without riverine input, have high 222Rn and 224Ra activities in seawater. We suggest the SGD plays an important role on land-sea exchange along the coastline of the Yilan Plain. Compare with the spring water samples, the 224Ra activities in coastal seawater are 3-4 times higher than

  7. Measurements of parameters for determining the radon load in the framework of the Dutch national research program SAWORA

    International Nuclear Information System (INIS)

    Groen, G.C.H.; Groot, T.J.H. de; Nyqvist, R.G.; Keverling Buisman, A.S.; Stoute, J.R.D.

    1986-06-01

    This report describes a series of measurements related to the indoor exposure to daughters of radon and thoron. Important parameters are the Potential Alpha Energy Concentration (PAEC) and the Activity Median Aerodynamic Diameter (AMAD). The results for indoor atmosphere are presented leading to an order of magnitude estimate of the effective dose-equivalent rate of 500 μSv/y. The thoron daughter concentrations are relatively high with respect to those of radon daughters. (Auth.)

  8. Nuclear structure studies in the xenon and radon region and the discovery of a new radon isotope by Penning-trap mass spectrometry

    CERN Document Server

    Neidherr, Dennis

    2010-01-01

    Nowadays high-precision mass measurements based on Penning traps allow a deep insight into the fundamental properties of nucleonic matter. To this end, the cyclotron frequency of an ion confined in a strong, homogeneous magnetic field B is determined. At the ISOLTRAP mass spectrometer at ISOLDE / CERN the masses of short-lived radioactive nuclei with half-lives down to several ten ms can be measured with an uncertainty in the order of 10$^{-8}$and below. ISOLTRAP consists of an RFQ cooler and buncher to cool and accumulate the ions coming from ISOLDE and a double Penning-trap system to first clean the ion samples and finally perform the mass measurements. Within this thesis the masses of neutron rich xenon and radon isotopes, namely $^{138-146}$Xe and $^{223-229}$Rn were determined, eleven of them for the first time. $^{229}$Rn was even discovered in this experiment and its half-life could be determined to roughly 12$^{+1.2}_{-1.3}$ s. Since the mass reflects all interactions inside the nucleus it is a unique...

  9. Final survey reports on radon concentration in Japan

    International Nuclear Information System (INIS)

    1997-03-01

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

  10. Reliability of up-to-date risk factor between residential radon and lung cancer

    International Nuclear Information System (INIS)

    Tokonami, Shinji; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Kobayashi, Yosuke; Yoshinaga, Shinji; Quanfu, Sun; Akiba, Suminori

    2008-01-01

    Full text: The WHO launched an international radon project in January, 2005 because two major scientific articles on the residential-radon-and-lung-cancer risk have been published. Furthermore, the ICRP has just issued a new recommendation (Publ. 103). In the publication, radon issues have been mentioned using these references. They show that there is a significant correlation between radon exposures and lung cancer risks even with a somewhat lower radon concentration than an internationally recommended level (200 Bq m -3 ). In most cases, residential radon concentrations were measured by passive integrating radon monitors based on the alpha track detection techniques in their studies. We examined detection responses for the presence of thoron with some typical alpha track detectors (Kf K: Germany, Radtrak: USA and NRPB: UK), which were widely used in many epidemiological studies. In addition, we measured indoor radon and thoron concentrations in cave dwellings in Gansu Province, China, in which the National Cancer Institute (NCI) conducted a large-scale epidemiological study. The NCI concluded that there was also a significant correlation between the two aforementioned parameters, which was a similar value to recently acceptable one. However, our results on radon concentrations were obviously different from them because there was much thoron in that area. The present study demonstrates whether these risk factors are really correct throughout our data or not. Tokonami (2005) has pointed out that some of popular alpha track detectors are sensitive to thoron ( 220 Rn). This finding implies that radon readings will be overestimated and consequently may lead to biased estimates of lung cancer risk. The present study describes thoron interference on accurate radon measurements from the viewpoint of both experimental studies and field experiences. (author)

  11. Influence of environmental changes on continuous radon monitors. Results of a Spanish intercomparison exercise

    International Nuclear Information System (INIS)

    Vargas, A.; Ortega, X.

    2006-01-01

    The first Spanish intercomparison exercise for continuous radon monitors was carried out with the participation of nine monitoring systems from eight laboratories. The exposures were carried out in the radon and thoron chambers at the Inst. of Energy Techniques (INTE) of the Technical Univ. of Catalonia (UPC), which is considered to be the Spanish reference chamber. The monitors were exposed to three different temperatures (13, 20 and 30 deg. C), relative humidities (30, 45 and 80%) and radon concentrations (450, 2000 and 9000 Bq m -3 ). Exposures in the thoron chamber were carried out at concentrations of ∼450 Bq m -3 . The response of the ionisation chambers and scintillation monitors was acceptable. However, the response of monitors based on electrostatic collection was found to be influenced by external climatic conditions. Moreover, all radon monitors were sensitive to thoron concentration, which was especially significant for scintillation monitors. (authors)

  12. Radon concentration distribution mapping in a small detached house

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  13. Environmental thoron (220Rn): a review

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2013-01-01

    Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment and considerable data is generated on the levels of 222 Rn in the environment across the worlds and is periodically reported by UNSCEAR. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. Many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. It is estimated inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54 % of the total natural background radiation dose received by the general population. This component is not adequately estimated for any country so far on a national level. 220 Rn problem will also be a problem in industries which uses thorium nitrate. Including India lamps using thoriated gas mantles are being still used for indoor and outdoor lighting and hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220 Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this article current status of 220 Rn levels in the indoor environment workplaces as well as in other industries where large amount of 232 Th is being handled are being summarized. (author)

  14. Orphan radon daughters at Denver Radium site

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  15. Nuclear structure studies in the xenon and radon region and the discovery of a new radon isotope by Penning trap mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Neidherr, Dennis

    2010-04-28

    Nowadays high-precision mass measurements based on Penning traps allow a deep insight into the fundamental properties of nucleonic matter. To this end, the cyclotron frequency {nu}{sub c}=qB=(2{pi}m) of an ion confined in a strong, homogeneous magnetic field B is determined. At the ISOLTRAP mass spectrometer at ISOLDE / CERN the masses of short-lived radioactive nuclei with half-lives down to several ten ms can be measured with an uncertainty in the order of 10{sup -8} and below. ISOLTRAP consists of an RFQ cooler and buncher to cool and accumulate the ions coming from ISOLDE and a double Penning trap system to first clean the ion samples and finally perform the mass measurements. Within this thesis the masses of neutron rich xenon and radon isotopes, namely {sup 138-146}Xe and {sup 223-229}Rn were determined, eleven of them for the first time. {sup 229}Rn was even discovered in this experiment and its half-life could be determined to 12{sub -1.3}{sup +1.2} s. Since the mass reflects all interactions inside the nucleus it is a unique fingerprint of the nuclide of interest. One of these interactions, the proton-neutron interaction, leads for example to the onset of deformation. The aim of this thesis is to investigate a possible connection be- tween collective effects in nuclei, like the onset of deformation, and double-differences of binding energies, so called {delta}V{sub pn} values. Especially in the here presented areas these {delta}V{sub pn} values show a very unusual behavior and can not be explained with simple orbital overlapping arguments. One explanation could be the occurrence of octupolar deformation in these regions, which is usually probed with other experimental techniques. However, a quantitative description of the influence of such type of deformation on {delta}V{sub pn} is still not possible with modern theories. (orig.)

  16. Nuclear structure studies in the xenon and radon region and the discovery of a new radon isotope by Penning trap mass spectrometry

    International Nuclear Information System (INIS)

    Neidherr, Dennis

    2010-01-01

    Nowadays high-precision mass measurements based on Penning traps allow a deep insight into the fundamental properties of nucleonic matter. To this end, the cyclotron frequency ν c =qB=(2πm) of an ion confined in a strong, homogeneous magnetic field B is determined. At the ISOLTRAP mass spectrometer at ISOLDE / CERN the masses of short-lived radioactive nuclei with half-lives down to several ten ms can be measured with an uncertainty in the order of 10 -8 and below. ISOLTRAP consists of an RFQ cooler and buncher to cool and accumulate the ions coming from ISOLDE and a double Penning trap system to first clean the ion samples and finally perform the mass measurements. Within this thesis the masses of neutron rich xenon and radon isotopes, namely 138-146 Xe and 223-229 Rn were determined, eleven of them for the first time. 229 Rn was even discovered in this experiment and its half-life could be determined to 12 -1.3 +1.2 s. Since the mass reflects all interactions inside the nucleus it is a unique fingerprint of the nuclide of interest. One of these interactions, the proton-neutron interaction, leads for example to the onset of deformation. The aim of this thesis is to investigate a possible connection be- tween collective effects in nuclei, like the onset of deformation, and double-differences of binding energies, so called δV pn values. Especially in the here presented areas these δV pn values show a very unusual behavior and can not be explained with simple orbital overlapping arguments. One explanation could be the occurrence of octupolar deformation in these regions, which is usually probed with other experimental techniques. However, a quantitative description of the influence of such type of deformation on δV pn is still not possible with modern theories. (orig.)

  17. Radon: Not so Noble

    Indian Academy of Sciences (India)

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

  18. Radon measurements over a natural-gas contaminated aquifer

    International Nuclear Information System (INIS)

    Palacios, D.; Fusella, E.; Avila, Y.; Salas, J.; Teixeira, D.; Fernández, G.; Salas, A.; Sajo-Bohus, L.; Greaves, E.; Barros, H.; Bolívar, M.; Regalado, J.

    2013-01-01

    Radon and thoron concentrations in soil pores in a gas production region of the Anzoategui State, Venezuela, were determined by active and passive methods. In this region, water wells are contaminated by natural gas and gas leaks exist in the nearby river. Based on soil gas Radon data surface hydrocarbon seeps were identified. Radon and thoron concentration maps show anomalously high values near the river gas leaks decreasing in the direction of water wells where natural gas is also detected. The area where the highest concentrations of 222 Rn were detected seems to indicate the surface projection of the aquifer contaminated with natural gas. The Radon/Thoron ratio revealed a micro-localized anomaly, indicating the area where the gas comes from deep layers of the subsoil. The radon map determined by the passive method showed a marked positive anomaly around abandoned gas wells. The high anomalous Radon concentration localized near the trails of ascending gas bubbles at the river indicates the zone trough where natural gases are ascending with greater ease, associated with a deep geological fault, being this the main source of methane penetration into the aquifer. It is suggested that the source of the natural gas may be due to leaks at deep sites along the structure of some of the abandoned wells located at the North-East of the studied area. - Highlights: ► High Radon/Thoron ratios were localized near the natural-gas emanations in a river. ► Natural gases are ascending trough a deep geological fault. ► Apparently, the radon anomaly shows the site where natural gas enters the aquifer. ► Natural gas source may be related to leaks in the structure of abandoned gas wells

  19. Seasonal variation of radon concentration in different rooms of dwellings

    International Nuclear Information System (INIS)

    Jayasheelan, A.; Manjunatha, S.; Chandrashekaraiah, G.; Shankar, P.; Umeshareddy, K.; Ningappa, C.

    2016-01-01

    Indoor air is a dominant exposure for humans, where more than half of the body's intake during a lifetime. The main natural sources of indoor radon are soil, building materials like sand, rocks, cement, marble, bricks, ceramics, natural gas and the underground-derived water supply. In the present research, dwellings with similar building style (similar floorings and dimensions) from Tumkur city were studied for indoor radon, thoron and their progeny measurements for various seasons

  20. A charcoal canister survey of radon emanation at the rehabilitated uranium mine site at Nabarlek

    International Nuclear Information System (INIS)

    Storm, J.R.; Patterson, J.R.

    1999-01-01

    This paper describes a recent survey of radon emanation measurements from the rehabilitated Nabarlek mine site. It was mined out in 1979, decommissioned in 1995 and provided a good test bed for assessment of rehabilitation in terms of radon flux attenuation. Measurements have been made with charcoal canisters. Studies to measure the radon-220 flux by observing Tl-208 progeny of thoron the effectiveness of trial covers and meteorological considerations will be reported

  1. A charcoal canister survey of radon emanation at the rehabilitated uranium mine site at Nabarlek

    Energy Technology Data Exchange (ETDEWEB)

    Storm, J R; Patterson, J R [University of Adelaide, Adelaide, SA (Australia). Department of Physics and Mathematical Physics

    1999-07-01

    This paper describes a recent survey of radon emanation measurements from the rehabilitated Nabarlek mine site. It was mined out in 1979, decommissioned in 1995 and provided a good test bed for assessment of rehabilitation in terms of radon flux attenuation. Measurements have been made with charcoal canisters. Studies to measure the radon-220 flux by observing Tl-208 progeny of thoron the effectiveness of trial covers and meteorological considerations will be reported.

  2. Radiation protection against radon in workplaces other than mines

    International Nuclear Information System (INIS)

    2003-01-01

    The radioactive gases radon and thoron and their decay products are ubiquitous in the open atmosphere.They are found in higher concentrations in the confined atmospheres of buildings and underground workplaces where workers are exposed to these radionuclides. Exposures to radon and thoron and their decay products may be extremely variable.The main radon source in most above ground workplaces with high radon concentrations is the soil, but there can also be significant contributions from building materials, groundwater, and the storage and processing of large amounts of materials with elevated concentrations of radium. Underground workplaces can accumulate high radon levels, as can natural caves and abandoned mines. In some instances, members of the public may be exposed to radon and thoron and their decay products at workplaces. The establishment of safety requirements and the provision of guidance on occupational radiation protection form a major part of the IAEA's support for radiation safety in Member States. The objective of the IAEA's occupational radiation protection programme is to promote an internationally harmonized approach to the optimization of occupational radiation protection through the development and application of guidelines for restricting radiation exposures and applying current radiation protection techniques in the workplace. Guidance on conducting dose assessments and recommendations concerning dose limitation are given in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, issued as IAEA Safety Series No. 115 in 1996. Recommendations on the fulfilment of requirements are also given in three interrelated Safety Guides, Occupational Radiation Protection (IAEA Safety Standards Series No. RS-G-1.1), Assessment of Occupational Exposure due to Intakes of Radionuclides (No. RS-G-1.2), and Assessment of Occupational Exposure due to External Sources of Radiation (No. RS-G-1

  3. Application of CR-39 to radon measurement

    International Nuclear Information System (INIS)

    Miyake, Hiroshi

    1988-01-01

    CR-39, an ally diglycol carbonate, has recently come into wider use as material for solid-state track detector. Etching with NaOH or KOH solution allow CR-39 to develop extremely clear etch pits attributed to alpha rays. The most widely used method for measuring radon concentration employs a plastic cup with a solid-state track detector mounted at its bottom to detect alpha rays resulting from radon or its daughters that disintegrate within or on the wall of the cup. Simple in mechanism and low in cost, this method is suitable for such a case where the radon concentration distribution over a wide area has to be measured by using a large number of devices. The concentration of radon alone can be measured with the aid of a filter attached to the mouth of the cup to remove the daughters of radon and thoron. The simplest and most effective way of improving the sensitivity of a solid-state track detector for radon concentration measurement is to electrostatically collect daughters resulting from decay of radon onto the surface of the detector. Another method widely used to determine the radon concentration is to measure the concentration of the radon daughters instead of direct measurement of the concentration of radon itself. (Nogami, K.)

  4. Risk assessment of exposure to radon concentration in indoor atmosphere and drinking water of Shimoga city, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamy, D.R.; Sannappa, J.; Srinivasa, E.

    2016-01-01

    The exposure of population to natural sources of radiation has become an important issue in terms of radiological protection. The major contribution of dose from natural radiation in normal background regions arises due to inhalation of alpha-emitting radon and thoron, and their progenies, which are ubiquitous in both indoor and outdoor environs. The aim of the present study is to measure indoor radon, thoron and their progeny levels in the dwellings of Shimoga city and radon concentration in drinking water and to estimate the annual effective dose. The indoor concentration of radon, thoron and their progeny was measured using Solid-State Nuclear Track Detectors (SSNTDs) based twin chamber dosimeter cups. The 222 Rn concentration in drinking water was estimated by the Emanometry technique

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

    Directory of Open Access Journals (Sweden)

    Amanat B

    2013-12-01

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

  6. The German thoron progeny chamber-Concept and application

    International Nuclear Information System (INIS)

    Roettger, Annette; Honig, Anja; Arnold, Dirk

    2009-01-01

    Following completion of the project 'Generation and characterisation of reference atmospheres of thoron decay products for the calibration of measuring devices for thoron decay products', the Physikalisch-Technische Bundesanstalt (PTB) now operates a thoron progeny chamber in which 220 Rn (thoron), 222 Rn and its progenies can be made available under almost all ambient conditions. This allows all measuring systems to be calibrated under realistic climatic conditions with an accuracy unique worldwide.

  7. Diffusive Soil Degassing of Radon and Carbon Dioxide at Ilopango Caldera, El Salvador, Central America

    Science.gov (United States)

    Ransom, L.; Lopez, D. L.; Hernandez, P.

    2001-12-01

    Ilopango Caldera lies 10 Km east of San Salvador, El Salvador and holds Ilopango Lake, the largest body of fresh water in El Salvador. There is currently no observed fumarolic activity within the caldera system. However, the last eruption occurred in 1880. In November - December, 1999, radon gas concentrations (pCi/l) were measured using a Pylon AB5 radon monitor, and flux of CO2 (g/m2/day) was determined using the accumulation chamber method at 106 sampling stations around the lake, along and across the caldera walls. Gas samples were also collected to determine the isotopic composition of C in CO2. CO2 fluxes did not show high values characteristic of other volcanic systems, values ranged from 0.7 to 9.2 g/m2/day with an average value of 3.9. These values are similar to the low values of the background population observed in nearby San Salvador volcano. Highest values are observed to the east and west of the lake. Isotopic values for C in soil gases do not show an important magmatic component. Radon concentrations present three distinct populations with the highest values occurring to the southwest. Thoron concentrations are higher close to the caldera walls than inside the caldera due to the possible higher rock fracturing in that region. Measurements taken in March 2001, after the January 13 and February 13, 2001 earthquakes did not show significant variations in CO2 fluxes. However, radon concentrations varied due to the high seismicity that lasted several months after these earthquakes. These results suggest that the magmatic system of Ilopango Caldera is not emitting high fluxes of CO2 to the atmosphere throughout the caldera soils. Subaquatic emissions of CO2 have not been evaluated. However, subaquatic hydrothermal discharges have not been identified at this calderic lake.

  8. Protective measures during construction against radon exposure

    International Nuclear Information System (INIS)

    Horn, W.

    1990-01-01

    Radon, thoron as well as their daughter products have an cancerogeneous effect on the human respiratory tracts. In this respect protective measures in the area of construction are of great importance. This article deals with constructional solutions which consist of different individual measures. Sources of radon are outside air, water, fuels, building materials as well as the building ground. Possible protective measures are divided into area-related (floor structure, intermediate floors, exterior walls of cellar, foundation slab, building ground), line-related (joints, cracks, wall ducts) as well as supplementary measures (tightly closing doors, arrangement of natural cross-ventilation and vertical ventilating shafts). (BWI) [de

  9. Thoron (220Rn) in the indoor atmospheric environment

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2006-01-01

    Naturally occurring background radiation is a topic, which has evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Many locations around the world have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It has been estimated that inhalation of 222 Rn, 2 20 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. In the Indian context, in an earlier national survey, the external gamma radiation dose rates have been more or less well mapped using thermo luminescent dosimeters covering more than 214 locations, which has yielded a national average of 775 mGy/y. Of this, nearly 48.7% contribution of the dose rate is from 40 K and the rest from the uranium (33.6%) and thorium (17.7%) series. A good database pertaining to the country wide levels of uranium, thorium and potassium in geological materials also exists. Thus, there exists a good database on the total external gamma radiation level across the country. Since the contribution from inhalation of 222 Rn, 220 Rn and their short lived progenies contributes more than 54% of the total background radiation dose, it was necessary to supplement the external component with inhalation component. This component is not adequately estimated for the country so far on national level. With this in mind, a national survey has been executed by this center involving a large number of universities and other allied research institutions from different parts of the country for the estimation of inhalation component of the dose

  10. 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

  11. Radon and thoron anomalies along Mat fault in Mizoram, India

    Indian Academy of Sciences (India)

    Figure 1. (a) Location map of the study area and (b) spatial distribution of earthquakes ... Ground surface. Lid ... LR-115 film facing up ... cylinders with the bottom open and top with a lid ..... and Tiwari R P 2010 Magnetic polarity stratigraphy of.

  12. Radon and thoron in cave dwellings (Yan'an, China)

    International Nuclear Information System (INIS)

    Wiegand, J.; Feige, S.; Xie Quingling; Schreiber, U.; Wieditz, K.; Wittmann, C.; Luo Xiarong

    2000-01-01

    222 Rn and 220 Rn concentrations were measured in cave dwellings and brick houses in the region of Yan'an (China) during summer 1997. The underground dwellings are built into Quaternary loess, and all investigated houses are founded on it. The median values of indoor 222 Rn and 220 Rn concentrations are 42 (n = 18) and 77Bq m -3 (n = 15) for brick houses and 92 (n = 23) and 215 (n = 17) Bq m -3 for cave dwellings. To classify the dwellings in respect to their cave-character, the fraction of walls having a direct contact to the loess is calculated for each dwelling. While the 222 Rn concentrations are increasing with higher fractions, the 220 Rn concentrations are not correlated with this fraction. On the other hand, due to the short half-life of 220 Rn the distance from the measuring point to the walls is negatively correlated with the 220 Rn concentration, while there is no correlation with the 222 Rn concentration. Therefore, concentric isolines of 220 Rn concentrations showing a strong gradient were detected in cave dwellings. An influence of the ventilation rate is distinct for 222 Rn but weak for 220 Rn. The effective dose rates for 222 Rn and 220 Rn and their progenies are calculated for brick houses (2.7 mSv y -1 ), cave dwellings (7.1 mSv y -1 ), and for traditional cave dwellings with a bed foundation built with loess (16.7 mSv y -1 ). These calculations are based on summer measurements only. It is expected that the true effective dose rates will be significantly higher

  13. Determination of thoron and radon ratio by liquid scintillation spectrometry

    International Nuclear Information System (INIS)

    Yoshikawa, H.; Nakanishi, T.; Nakahara, H.

    2006-01-01

    A portable liquid scintillation counter was applied for the analysis of alpha-ray energy spectrum to determine the ratio of 220 Rn/ 222 Rn in fumarolic gas in the field. A surface-polished vial was developed, by which a Gaussian distribution could be approximated for the alpha-ray energy spectra and the peak areas of the nuclides could be estimated independently, because of the wide FWHM in the liquid scintillation pulse. A fumarolic gas sample was collected in Mt. Kamiyama (Hakoneyama geothermal field in Japan) having low 220 Rn/ 222 Rn ratio of 2.20 ± 0.13. (author)

  14. Determine concentration radon 222Rn in the air inside and outside the buildings at the summer province of Baghdad

    International Nuclear Information System (INIS)

    Al-Ataby, N.R.; Aisa, B.H.; Jebir, H.M.; Hatem, J.N.

    2010-01-01

    In this study, Was use of solid-state nuclear track detectors in the measurement of concentrations of radon 222 Rn inside and outside of the buildings in the summer and winter of the Baghdad province and because of the high features of the technical sensitivity and efficiency to record track of charged particles (such as protons and alpha particles and fission fragments) . Is the radon of Environmental Pollutions that is caused health problems , that was seemed the concern at the problem of pollution, radon gas 222 Rn and thoron gas 220 Rn and the considerable risk resulting from exposure to these isotopes by alpha particles emitted which have proved the relationship between exposure to emitted alpha particles with the incidence of disease of lung cancer. In this study, measured the concentration of radon 222 Rn inside and outside buildings in the summer and winter in several areas from the Baghdad province and as showed in the attached tables. Been studied the environmental radioactivity and measurement of the concentration of radon gas in the air in different parts of the city of Baghdad. the highest concentration was Found in the second Orf ali (A) (of the Sadr City) for the summer and was (37.973 Bq/m3) outside the building and ((53.400 Bq/m3 inside the building, either for the winter season was (55.773 Bq/m3) outside the building and (Bq/m3 58.148) inside the building for the same region and This is the concentration within the limits allowed

  15. Radiological characterisation and radon equilibrium factor in the outdoor air of a post-industrial urban area

    International Nuclear Information System (INIS)

    Rozas, S.; Idoeta, R.; Alegría, N.; Herranz, M.

    2016-01-01

    The radiological characterisation of outdoor air is always a complicated task due to the several radioactive emissions coming from the different radionuclides and also because of the very short half-lives of radionuclides in the natural radioactive series. In some places, this characterisation could result in unusual values because the natural presence of radionuclides with terrestrial origin can be modified by manmade activities. Nonetheless, this characterisation is useful not only for air quality control purposes but also because radon and its progeny in the outdoor air are the main contributors to human exposure from natural sources. In this study, we have carried out air particle sampling, followed by gamma-ray spectrometry, alpha spectrometry and beta counting determinations for this purpose. Subsequently, the outdoor air has been radiologically characterised through the obtained data and using a pre-existing analytical method to take into account the radioactive decays of short half-life radionuclides during sampling, sample preparation and measuring times. Bilbao was chosen to carry out this work. It is a medium-sized town located in northern Spain, close to the Atlantic Ocean and at sea level. This city has a recent industrial past as there were numerous steel mills and other heavy industries, including some quarries, and some open pit mines close to it, which concluded in a remediation program. So, it is a place where the air is potentially modified by manmade activities. The obtained results show that activity concentration values for long-lived radionuclides that precede radon and thoron are in the order of 10 −6  Bq m −3 and long-lived ones after radon are around 10 −4  Bq m −3 . Thoron progeny are around 2 × 10 −2  Bq m −3 and radon progeny are around 1.8 Bq m −3 . The mean radon equilibrium factor was 0.18. All of these values are close to the minimum UNSCEAR values, but show some variability, which highlights the importance

  16. Radon in a Karstic Region School: Concentrations in Soil Gas and Indoors

    International Nuclear Information System (INIS)

    Vaupotic, J.; Kobal, I.; Barisic, D.; Lulic, S.

    1998-01-01

    The school presented in this paper exceeded instantaneous indoor radon concentration of 1000 Bqm -3 , obtained within the Slovene radon programme. Thus, additional measurements were performed and the radiation doses of teachers and pupils estimated. Radon concentrations between 1000 and 3000 Bqm -3 during teaching hours were found and the yearly effective doses from 0.75 to 1.1 mSv for the pupils and from 1.1 to 4.2 mSv for the teachers were calculated. In the soil gas radon and thoron concentration ranging from 70 to 150 kBqm -3 were obtained. The school was mitigated during summer 1998. (author)

  17. Comparative study of radon exposure in Canadian homes and uranium mines - a discussion on the importance of national radon program

    International Nuclear Information System (INIS)

    Chen, Jing

    2017-01-01

    The history of lung cancer in uranium miners is well known for over hundreds of years when the disease was referred to as 'miner's disease' or 'mountain sickness'. Radon levels in uranium mines have decreased significantly over the past 30 years as a result of effective radiation protection measures at workplaces. For the most recent 10-year period, the average radon concentrations to underground and surface workers in Canadian uranium mines were 111 and 11 Bq m -3 , respectively. Based on the recent radon survey carried out in roughly 14 000 homes in 121 health regions across Canada and the more recent radon and thoron survey in 33 Canadian cities and 4000 homes, the average radon concentration in Canadian homes is 77 Bq m -3 . This study demonstrates that, nowadays, workers are exposed to radon in underground mines at a comparable radon level to what Canadians are exposed to at home. Since exposure to indoor radon is the main source of natural radiation exposure to the population, it is important for the National Radon Program to further increase radon awareness, and to encourage more Canadians to take appropriate actions to reduce radon exposure. (authors)

  18. Environmental thoron (220Rn): a review

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2008-01-01

    Studies on natural background radiation is a topic, which evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment. Subsequently, considerable data is being generated on the levels of 222 Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scare due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true from the recent studies resulted in observing high 220 Rn levels in living environments and work places in various countries and it is increasingly felt that it may be necessary to have data on 220 Rn levels in environment for obtaining a complete picture of inhalation dose. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products, like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54 % of the total natural background radiation dose received by the general population. Due to this it was necessary to supplement the external component with inhalation component. This component is not

  19. Environmental radon

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  20. Metal screen retention for thoron daughter free atoms and atoms attached to condensation nuclei

    International Nuclear Information System (INIS)

    Cash, W.; Webb, J.; Fitts, D.; Skrable, K.W.; Chabot, G.E.

    1978-01-01

    Metal support screens available in a 47 mm commercial filter holder (model F3052-4, available from Scientific Products, Bedford, MA) assembly were tested for retention of thoron daughter atoms and atoms attached to condensation nuclei as a function of the flow rate of the carrier air stream. Sources of Pb-212 were generated on the surface of a metal disk by exposing the disk to thoron emanation generated from a special preparation of Th-228. This source of Pb-212, in transient equilibrium with its daughters, was placed in a flow through chamber connected in series to two of the metal screens backed by a glass fiber filter. Most of the recoil product radioactivity emitted from the Pb-212 source and collected on the screens was due to single atoms of Tl-208, which is born by alpha decay of Bi-212 with a recoil energy of 116 keV. Some free atoms of Bi-212 were also observed. Alpha autoradiographs of Filter samples placed on the downstream side of the two metal screens gave proof of the existence of Pb-212 aggregates through their alpha star images. These aggregate recoil particles were found to have a much higher penetration through the screens than free atoms of Tl-208 and Bi-212. Penetration of Tl-208 atoms and ions decreased exponentially as the inverse of the carrier air flow rate. Penetration varied from 0.047 at 0.088 cfm to 0.661 at 2.47 cfm. Atoms of Pb-212 attached to condensation nuclei were obtained by passing thoron into a reaction chamber containing naturally occurring condensation nuclei from the laboratory. The retention for these attached species varied both as a function of the flow rate and the age of the aerosol. The maximum retention varied from 0.525% at 6.38 cfm to 3.5% at 0.636 cfm for respective delay times of 120 and 30 minutes post the introduction of the thoron into the reaction chamber. A system consisting of a single screen backed by a glass fiber filter may be used to obtain the numbers of radon or thoron daughter free atoms and attached

  1. Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals

    International Nuclear Information System (INIS)

    Ishimori, Y.; Mitsunobu, F.; Yamaoka, K.; Tanaka, H.; Kataoka, T.; Sakoda, A.

    2011-01-01

    A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects. (authors)

  2. A study of environmental radon levels in rammed earth dwellings in the south west of Western Australia

    International Nuclear Information System (INIS)

    Walsh, M.; Jennings, P.

    2002-01-01

    Indoor radon and thoron progeny Equilibrium Equivalent Concentrations (EEC) were measured with a portable 'Radon Sniffer' in 10 rammed earth dwellings and 10 conventional dwellings in Margaret River in the South West of Western Australia. Natural background gamma radiation was also measured within the dwellings. The results of this study show that the mean indoor radon progeny concentrations in rammed earth and non-rammed earth dwellings was 24 Bq m -3 EEC and 9.3 Bq m -3 EEC respectively. The mean indoor thoron progeny concentrations in rammed earth and non-rammed earth dwellings was 3.9 Bq m -3 EEC and 0.8 Bq m -3 EEC respectively. The ranges of combined indoor radon and thoron progeny concentrations in rammed earth and non-rammed earth dwellings were between 2.1 and 76 Bq m -3 EEC and 2.0 and 27 Bq m -3 EEC respectively. The mean annual effective radiation dose equivalents from combined indoor radon and thoron progeny concentrations EEC using UNSCEAR's (1982) conversion factors in rammed earth and non-rammed earth dwellings were 4.1 mSv y -1 and 2.2 mSv y -1 respectively. Copyright (2002) Australasian Radiation Protection Society Inc

  3. Radon -- an environmental hazard

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  4. Radon analyser

    International Nuclear Information System (INIS)

    1981-01-01

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

  5. Radon isotopes at Wairakei

    International Nuclear Information System (INIS)

    Barry, B.J.; Whitehead, N.E.

    1994-01-01

    We report the presence of the short lived radioactive noble gas 2 20Rn (half-life 56 seconds) in geothermal steam at Wairakei. It is detected by a radiochemical separation of Pb, and gamma spectrometry. Measured levels of 2 20Rn and the longer lived 2 22Rn are interpreted as reflecting processes taking place near the feed zones of the sampled wells. (author). 2 figs., 1 tab., 18 refs

  6. Radon in your dwellings - problems and mitigation

    International Nuclear Information System (INIS)

    Srivastava, D.S.

    2011-01-01

    The problem of radon in dwellings gained importance in 1984 after the Stanely Watra's house incidence in Pennsylvania USA. Since then several radon measuring techniques have been identified and instrumentations developed. National survey programs were started for monitoring radon levels in dwellings by Government authorities in all developed and developing countries including India. Successively, the measurement of thoron levels was also found desirable especially in high radiation background areas. A lot of work has been done since then by scientists and university researches and thousands of publications have been made in this field. Several developed countries have given guide lines for initiating action to reduce radon levels in dwellings if it is beyond 200-400 Bq/m 2 . The recommended 'action level' is found to depend upon the authorities making the recommendations. This talk is aimed to produce public awareness about the health hazard posed by concentration of naturally occurring radon gas in our dwellings, the sources of its production and mitigation of radon problem. The matter will be discussed in a general way using ppt presentation. (author)

  7. Comparison of different methods for thoron progeny measurement

    International Nuclear Information System (INIS)

    Bi Lei; Zhu Li; Shang Bing; Cui Hongxing; Zhang Qingzhao

    2009-01-01

    Four popular methods for thoron progeny measurement were discussed, including the aspects of detector,principle, precondition, calculation advantages and disadvantages. Comparison experiments were made in mine and houses with high background in Yunnan Province. Since indoor thoron progeny changes with time obviously and with no rule, α track method is recommended in the area of radiation protection for environmental detection and assessment. (authors)

  8. Radon in Schools

    Science.gov (United States)

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

  9. 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

  10. Review of epidemiological studies on hazards of radon daughters

    International Nuclear Information System (INIS)

    Myers, D.K.; Stewart, C.G.; Johnson, J.R.

    1981-01-01

    A review, with nearly 100 references, of the biological effects of radon and radon daughters is presented. Calculations of the relative dose from daughter products, as well as of the variation in dose with such things as unattached fraction, particle size, age and breathing rate are discussed. Estimates of annual risk of lung cancer in miners after inhalation of thoron daughters are given, and compared with hazards of employment in various US industries. The implications of these epidemiological studies for future regulations are discussed

  11. Estimating back to front ratio of wire screen for measurement of thoron decay products

    International Nuclear Information System (INIS)

    Koli, Amruta; Khandare, Pallavi; Joshi, Manish; Mariam; Khan, Arshad; Sapra, B.K.

    2016-01-01

    Wire screens are widely used for measuring the fine fraction of radon/thoron decay products. Their capture efficiencies are generally defined at low aerosol concentration conditions as well as at low sampling flow rates. Effect of changes in sampling flow rate and aerosol concentration on wire screen capture efficiencies and counting correction factor has been studied in this work. Controlled experiments have been conducted using two different mesh sizes at two different aerosol concentration conditions. Experimental results were compared with the existing theories for capture efficiencies of wire screens given by Cheng and Yeh (1980) and Alonso et al. (2001); and semi empirical relation for the front to total ratio given by Solomon and Ren (1992). Theoretical predictions have been found to be relatively close to the experimental findings for moderate aerosol conditions but disagreement was observed in case of high aerosol concentration. The possible reasons for these differences have been discussed in this work. - Highlights: • Effect of Fiber Reynolds number on capture efficiency and back to front ratio of wire screen. • Experiments with Thoron decay products at moderate and elevated aerosol concentrations. • Comparison with theoretical estimates. • Fair agreement observed for moderate aerosol concentration.

  12. Dosimetry of radon, thorium and their progenies in the environment of a chemistry lab and crude in Zulia State, Venezuela

    International Nuclear Information System (INIS)

    Pineda, L.; Viloria, T.; Palacios, D.; Sajo-Bohus, L.

    2013-01-01

    The main objective of this study was to estimate the dose rate of inhalation and the annual contribution of effective dose in the mixed field of radon and thoron in the environment of laboratory chemicals and oil from Zulia State, Venezuela, due to manipulation and storage of oil samples and water production

  13. 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)

  14. 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)

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

    International Nuclear Information System (INIS)

    Espinosa, G.; Tommasino, L.

    2015-01-01

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

  16. Indoor Radon-222 concentration measurements during the summer season of year 2000 in some houses in the western part of Yatta City

    International Nuclear Information System (INIS)

    Abu-Samreh, Mohammad M.

    2005-01-01

    Radon, as a natural noble gas, has three main natural isotopes; namely, radon 222 (Rn), a decay product of 238U, radon-220(220Rn, known as thoron), produced in the decay series of thorium-232(232Th), and radon-219 (219Rn), a decay product from the chain originating with 235U [1]. Both 238U and 232th occur naturally in soil and rocks at variable concentrations of about 1pCi/g and also 226Ra, the parent of 222Rn [2]. The 222Rn isotope has half-life of 3.82 days; while 220Rn isotope has a half-life of 55 seconds and 219Rn isotope has a half-life of about 3.96 seconds. 222Rn decays into polonium-218(218Po), which in turn decays within minutes to lead-214 (214Pb), bismuth-214 (214Bi), and polonium-218 (218Po), which in turn decays within minutes to lead-214 (214Pb), bismuth 214 (214Bi), and polonium-214 (214Po)[3]. In particular, 222Rn poses a major concern in regard to radiation pollution and human health hazard [4, 5]. The radon gas can diffuse easily out of the soil surface into air or houses; it can be trapped in poorly ventilated houses and so its concentration can build up to higher levels. Although soil is considered to be the main source of indoor radon concentration, raw building materials (especially quartz, cement, etc.) can make a significant contribution to the level of natural radioactivity in closed spaces such as stores and badly-ventilated dwelling [6]. Moreover, the production rate of radon in dwellings depends on the concentration of radium content in the subsoil, building materials, and porosity as well as the density of the wall material [7, 8]. The emission of radon from building materials is found to be a function of ventilation as well as of the radium content in building materials. The nongaseous 222 Rn decay products are partially suspended in air as mixture of attached and unattached fractions and partially deposited on walls and furniture [9]. Over the past four decades, natural radiation exposure due to 222Rn and its progeny inside houses

  17. Removal of radon daughters from indoor air

    International Nuclear Information System (INIS)

    Jonassen, N.

    1985-01-01

    The internal radiological exposure of the general population is largely due to the airborne daughter products of radon and thoron, which are found in two states, attached to aerosols or unattached, of which the latter species according to several dose models have the highest radiological dose efficiency of the two. The radon daughters may be removed from indoor air by a series of processes like ventilation, filtration, plateout, and electrostatic deposition. Ventilation (with radon-free air) is, on the one hand, a very effective measure, but usually involves introduction of colder air, in variance with energy-saving efforts. Internal filtration will not affect the radon concentration but may reduce the level of daughter activities, roughly inversely proportional to the filtration rate. At the same time, however, filtration may also change the aerosol distribution and concentration of the air and, consequently, the partitioning of the radon daughters between the attached and unattached state. This, in turn, influences the rate of deposition of radon daughters both by diffusional plateout and as an effect of an electric field. Experiments are reported demonstrating reductions in the airborne potential alpha energy by factors of 4 to 5 by use of filtration rates of 3-4 times per hour. In case of low aerosol concentrations, however, the corresponding reduction in radiological dose to critical parts of the respiratory tract may be much smaller, due to the shift toward higher fractions of the radon daughters being in the unattached state caused by the filtration. The possibility of using electrostatic deposition of radon daughters is also discussed

  18. Measurement of radon permeability through polyethylene membrane using scintillation detector

    Energy Technology Data Exchange (ETDEWEB)

    Ashry, A.H.; Abou-Leila, M. [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Abdalla, A.M., E-mail: aymanabdalla62@hotmail.co [Department of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt); Department of Physics, Faculty of Sciences and Arts, Najran University, Najran, P.O. Box. 11001 (Saudi Arabia); Advanced Materials and Nano-Engineering Laboratory (AMNEL), Centre for Advanced Materials and Nano-Engineering (CAMNE), Najran University, Najran, P.O. Box. 11001 (Saudi Arabia)

    2011-01-15

    The permeability of Radon 222 through polyethylene membranes has been studied using activated charcoal technique. The permeability constant of Radon 222 through low-density polyethylene, linear low-density Polyethylene and high density polyethylene samples has been measured. There is a considerable agreement between the values obtained by our method and the method suggested by W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211], and SSNTD technique suggested by A. Hafez and G. Somogyi [1986. Determination of radon and thoron permeability through some plastics by track technique. Int. J. Radiat. Appl. Instrum. Nucl. Track Radiat. Meas. 12 (1-6), 697-700]. In this work Radon permeability through different polyethylene membranes has been measured using three different methods, i.e. solid state nuclear track technique, W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211]method and our proposed method. In addition to this, in this study, the diffusion coefficient of radon in charcoal as well as solubility of Radon in polyethylene membrane has been taken into consideration.

  19. Radon dosimetry for workers: ICRP's approach

    International Nuclear Information System (INIS)

    Marsh, James W.; Laurier, Dominique; Tirmarche, Margot

    2017-01-01

    The International Commission on Radiological Protection (ICRP) has recently published two reports on radon exposure; Publication 115 on lung cancer risks from radon and radon progeny and Publication 126 on radiological protection against radon exposure. A specific graded approach for the control of radon in workplaces is recommended where a dose assessment is required in certain situations. In its forthcoming publication on Occupational Intakes of Radionuclides (OIR) document, Part 3, effective dose coefficients for radon and thoron will be provided. These will be calculated using ICRP reference biokinetic and dosimetric models. Sufficient information and dosimetric data will be given so that site-specific dose coefficients can be calculated based on measured aerosol parameter values. However, ICRP will recommend a single dose coefficient of 12 mSv per working level month (WLM) for inhaled radon progeny to be used in most circumstances. This chosen reference value was based on both dosimetry and epidemiological data. In this paper, the application and use of dose coefficients for workplaces are discussed including the reasons for the choice of the reference value. Preliminary results of dose calculations for indoor workplaces and mines are presented. The paper also briefly describes the general approach for the management of radon exposure in workplaces based both on ICRP recommendations and the European directive (2013/59/EURATOM). (authors)

  20. Measurement of radon permeability through polyethylene membrane using scintillation detector

    International Nuclear Information System (INIS)

    Ashry, A.H.; Abou-Leila, M.; Abdalla, A.M.

    2011-01-01

    The permeability of Radon 222 through polyethylene membranes has been studied using activated charcoal technique. The permeability constant of Radon 222 through low-density polyethylene, linear low-density Polyethylene and high density polyethylene samples has been measured. There is a considerable agreement between the values obtained by our method and the method suggested by W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211], and SSNTD technique suggested by A. Hafez and G. Somogyi [1986. Determination of radon and thoron permeability through some plastics by track technique. Int. J. Radiat. Appl. Instrum. Nucl. Track Radiat. Meas. 12 (1-6), 697-700]. In this work Radon permeability through different polyethylene membranes has been measured using three different methods, i.e. solid state nuclear track technique, W. Arafa [2002. Permeability of radon 222 through some materials. Radiat. Meas. 35, 207-211] method and our proposed method. In addition to this, in this study, the diffusion coefficient of radon in charcoal as well as solubility of Radon in polyethylene membrane has been taken into consideration.

  1. An Alpha spectrometer for measuring radon daughter individual activity concentration; Spettrometro Alfa per la misura delle concentrazioni individuali in attivita' della progenie del radon

    Energy Technology Data Exchange (ETDEWEB)

    Berico, M.; Formignani, M. [ENEA, Div. Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche E. Clementel, Bologna (Italy); Mariotti, F. [Bologna Univ., Bologna (Italy). Dipt. di Fisica

    2001-07-01

    In the frame of the program of the Institute for Radiation Protection of ENEA, related to the evaluation of dose from radon and thoron progeny, an alpha spectrometer for the continuous air monitoring (CAM type) of radon and thoron has been realized. The constructive characteristics of the device are here presented together with energy and efficiency calibration. The device allows, by means of a screen type diffusion battery and a filter, to determinate the single radioactivity of each radionuclide of the progeny selecting them in relation to their diffusive behaviour (dichotomous particle size selection). The three-count filter method has been employed to measure the concentrations of {sup 218}Po, {sup 214}Pb and {sup 214}Bi in air. Radon and thoron effective doses using a dosimetric, instead of an epidemiologic approach, will be then evaluated. [Italian] Presso l'Istituto per la Radioprotezione, nell'ambito del programma di valutazione di dose da radon e' stato progettato e realizzato uno spettrometro alfa per il monitoraggio continuo in aria (CAM) della progenie del radon e del toron. Le caratteristiche costruttive dello strumento permettono, tramite l'utilizzo di batterie a diffusione a reti, di determinare l'attivita' individuale della progenie per diverse dimensioni granulometriche in particolare per la frazione attaccata e non al particolato amosferico con un taglio granulometrico di qualche nanometro. E' stato inoltre applicato un metodo spettrometrico a tre conteggi per il calcolo delle concentrazioni individuali della progenie del radon, {sup 218}Po, {sup 214}Pb and {sup 214}Bi, effettuando un conteggio alfa di {sup 218}Po e due conteggi alfa di {sup 214}Po. Tale informazione consentira' una valutazione della dose di radon utilizzando il modello dosimetrico in alternativa a quello epidemiologico.

  2. Thinking about Thoron and Thoron daughters: radiation studies and interpretations for a rare earths project

    International Nuclear Information System (INIS)

    Sonter, Mark; Hondros, Jim

    2016-01-01

    The emerging rare earths mining and processing industry involves projects which will invariably handle ores containing some levels of thorium, and to a lesser extent, uranium. The thorium levels which can be encountered range from tens of ppm up to percent levels. (Thorium content of pure monazite is in the range 5% to 8% or so.) This technical note focuses on the understanding of thoron releases into the air from thorium- bearing ores in situ and in process, and subsequent generation of thoron decay products in air, and the Potential Alpha Energy Concentration levels and dose estimations that result. It presents some theory, literature search results and a description of test work done on Nolans ore at Arafura's Darwin facility and in the field at Nolans Bore.

  3. Technical evaluation of a radon daughter continuous monitor in an underground uranium mine

    International Nuclear Information System (INIS)

    Bigu, J.; Grenier, M.

    1982-07-01

    An evaluation of a radon daughter monitor was carried out in an underground uranium mine. The monitor operates on continuous sampling and time integrating principles. Experimental and theoretical data were compared. Experimental results show that the monitor underestimates the Working Level, a fact which is partly attributed to plate-out of decay products in the monitor sampling head. However, a correction factor experimentally determined by standard calibration procedures can be programmed into the monitor to take into account losses by plate-out and other losses. Although the monitor was originally designed for radon daughters, it can equally be used in thoron daughter atmospheres and radon daughter/thoron daughter mixtures such as those encountered in some Canadian uranium mines. An analytical procedure is outlined to allow the calculation of Working Levels in radon daughter/thoron daughter atmospheres from the monitor α-count rate. The memory capability of the monitor should make it quite useful and flexible in underground and surface environments in the uranium mining industry

  4. Indoor radon measurements in Athens, Greece

    International Nuclear Information System (INIS)

    Proukakis, C.; Molfetas, M.; Ntalles, K.; Georgiou, E.; Serefoglou, A.

    1987-01-01

    A pilot study was carried out in order to measure air concentrations of radon 222 and 220 isotopes in Athenian houses, as a first step of a national survey in Greece. In this paper the authors deal with radon concentration in air and water and will rely on measurements conducted in Greece. (author)

  5. The radon

    International Nuclear Information System (INIS)

    1998-01-01

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

  6. Realisation of a calibration chamber for radon in the air and establishment of a system for measuring radon in water

    International Nuclear Information System (INIS)

    Sassi, Nedra

    2011-01-01

    Radon is a radioactive gas that is naturally produced from the decay of radium. The main source of radon found in the earth's crust caused by the presence of a series of uranium (222 isotope of radon) and a series of thorium (220 isotope of radon) therein. We have optimized a new radon calibration chamber by developing an electronic system controlled by a PIC 16F877 microcontroller type to manage the various functions of the room. Several electronic circuits were developed to manage multiple functions such as pressure, temperature and controls motors and solenoids. This system can also be interfaced with a computer through programs such as LabView or Matlab.

  7. Filtration approach to mitigate indoor Thoron progeny concentration

    International Nuclear Information System (INIS)

    Wang, J.; Meisenberg, O.; Karg, E.; Tschiersch, J.; Chen, Y.

    2010-01-01

    This study investigates filtration of air as potential mitigation method of thoron progeny exposure. The experiments were conducted in a model room (volume 7.1 m 3 ) which was equipped with a pump and an HEPA (high efficiency particulate air) filter. Filtration at a rate of 0.2, 0.4, 0.5 and 0.8 h -1 during 88 h proved an effective practice in reducing the total indoor thoron decay product concentration. The results indicate that 0.4-0.8 h -1 filtration rate had almost the same filtration efficiency in decreasing the total thoron EEC (equilibrium equivalent concentration) by 97% while 80% of total thoron EEC were reduced by 0.2 h -1 filtration rate; meanwhile, the unattached thoron EEC rose significantly by 190, 270, 290%, respectively under 0.4-0.8 h -1 filtration rate, whereas 0.2 h -1 filtration rate increased unattached thoron EEC by 40%. The aerosol number size distribution variation reveals that filtration operation removes smaller particles faster or earlier than the larger ones. The annual effective dose calculated was reduced by 91-92% at a filtration rate of 0.4-0.8 h -1 while 75% reduced at 0.2 h -1 filtration rate after 88 h filtration process. (authors)

  8. Indoor radon

    International Nuclear Information System (INIS)

    1997-12-01

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

  9. Spatial distribution of soil radon as a tool to recognize active faulting on an active volcano: the example of Mt. Etna (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Marco, E-mail: marco.neri@ct.ingv.it [Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2 - 95123 Catania (Italy); Giammanco, Salvatore [Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2 - 95123 Catania (Italy); Ferrera, Elisabetta; Patane, Giuseppe [Universita degli Studi di Catania, Dip. Scienze della Terra, Corso Italia, 52 - 95129 Catania (Italy); Zanon, Vittorio [Centro de Vulcanologia e Avaliacao de Riscos Geologicos - Universidade dos Acores, Rua Mae de Deus, 9501-801 Ponta Delgada (Portugal)

    2011-09-15

    This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquakes depth and intensity can give some hints on the source of gas and/or on fault dynamics. - Highlights: > We performed measurements of radon from soil carried out on Mt. Etna. > The sampled zone is characterized by the presence of numerous active faults. > Radon mapping reveal dangerous hidden faults buried by recent soil cover. > Our study gives some hints on the source of gas and on fault dynamics. > We recognized areas where radon activity represents a hazard to the population.

  10. Thoron (220Rn) in the indoor environment and work places

    Science.gov (United States)

    Ramachandran, T. V.; Sahoo, B. K.

    2009-08-01

    Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222Rn and its progeny, there was a great upsurge of interest in the measurement of 222Rn in the environment. Subsequently, considerable data is being generated on the levels of 222Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220Rn in indoors and workplace environment is scaree due to the genral perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon (222Rn), and thoron (220Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222Rn, 220Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232Th is being handled is being summarized. Methods of measurement and

  11. Thoron (220Rn) in the indoor environment and work places

    International Nuclear Information System (INIS)

    Ramchandran, T.V.; Sahoo, B.K.

    2009-01-01

    Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222 Rn and its progeny, there was a great upsurge of interest in the measurement of 222 Rn in the environment. Subsequently, considerable data is being generated on the levels of 222 Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220 Rn in indoors and workplace environment is scaree due to the general perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222 Rn, 220 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220 Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220 Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220 Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232 Th is being handled is being summarized. Methods of

  12. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

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

  13. Project Radon

    International Nuclear Information System (INIS)

    Ekholm, S.

    1988-01-01

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

  14. Dosimetry of radon, thorium and their progenies in the environment of a chemistry lab and crude in Zulia State, Venezuela; Dosimetria de radon, toron y sus progenies en el entorno de un laboratorio de quimica y crudo en el Estado Zulia, Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Pineda, L.; Viloria, T., E-mail: lendavaI22@hotmail.com, E-mail: lpineda@fing.luz.edu.ve, E-mail: tviloria63@yahoo.es [Universidad del Zulia, Maracaibo (Venezuela, Bolivarian Republic of). Departamento de Fisica; Palacios, D.; Sajo-Bohus, L., E-mail: sajobohus@gmail.com, E-mail: sanjuro.perdomo@gmail.com [Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of). Laboratorio de Fisica Nuclear

    2013-07-01

    The main objective of this study was to estimate the dose rate of inhalation and the annual contribution of effective dose in the mixed field of radon and thoron in the environment of laboratory chemicals and oil from Zulia State, Venezuela, due to manipulation and storage of oil samples and water production.

  15. Thoron in the air: assessment of the occupational dose

    International Nuclear Information System (INIS)

    Campos, Marcia Pires de

    1999-01-01

    The occupational dose due to inhalation of thoron was assessed through the committed effective dose and the committed equivalent dose received by workers exposed to the radionuclide at the nuclear materials storage site and the thorium purification plant of the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP). The radiation doses were performed by compartmental analysis following the compartmental model of the lung and biokinetic model of the lead, through the thoron equilibrium equivalent concentrations. These values were obtained by gamma ray spectrometry, total alpha count and alpha particle spectrometry of air samples glass fiber filters. The results of the thoron equilibrium equivalent concentration varied from 0.3 to 0,67 Bq/m 3 at the nuclear materials storage site and from 0.9 to 249.8 Bq/m 3 at the thorium purification plant. The committed effective dose due to thoron inhalation varied from 0.03 mSv/a to 0.67 mSv/a at the nuclear materials storage site and from 0.12 mSv/a to 6.0 mSv/a at the thorium purification plant. The risk assessment of lung cancer and fatal cancers for the workers exposed to thoron at the nuclear materials storage site and the thorium purification plant showed an increment for both risk cancer. (author)

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

    International Nuclear Information System (INIS)

    Tanner, A.B.

    1991-01-01

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

  17. 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)

  18. Variation of annual effective dose due to radon level in indoor air in Marwar region of Rajasthan, India

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Asha, E-mail: ashasachdeva78@gmail.com [Department of Applied Science, Ferozepur College of Engineering and Technology, Farozshah, Ferozepur-142052, Punjab (India); Mittal, Sudhir, E-mail: sudhirmittal03@gmail.com [Department of Applied Sciences, Punjab Technical University, Jalandhar-144601, Punjab (India); Mehra, Rohit [Department of Physics, Dr. B.R.Ambedkar National Institute of Technology, Jalandhar-144011 (India)

    2015-08-28

    In the present work, indoor radon and thoron measurements have been carried out from different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India using RAD7, a solid state alpha detector. The radon and thoron concentration in indoor air varies from 8.75 to 61.25 Bq m{sup −3} and 32.7 to 147.2 Bq m{sup −3} with the mean value of 32 and 73 Bq m{sup −3} respectively. The observed indoor radon concentration values are well below the action level recommended by International Commission on Radiological Protection (200-300 Bq m{sup −3}) and Environmental Protection Agency (148 Bq m{sup −3}). The survey reveals that the thoron concentration values in the indoor air are well within the International Commission on Radiological Protection (2005). The calculated total annual effective dose due to radon level in indoor air varies from 0.22 to 1.54 mSv y{sup −1} with the mean value of 0.81 mSv y{sup −1} which is less than even the lower limit of action level 3-10 mSv y{sup −1} recommended by International Commission on Radiological Protection (2005)

  19. Radon problems

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1985-01-01

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

  20. 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

  1. Time scale of hydrothermal water-rock reactions in Yellowstone National Park based on radium isotopes and radon

    International Nuclear Information System (INIS)

    Clark, J.F.; Turekian, K.K.

    1990-01-01

    We have measured 224 Ra (3.4 d), 228 Ra (5.7 yr), and 226 Ra (1620 yr) and chloride in hot spring waters from the Norris-Mammoth Corridor, Yellowstone National Park. Two characteristic cold-water components mix with the primary hydrothermal water: one for the travertine-depositing water related to the Mammoth Hot Springs and the other for the sinter-depositing Norris Geyser Basin springs. The Mammoth Hot Springs water is a mixture of the primary hydrothermal fluid with meteoric waters flowing through the Madison Limestone, as shown by the systematic decrease of the ( 228 Ra/ 226 Ra) activity ratio proceeding northward. The Norris Geyser Basin springs are mixtures of primary hydrothermal water with different amounts of cold meteoric water with no modification of the primary hydrothermal ( 228 Ra/ 226 Ra) activity ratio. Using a solution and recoil model for radium isotope supply to the primary hydrothermal water, a mean water-rock reaction time prior to expansion at 350degC and supply to the surface is 540 years assuming that 250 g of water are involved in the release of the radium from one gram of rock. The maximum reaction time allowed by our model is 1150 years. (orig.)

  2. Radon reduction

    International Nuclear Information System (INIS)

    Hamilton, M.A.

    1990-01-01

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

  3. New devices for radon measurements

    International Nuclear Information System (INIS)

    Sevostyanov, V.N.

    2004-01-01

    adding up to 30 minutes. The second new elaboration is 'Ramon-02-Automat' used to automatically monitor radon and thoron daughter decay products. The appliance enables the installation of diffusion battery to automatically measure unattached component as well as beta and gamma detectors in the mode of automatic activity measurement of beta and gamma active aerosols. The appliance can be used as a working man-pack means of measurement and also as fully automatic appliance capable of working without a re-charge for 30 days making measurements in a given time interval (above 800 measurements.) The appliance employs the method of alpha spectrometric measurements of air samples and the ribbon filter type NEL-4 for over 3,000 measurements as a filtering material. The ribbon filter is replaceable. All units in the appliance are controlled by a microprocessor. (author)

  4. Indoor-atmospheric radon-related radioactivity affected by a change of ventilation strategy

    International Nuclear Information System (INIS)

    Kobayashi, Tuneo

    2006-01-01

    The present author has kept observation for concentrations of atmospheric radon, radon progeny and thoron progeny for several years at the campus of Fukushima Medical University. Accidentally, in the midst of an observation term, i.e., February 2005, the facility management group of the university changed a strategy for the manner of ventilation, probably because of a recession: tidy everyday ventilation of 7:30-24:00 into shortened weekday ventilation of 8:00-21:00 with weekend halts. This change of ventilation manner brought a clear alteration for the concentrations of radon-related natural radioactivity in indoor air. The present paper concerns an investigation of the effect of the ventilation strategy on the indoor-atmospheric radon-related radioactivity. (author)

  5. A review of instrumentation for determination of radon and its daughters concentration

    International Nuclear Information System (INIS)

    Kurosawa, Ryuhei

    1989-01-01

    The aim of the review is to provide the aid for selection and understanding of the radon and its daughters measurement techniques which have been developed for radiation protection activities in various environments such as working of living environment. The practical purpose of the measurement for surveillance in environmental situation is the dose estimation for the public due to the inhalation of natural occurring radioactive materials. The techniques for the determination of radon and thoron concentratin by the active methods with the grab and continuous sampling, and also structures of radon monitors of various passive type are described. Explanation was made on the typical instruments for the determination of the potential alpha energy concentration (PAEC) of radon daughters by the various detecting systems such as solid state detector, and for the estimation of integrated PAEC in the various environments by the PAEC monitors using the cellulose nitrate film or TLD elements (author)

  6. Ventilation systems as an effective tool for control of radon daughter concentration in mines

    International Nuclear Information System (INIS)

    Dory, A.B.

    1981-10-01

    Introduced with a brief discussion of the key role of ventilation in controlling mine atmospheres, the effects of the design of the ventilation system on the control of radon daughter concentrations are illustrated with specific reference to Alcan's Director Mine, St-Lawrence, Nfld. (This fluorspar mine was found to have high radon concentrations due to mine water bringing in dissolved radon.) After a discussion of the health physics history of the mine, the various phases of the ventilation system design and the general results are detailed. The author draws some conclusions having general application to the design of any mine with a radon or thoron daughter concentration. These include minimizing the 'age' of the air; the need for continuous ventilation in all areas; the value of remote control and monitoring; and the benefits of mine pressurization

  7. Development and application of a model to calculate the distribution of radon in houses

    International Nuclear Information System (INIS)

    Haider, B.; Papamokos, E.; Ferron, G.; Peter, J.; Unverfaerth, L.

    1990-01-01

    In order to produce a radon profile of the examined houses, an electronic measuring process was used to determine the concentration of radon decomposition products. The measurements were made inside flats with the doors closed, in vertical air exchange between the cellars and the storeys of houses and in the cellar itself. The measured decomposition product and measured gas concentrations show that, apart from the cellar floor, part of the building material makes a considerable contribution to emanation of radon and thoron. It was found that a model for calculating the loading of the inhabitants of a house with radon is not yet available due to the complicated flat geometry and the activities of the inhabitants. (DG) [de

  8. A technical evaluation of the EDA radon gas continuous monitoring system

    International Nuclear Information System (INIS)

    Bigu, J.

    1979-04-01

    Extensive laboratory and underground tests were conducted with a radon gas continuous monitoring system built by EDA Instruments Inc. The system consists of several remote radon gas sensors linked via signal cables to a central control unit that fully controls the operation of the radon monitors. The system enables four operations to be performed: sampling, background, flush and bypass. The sequence and duration of these functions is programmable. Up to 20 functions in any desired pattern each lasting from 1 min to 23 hr 59 min can be programmed. Several programs were used during the experiments in order to obtain radon and thoron gas levels. The performance of the EDA system was quite satisfactory. It is suggested that ruggedization as well as some other modifications be introdouced into the system to: a) better withstand the harsh underground environment; and b) improve its performance

  9. A remote controlled system for continuous radon measurements to realize a monitoring network

    International Nuclear Information System (INIS)

    Roca, V.; Pugliese, M.; Venoso, G.; Roca, V.; Boiano, A.; D'Onofrio, A.; Pugliese, M.; Sabbarese, C.; Venoso, G.; D'Onofrio, A.; Sabbarese, C.

    2006-01-01

    R.A.M.O.N.A. (radon monitoring and acquisition) is a compact system for radon and climatic parameters monitoring. The instrument can perform alpha particles spectrometry with a resolution better than .5 %, so it is possible the discrimination of radon and thoron daughters. The development of battery operated electronics with integrated amplifier and micro controller makes the device applicable for in-lab and in-field measurements. Moreover, an ethernet interface allows to remotely drive the system and the download of acquired data. After a wide use of the prototype in laboratory, a lot of systems has been built and installed in some sites to carry out radon monitoring in soil. (authors)

  10. Radon compensation for alpha air monitoring systems

    International Nuclear Information System (INIS)

    Fleming, D.M.; Rising, F.L.; Zuerner, L.V.

    1975-01-01

    Continuous alpha air monitors, employing solid state detectors and single channel analyzers, for the detection of alpha particles of a specific energy have been available commercially for several years. The single channel pulse height analyzers provide good sensitivity to the isotope of interest and reject much of the unwanted activity from other isotopes such as naturally occurring radon and daughters. A small percentage of the radon daughters are degraded in energy by the air between the collecting filter and the diode to the extent that they coincide with energy of the isotope being measured and are counted as unwanted background. When 239 Pu is the isotope being measured the activity in the Pu channel resulting from radon is typically 2 percent of the total radon background. The majority of this unwanted background results from the degradation of the 6.0 MeV 218 Po (RaA) peak. This background is sufficient to cause instrument alarms during periods of radon activity. In attempts to reduce the frequency of false alarms, background subtraction circuits have been added as standard equipment to most of the alpha air monitors available on the market for the past several years. A method for calibrating these background subtraction circuits using a radon generator is described. (U.S.)

  11. Radon: current challenges in cellular radiobiology

    International Nuclear Information System (INIS)

    Brenner, D.J.

    1992-01-01

    Most of what is known about the hazards of radon daughters comes from epidemiological studies of miners. There are a few well defined areas in which in vitro research can complement such studies: More data on the relative effects of differing energy (LET) α-particles would help: (1) understand the significance of the depth of sensitive cells in the bronchial epithelium-which varies between individuals, as well as between smokers and non-smokers, and between miners and non-miners; (2) understand the relative hazards of radon and thoron daughters. Reliable methods for predicting high LET responses from low LET response, would enable Japanese A-bomb survivor data to be applied with confidence. Understanding the effects of single-particle traversals of cells relative to multiple traversals could allow reliable extrapolation of epidemiological miner data to low exposures. A better understanding of the nature of the interaction between tobacco and radiation damage would help predict the effect of radon on non-smokers. (author)

  12. Exposure to radon

    International Nuclear Information System (INIS)

    1988-01-01

    Part 3 is given of the Code of Practice approved by the UK Health and Safety Commission with the consent of the Secretary of State for the purpose of providing practical guidance with respect to the provisions of the Ionising Radiations Regulations 1985. Part 3 gives specific guidance on the application of the Regulations to certain work involving exposure to isotopes of radon and their decay products. Aspects covered in the Regulations include restriction of exposure, dose limits, controlled areas, radiation protection advisers and supervisors, dosimetry and area monitoring. (U.K.)

  13. Cigarette smoking increases radon working level exposures to all occupants of the smoker's home

    International Nuclear Information System (INIS)

    Johnson, R.H. Jr.; Rosario, A. Jr.

    1990-01-01

    This paper reports that the 1988 National Academy of Sciences report on radon health risks evaluated the combined effects of radon exposures and cigarettes on the lung cancer risk to smokers. This report showed that the risk of lung cancer is about 10 times greater for smokers than for nonsmokers at the same Working Level exposures. In 1986, the Surgeon General reported that 106,000 lung cancer deaths occurred among smokers. Therefore, the health risks of cigarettes alone or in combination with radon exposures are well recognized. What has not been studied is the effect of cigarette smoke on the Working Levels in homes that increases the exposure to radon decay products to all occupants, both smokers and nonsmokers. Preliminary studies in a radon chamber at Radon QC showed that the smoke from a single cigarette increased the Working Levels by a factor of five within four hours. Furthermore, the Working Levels remained at an elevated level for more than 24 hours. The equilibrium ratio of radon decay products to radon gas also went from about 14% up to 71%, with a slow decrease over 24 hours. Similar studies in the homes of a smoker and nonsmoker confirmed the laboratory observations. The studies in homes also showed the effects of thoron decay products

  14. Thoron (220Rn) decay products removal in poorly ventilated environments using unipolar ionizers: Dosimetric implications

    International Nuclear Information System (INIS)

    Joshi, M.; Sapra, B.K.; Khan, A.; Kothalkar, P.; Mayya, Y.S.

    2010-01-01

    Ionizers are proven to be effective in reducing the activity concentration of radon/thoron decay products in workplace environments. However, limited studies have been conducted on understanding the mechanism of removal and the related size dependency. This study demonstrates the feasibility of reducing the activity concentrations in small chambers and in room environments up to a factor of about 7. Field experiments in an uncontrolled ventilation area such as a thorium oxalate storage shed have also shown promising results with a possible concentration reduction by a factor of 4. However, these reductions have been necessarily associated with an increase (3-5 times) in the unattached fraction of the decay products which is a significant contributor to the lung dose. Owing to this, aspersions have been cast on the capability of the ionizers in reducing the effective dose. An attempt has been made here to estimate the effective doses over a wide range of parameters such as the initial unattached fraction, activity reduction ratio and the change in the unattached fraction, which get altered due to the use of ionizers. The study proves that for realistically achievable activity reduction ratios of about 3-5 with the employment of ionizers, the inhalation dose in workplace environments can be reduced by a factor of at least 4, as indicated by model calculations.

  15. Thoron ({sup 220}Rn) decay products removal in poorly ventilated environments using unipolar ionizers: Dosimetric implications

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, M.; Sapra, B.K.; Khan, A.; Kothalkar, P.; Mayya, Y.S., E-mail: bsapra@barc.gov.in [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085 (India)

    2010-11-01

    Ionizers are proven to be effective in reducing the activity concentration of radon/thoron decay products in workplace environments. However, limited studies have been conducted on understanding the mechanism of removal and the related size dependency. This study demonstrates the feasibility of reducing the activity concentrations in small chambers and in room environments up to a factor of about 7. Field experiments in an uncontrolled ventilation area such as a thorium oxalate storage shed have also shown promising results with a possible concentration reduction by a factor of 4. However, these reductions have been necessarily associated with an increase (3-5 times) in the unattached fraction of the decay products which is a significant contributor to the lung dose. Owing to this, aspersions have been cast on the capability of the ionizers in reducing the effective dose. An attempt has been made here to estimate the effective doses over a wide range of parameters such as the initial unattached fraction, activity reduction ratio and the change in the unattached fraction, which get altered due to the use of ionizers. The study proves that for realistically achievable activity reduction ratios of about 3-5 with the employment of ionizers, the inhalation dose in workplace environments can be reduced by a factor of at least 4, as indicated by model calculations.

  16. Performance test of passive radon–thoron discriminative detectors on environmental parameters

    International Nuclear Information System (INIS)

    Sorimachi, Atsuyuki; Tokonami, Shinji; Omori, Yasutaka; Ishikawa, Tetsuo

    2012-01-01

    This paper describes how humidity, wind and ambient aerosols in air influence the detection responses of passive detectors. Two types of alpha track detectors based on a passive radon ( 222 Rn)–thoron ( 220 Rn) discriminative measurement technique were used: the Raduet and Radopot detectors that were developed and calibrated by the National Institute of Radiological Sciences, Japan. The initial experiment showed that the infiltration rate of 220 Rn onto sponges with a high air exchange rate for the Raduet detectors was one third lower than that onto filters for the Radopot detectors. Little distinct dependence on humidity was observed for the 222 Rn detection responses of both detectors. For 220 Rn, the detection responses of both detectors for the high air exchange rate seemed to decrease slightly at high humidity conditions. The 220 Rn detection responses of the Radopot detectors had little influence from wind speed. The 220 Rn detection responses of the Raduet detectors for the high air exchange rate seemed to decrease at low wind speeds. Furthermore, there was little difference between the detection responses in the presence and absence of ambient aerosol particles because the ambient aerosols were filtered out during their passive diffusion through the sponges and filters for the Raduet and Radopot detectors, respectively.

  17. Etched track radiometers in radon measurements: a review

    CERN Document Server

    Nikolaev, V A

    1999-01-01

    Passive radon radiometers, based on alpha particle etched track detectors, are very attractive for the assessment of radon exposure. The present review considers various devices used for measurement of the volume activity of radon isotopes and their daughters and determination of equilibrium coefficients. Such devices can be classified into 8 groups: (i) open or 'bare' detectors, (ii) open chambers, (iii) sup 2 sup 2 sup 2 Rn chambers with an inlet filter, (iv) advanced sup 2 sup 2 sup 2 Rn radiometers, (v) multipurpose radiometers, (vi) radiometers based on a combination of etched track detectors and an electrostatic field, (vii) radiometers based on etched track detectors and activated charcoal and (viii) devices for the measurement of radon isotopes and/or radon daughters by means of track parameter measurements. Some of them such as the open detector and the chamber with an inlet filter have a variety of modifications and are applied widely both in geophysical research and radon dosimetric surveys. At the...

  18. Radon dose assessment in underground mines in Brazil

    International Nuclear Information System (INIS)

    Santos, T.O.; Rocha, Z.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B.; Oliveira, A.H.

    2014-01-01

    Underground miners are internally exposed to radon, thoron and their short-lived decay products during the mineral processing. There is also an external exposure due to the gamma emitters present in the rock and dust of the mine. However, the short-lived radon decay products are recognised as the main radiation health risk. When inhaled, they are deposited in the respiratory system and may cause lung cancer. To address this concern, concentration measurements of radon and its progeny were performed, the equilibrium factor was determined and the effective dose received was estimated in six Brazilian underground mines. The radon concentration was measured by using E-PERM, AlphaGUARD and CR-39 detectors. The radon progeny was determined by using DOSEman. The annual effective dose for the miners was estimated according to United Nations Scientific Committee on the Effects of Atomic Radiation methodologies. The mean value of the equilibrium factor was 0.4. The workers' estimated effective dose ranged from 1 to 21 mSv a -1 (mean 9 mSv a -1 ). (authors)

  19. Radon screening for XENON1T

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, Sebastian [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2015-07-01

    Radon with its isotope {sup 222}Rn is one of the dominant sources of internal background in liquid xenon detectors searching for low energetic rare events like WIMP-nucleon scattering. In my talk I briefly review the problem posed by {sup 222}Rn and motivate the screening strategy followed by XENON1T. I introduce the radon emanation technique making use of ultra low background proportional counters and present selected results obtained during the design and construction phases of XENON1T. Finally, I sketch advances in radon emanation assay techniques and give a short outlook on upcoming measurements.

  20. The HMGU thoron experimental house: A new tool for exposure assessment

    International Nuclear Information System (INIS)

    Tschiersch, J.; Meisenberg, O.

    2010-01-01

    A thoron experimental house was constructed in a laboratory room of Helmholtz Zentrum Muenchen to perform exposure studies of thoron and its decay products under controlled conditions. The single room house (7.1 m 3 ) was built from unfired clay stones and clay plaster. For the plaster of the inner side, the clay was mixed with granite powder enriched with 232 Th. The thoron inventory increased by this means to about 1700 Bq and the progeny potential alpha energy to 130 μJ inside the room. The instrumentation of the experimental house includes active and passive devices for thoron and thoron decay product measurement including attached and unattached progeny, for aerosol particle number and size measurement and characterisation of the climatic conditions. Various parameters as ventilation rate and aerosol concentration can be adjusted. Experiments performed in the experimental house demonstrate the experimental power of this new tool for indoor thoron exposure assessment 2010. (authors)

  1. Radon diffusion studies in air, gravel, sand, soil and water

    International Nuclear Information System (INIS)

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

    1993-01-01

    Radon isotopes are practically inert and have properties of gases under conditions of geological interest. During their brief lives their atoms are capable of moving from sites of their generation. Radon diffusion studies were carried out in air, gravel, sand, soil and water using silicon diffused junction electronic detector, Alphameter-400. Diffusion constant and diffusion length is calculated for all these materials. (author)

  2. Managing Radon in Schools

    Science.gov (United States)

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

  3. In situ measurements of thoron exhalation rate in Okinawa (Japan)

    International Nuclear Information System (INIS)

    Shiroma, Y.; Isa, N.; Hosoda, M.; Sorimachi, A.; Ishikawa, T.; Tokonami, S.; Furukawa, M.

    2010-01-01

    Thoron exhalation rates from the ground surface were measured at 57 sites on Okinawa Island (Japan), using a ZnS(Ag) scintillation detector equipped with photomultiplier. The arithmetic means ± SD, median ± SD, minimum and maximum of the rates (unit: Bq m -2 s -1 ) were estimated to be 1.9 ± 1.4, 1.6 ± 0.3, 0.04 and 6.2, respectively. The soils distributed on the island are generally classified into dark red soils, residual regosols, as well as red and yellow soils. While it was assumed that the soils were originated from the bedrock, recent studies suggested that the main material of dark red soils is the East Asian eolian dust. In the dark red soils area, the exhalation rate is relatively higher than that in the other areas. This suggested that the eolian dust was an enhancer for the environmental thoron concentration on Okinawa Island. (authors)

  4. Radon concentration of waters in Greece and Cyprus

    Science.gov (United States)

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

    2009-04-01

    Alpha Guard are connected via plastic radon proof tubes. Forced degassing of radon gas is performed by circulating the air in the set up with the use of a pump. Water sampling (to avoid radon escape) was driven by a strict protocol. Water taps were opened for 10 minutes before drawing the sample. Glass storage vessels of 200 to 1000 ml, with adjustment glass stoppers with standard NS 29/32 grounding, as well as sealing rings and granted security clamps for taper grounding, were completely filled slowly and immediately closed (to avoid the formation of air bubbles). Similar procedure (except tap opening) was followed for underground and surface waters. Laboratory measurements were performed at least one hour after drawing the sample in order to assure the full decay of any thoron content and to the minimum achievable time interval, so as the radon content to be the highest possible to allow higher precision. For the measurement the glass stopper was removed and immediately exchanged with the degassing cap. Afterwards water quantity was reduced to about half and measured. From the measurements, the mean annual equivalent dose rate (aEDr) delivered to stomach due to ingestion and the contribution to aEDr due to inhalation of radon in drinking water were calculated as using the EURATOM 2001 dose conversion factor (0.00144 mSv/Bq). Radon concentrations in drinking waters ranged between (1.1+/-0.5) Bq/L and (15+/4) Bq/L. Only three samples collected from the radon prone area of Arnea Chalkidikis presented high radon concentrations (120+/20 Bq/L, 320+/-40 Bq/L, 410+/-50 Bq/L). Radon concentrations in underground waters ranged between (1.2+/-0.7) Bq/L and (14.7+/-1.1) Bq/L. The corresponding concentration range in surface waters was (2.7+/-0.8) Bq/L and (24+/-6) Bq/L. The radon concentrations in thermal waters (some of which are used for drinking) were quite higher (in the range of (220+/-20) to (340+/-40) Bq/L). In both countries, no correlation of radon in underground waters

  5. Primary functions of the first Japanese large-scale facility for exposing small animals to radon

    International Nuclear Information System (INIS)

    Ishimori, Yuu; Tanaka, Hiroshi; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Kataoka, Takahiro; Sakoda, Akihiro

    2010-01-01

    The Japan Atomic Energy Agency (JAEA) and Okayama University have carried out the experimental animal study and its related studies since 2007 in order to examine the physiological effects of radon in detail. Thus, a radon test facility for small animals was developed in order to increase the statistical certainty of our animal tests. This paper illustrates the performances of that facility, the first large-scale facility of its types in Japan. The facility has a potential of approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups each of which consists of five independent cages. Different radon concentrations in each animal chamber group are available. The major functions of the facility controlling radon and avoiding thoron were shown theoretically and experimentally. The relative standard deviation of radon concentration at the highest concentration group was about 5%, although the lower concentration groups seemed to be affected by variations in background radon. (author)

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  7. 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.

  8. Mechanisms of radon injury

    International Nuclear Information System (INIS)

    Cross, F.T.

    1988-01-01

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

  9. 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

  10. Measurement of indoor radon concentration by CR-39 track detector

    International Nuclear Information System (INIS)

    Yamamoto, Masayoshi; Yoneda, Shigeru; Nakanishi, Takashi.

    1990-01-01

    A convenient and cheap method for measuring indoor radon ( 222 Rn) concentration with a CR-39 track detector is described. The detector consisted of two sheets of CR-39 enclosed separately in two plastic pots : one covered by a filter (cup method) and another no covering (bare method). The bare method was used here to supplement the cup method. To compare with the result of the CR-39 detector, alpha-ray spectrometry was carried out with a Si(Au) detector in a controlled radon exposure chamber. Indoor radon concentration measured in 133 houses in several districts of Ishikawa Prefecture have been found to range from 6 Bq/m 3 to as high as 113 Bq/m 3 with a median value of 24 Bq/m 3 . The problems to measure indoor radon concentration using the CR-39 detector are also discussed with emphasis on the position of setting the detector in the room and the possible thoron contribution to the detector. (author)

  11. Radon migration in the ground: a supplementary review

    International Nuclear Information System (INIS)

    Tanner, A.B.

    1980-01-01

    Water is the most important agent in enabling radon isotopes to escape from solid material: Water absorbs kinetic energy of the recoil atom of radon; it is an active agent in altering and hydrating mineral surfaces, thus enhancing their emanating power; and it decreases the adsorption of radon on mineral surfaces. Once in rock and soil pores, radon atoms migrate by diffusion and by transport in varying proportions. In diffusion and transport calculations, it is desirable to use the radon concentration in the interstitial fluid as the concentration parameter and to include porosity explicity. The transport component is important in dry, permeable soils in the upper layers but is much reduced below depths of several tens of meters. Research in disequilibriums in radionuclides of the uranium and thorium series suggests that much assumed migration of 222 Rn is, in fact, a more general migration of uranium and radium isotopes

  12. 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.

  13. Radon and health

    International Nuclear Information System (INIS)

    Chobanova, Nina

    2016-01-01

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

  14. 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.)

  15. Radon and its hazards

    International Nuclear Information System (INIS)

    Chang Guilan

    2002-01-01

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

  16. Radon in coal power plant areas

    International Nuclear Information System (INIS)

    Mauna, Traian; Mauna, Andriesica

    2006-01-01

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

  17. Comparison of a continuous working level monitor for radon daughters with conventional grab-sampling

    International Nuclear Information System (INIS)

    Bigu, J.; Grenier, M.

    1982-08-01

    An evaluation of a radon daughter monitor was carried out under laboratory controlled conditions. The monitor operates on continuous sampling and time integrating principles and was tested in conjunction with a newly designed, large radon/thoron room calibration facility. The monitor was tested under constant and rapidly fluctuating radiation conditions. Experimental data obtained with the monitor were compared with data obtained by conventional grab-sampling and with an automated radon daughter/thoron daughter 'grab-sampler'. The Working Level used in the tests ranged from less than 0.01 WL to approximately 10 WL. The measurements were carried out under low aerosol concentration (1 x 10 3 - 2 x 10 3 cm -3 , approximately) to study plate-out effects in the sampling head. Good agreement (within about 10 %) was found between the monitor, conventional grab-sampling and the automated grab-sampler. The monitor should prove quite flexible, useful and reliable for monitoring underground and surface environments in the uranium mining industry

  18. Radon and Lung Cancer Case-Control Study in Middle Ural

    International Nuclear Information System (INIS)

    Kirdin, I.A.; Lezhnin, V.L.; Yarmoshenko, I.V.; Ekidin, A.

    2001-01-01

    Full text: The pilot phase of radon and lung cancer case-control study has been performed in Karpinsk and Pervouralsk towns of Middle Ural region of Russia. The case group consists of 341 persons with lung cancer and living in that towns at least five previous years. The lung cancer diagnoses were carefully verified by instrumental techniques and 70% of its were morphologically validated. The persons for the control group (448) were chosen from the population living in that towns at least five years taking into account the age and sex. The special epidemiological questionnaire was developed which includes the items by the groups of factors as follow: clinical data, social factors, chronic lung diseases, life habit, tobacco smoking, alcohol drinking, diet preference etc. The epidemiological questionnaires were fulfilled for each member of case and control groups. Radon gas concentration and thoron equilibrium equivalent concentration measurements had been performed using nuclear track detectors and grab sampling accordingly in the dwellings of case and control groups members. By preliminary estimation the odds ratios are 1, 0.91, 1.2, 1.1 in the ranges of radon and thoron equilibrium equivalent concentration 0-6, 3-13, 13-36 and 36-370 Bq/m 3 respectively. The deeper and more rigorous analysis as well as different independent approaches will be discussed in the paper.(author)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  20. Radon programme: presence and future

    International Nuclear Information System (INIS)

    Hulka, J.

    2009-01-01

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

  1. Radon reduction in waterworks

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  2. How the schools can participate in measuring radon, thoron and radioactive fallout

    International Nuclear Information System (INIS)

    Storruste, A.; Larsen, E.

    1989-12-01

    The Chernobyl accident revealed that people in general have very little knowledge about radioactivity. The general knowledge should be improved rather cheaply and with small efforts through the introduction of a few experiments into the school curriculum. In the report some simple experiments of this kind are described. All the main apparatus needed are an ordinary GM counter and a vacuum cleaner. By using the same method at many schools, the data from the measurement of natural radioactivity variations in the air throughout the year could be usefully collected and collated. This would make the experiments more interesting than an experiments having no other purpose than the learning process itself. 12 refs.; 5 figs

  3. A case study of radon-thoron concentrations in dwellings around uranium deposit sites in Meghalaya

    International Nuclear Information System (INIS)

    Shaikh, A.N.; Ramachandran, T.V.; Eappen, K.P.; Mayya, Y.S.; Khan, A.H.; Puranik, V.D.; Hoda, S.Q.

    2004-01-01

    Measurement of 222 Rn and 220 Rn were carried out in a few houses of different construction types selected at 21 locations around uranium deposit sites at Meghalaya using Solid State Nuclear Track Detector (SSNTD) based dosimeter developed at the Bhabha Atomic Research Centre (BARC). It comprises of two cylindrical cups with slots for placing the detector films. The cups are designed for 222 Rn and 220 Rn gas estimations. Detector film used is 12 mm thick cellulose nitrate (LR -115 Type -II), of Kodak pathe. 222 Rn levels in these dwellings varied from 4.6 to 117.0 Bq m -3 with a GM of 19.4 Bq. m -3 (GSD 4.5), while 220 Rn varied from 5.0 to 123.0 Bq. m -3 with al GM of 16.6 Bqm -3 (GSD 2.0). The higher values were observed in building housing geological laboratories. (author)

  4. Radon and thoron concentrations in traditional cave dwellings and soil beds

    International Nuclear Information System (INIS)

    Shang Bing; Cui Hongxing; Li Hongzhou

    2003-01-01

    This paper describes the measured results of 222 Rn and 220 Tn concentrations in six cave dwellings and adobe Kang in Ning county of Gansu Province by using Rn-Tn solid-state nuclear track detectors. 222 Rn and 220 Tn concentrations are 161 and 307 Bq·m -3 (10 cm from soil wall), 99 and 158 Bq·m -3 (middle of the room) in cave dwellings, and 133 and 317 Bq·m -3 (5 cm above adobe Kang), 179 and 145 Bq·m -3 (20 cm above adobe Kang) on soil beds, respectively. 222 Rn and 220 Tn concentrations near the wall are higher than those obtained other place in the room. 222 Rn and 220 Tn concentrations above the adobe Kang are related to the distance from the surface of adobe Kang and heating situation. The residents sleep directly on the beds, especially for the children, the time staying on the adobe Kang are longer than other position. The dose of 222 Rn and 220 Tn from the traditional adobe Kang should be continuously studied

  5. Analysis of radon, uranium 238 and thorium 232 in potable waters: Dose to adult members of the Moroccan urban population

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Ouabi, H.; Merzouki, A.

    2007-01-01

    Uranium ( 238 U) and thorium ( 232 Th) concentrations as well as radon ( 222 Rn) and thoron ( 220 Rn) alpha-activities per unit volume have been measured inside various potable water samples collected from nineteen cities in Morocco by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). Measured radon alpha-activities ranged from (0.37 ± 0.02) Bq l -1 to (13.6 ± 1.10) Bq l -1 for the potable water samples studied. Alpha-activities due to radon from the ingestion of the studied potable water samples were determined in different compartments of the gastrointestinal system by using the ICRP compartmental model for radon. Annual committed equivalent doses due to radon were evaluated in the gastrointestinal compartments from the ingestion of the potable water samples studied. The influence of the target tissue mass, radon intake and alpha-activity integral due to radon on the annual committed equivalent doses in the gastrointestinal compartments was investigated

  6. Radon in geological medium

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  7. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

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

  8. Radon sump

    International Nuclear Information System (INIS)

    Wakeham, C.J.R.

    1992-01-01

    A radon sump which can be installed easily by unskilled labour and which is cheap to produce comprises a unit in the form of a box-like housing having one or more walls, a floor and a roof, and is preferably made from a synthetic plastics material, optionally reinforced with glass fibre or other reinforcing material, the housing having a plurality of inlets in its wall or walls and at least one outlet leading to a pipe spigot which is made in one piece with the housing. Alternatively, the housing is made in concrete, in 3 pieces (floor, wall, roof) with a knock-out portion which can be removed for insertion of an outlet pipe. (Author)

  9. Radon concentrations in residential housing in hiroshima and nagasaki

    International Nuclear Information System (INIS)

    Aoyama, Takashi; Radford, E.P.; Yonehara, Hidenori; Kato, Hiroo; Sakanoue, Masanobu.

    1993-05-01

    A survey of indoor radon ( 222 Rn) concentrations in Hiroshima and Nagasaki was carried out to assess the range of exposures expected among atomic-bomb survivors. Two hundred dwellings (100 from each city), chiefly of members of the Radiation Effects Research Foundation Life Span Study, were selected for this survey. We used two types of etched-track alpha-particle detectors: a Terradex detector (type SF) and an improved bare-track detector. Comparative measurements showed that although there was an adequate correlation between the values obtained using the two detectors, the geometric mean value for the bare-track detector was 45% lower than that for the Terradex detector. This difference was considered to be due to differences in the calibration methods and in the sensitivities of the detectors to thoron ( 220 Rn). The geometric mean values of the radon concentrations for 193 locations in Hiroshima and 192 locations in Nagasaki measured by Terradex SF detectors were 51.8 Bq/m 3 and 26.5 Bq/m 3 , respectively. The large difference is attributable to the different geological environments of the two cities. Factors correlating with the indoor radon concentrations were also studied. The geometric mean concentration was significantly higher in wooden houses with clay walls than in other types of house. This tendency was especially strong in Hiroshima. The difference between the estimated dose equivalents for exposure to radon decay products in dwellings in Hiroshima and Nagasaki during the last 30 years might amount to 0.8 Sv; however, no statistically significant difference was observed in lung-cancer mortality in the low-dose range in either city. Nevertheless, the indoor radon concentrations estimated in this survey could have a significant influence on the dose-response relationship for atomic-bomb exposure. (author)

  10. 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)

  11. 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)

  12. 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

  13. Radon survey techniques

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

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

  14. Radon in buildings

    International Nuclear Information System (INIS)

    Connell, J.J.

    1991-01-01

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

  15. Radon in workplaces

    International Nuclear Information System (INIS)

    Gooding, Tracy

    1995-01-01

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

  16. Personal factors affecting thoron exhalation from occupationally acquired thorium body burdens

    International Nuclear Information System (INIS)

    Stebbings, J.H.

    1985-01-01

    Thorium workers with thorium body burdens (primarily thoracic) above 0.7 nCi 224 Ra equivalent are shown to exhale about 15% of thoron produced in vivo, compared to 5% exhaled by subjects with body burdens in the range of 0.4 to 0.7 nCi 224 Ra. There was a false negative correlation between average adult daily cigarettes smoked and thoron exhalation. White blood cell counts that were about 85% of expected were observed in seven subjects exhaling greater than or equal to 100 pCi of thoron above predicted; no other variable examined showed a clear pattern of association. These differences in fractional thoron exhalation, and their consequences, are discussed. 3 references, 4 figures, 8 tables

  17. Indoor thoron studies along the northeast coast of Andhra Pradesh, India

    International Nuclear Information System (INIS)

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

    2013-01-01

    The beach sands of the northeast coast of Andhra Pradesh are well known for heavy metal mineralization. The process of extraction of the metals can enhance the natural background radiation levels and hence it is essential to establish the radiological base-line data to take necessary remedial action to preserve and protect the coastal environment. The assessment of indoor radioactivity levels has been carried out by choosing 13 villages long the northeast coast of Andhra Pradesh covering around 150 km from Vishakapattanam to Kalingapattanam. The present paper discusses the indoor thoron levels in the areas along the northeast coast of Andhra Pradesh. The SSNTD based twin chamber dosimeters were employed for the assessment of the concentration of thoron and its progeny levels. The average indoor thoron concentrations in this area are found to be 44.1 ± 28.2 Bq.m -3 . The inhalation dose due to thoron has been evaluated using equilibrium factors and discussed in detail. (author)

  18. Soil gas radon–thoron monitoring in Dharamsala area of north-west ...

    Indian Academy of Sciences (India)

    2National Center for Research on Earthquake Engineering, NARL, Taipei 106, Taiwan. ... The study described here is based on the measurements of soil gas radon–thoron concentrations performed ..... Himachal Pradesh, India; Nat. Hazards ...

  19. Radon in Soil and Tap Water in Lika-Senj County

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  20. Book of Abstracts - International Conference 'Radon in Environment', Zakopane, 10-14 May 2009

    International Nuclear Information System (INIS)

    Mazur, J.; Kozak, K.; Kobol, I.

    2009-04-01

    The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences has been organizing since 2000 the serial conferences, traditionally called RADON IN ENVIRONMENT. This is the first international meeting, two previous conferences (in 2000 and 2005) were national. The conference covers the following topics: · radon and thoron in air, water and soil, · modelling of radon transport, · geological aspects, · measurement techniques and interpretation of results, · techniques of reducing radon concentrations, · health aspects, · protection against radon risk, · uranium and thorium series, · NORM and TENORM elements in environment, · law regulations, · information policy. The Conference takes place in Zakopane (southern part of Poland, about 100 km distance from Krakow) at the conference and holiday centre '' ANTALOWKA ''. Zakopane, beautifully situated at the foot of the Tatra mountains, offers a chance to take advantage of outdoor recreation and to become acquainted with the unique folklore of the local mountaineers. We do hope that the conference will provide a forum to explore and discuss new scientific initiatives and all participants will benefit from this meeting. (author)

  1. Radon: Detection and treatment

    International Nuclear Information System (INIS)

    Loken, S.; Loken, T.

    1989-01-01

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

  2. 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

  3. Radon measurements in soils of Lagoa Real Uranium Province, BA: preliminary results

    International Nuclear Information System (INIS)

    Alves, James V.; Rocha, Zildete; Fuzikawa, Kazuo; Neves, J.M. Correia; Matos, Evando C. de

    2007-01-01

    The Cachoeira U mine in the Lagoa Real Uranium Province is the sole uranium producing mine in Brazil today. The necessity to increase ore reserves in the area is a reality, making any exploration efforts worthwhile to reach this objective. An exploration method based on radon detection in soil gas using the AlphaGUARD PQ2000PRO equipment was tested on two radiometric anomalies (no. 31 and no. 35) in the neighborhood of the mine. The results obtained indicated the technique as a helpful method for exploration of buried radioactive deposits. The method can not only discriminate thoron from radon but as a consequence indicate the original emanation source as well, making the method still more valuable in the search for uranium deposits. (author)

  4. Radon emanation from soils

    International Nuclear Information System (INIS)

    Markkanen, M.; Arvela, H.

    1992-01-01

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

  5. Diurnal variations of indoor radon progeny for Bangalore metropolitan, India

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  6. Overview of current radon and radon daughter research at LBL

    International Nuclear Information System (INIS)

    1983-01-01

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

  7. Study of the weekly irrigation cycle of a cultivated field in a semi-arid area (Marrakech region, Morocco) by using CR-39 and LR-115 II track detectors and radon as a natural tracer

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Essaouif, Z.

    2007-01-01

    Uranium ( 238 U) and thorium ( 232 Th) concentrations were measured in the soil of a cultivated field situated in a semi-arid area (Marrakech, Morocco) by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). The same track detectors were used for measuring alpha- and beta-activities due to radon and thoron gases emanating from the soil of the studied irrigated agricultural field. The influence of the humidity (soil water content), soil depth and climate conditions on the weekly irrigation cycle of the studied cultivated field was investigated by exploiting radon measurements

  8. Consumer's Guide to Radon Reduction

    Science.gov (United States)

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

  9. Swiss radon programme 'RAPROS'

    International Nuclear Information System (INIS)

    Zeller, W.

    1992-03-01

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

  10. Radon concentrations in residential housing in Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Yonehara, Hidenori; Aoyama, Takashi; Radford, E.P.; Kato, Hiroo; Sakanoue, Masanobu.

    1992-01-01

    A measurement of indoor radon ( 222 Rn) concentrations in Hiroshima and Nagasaki was carried out to examine an effect of the exposure on atomic bomb (A-bomb) survivors. Two hundred dwellings (100 from each city), chiefly of members of the Life Span Study population which is a fixed cohort studied by Radiation Effects Research Foundation (RERF), were selected for this survey. We used two types of alpha-track detector: a Terradex detector type SF and a bare-track detector improved by Yonehara et al. Comparative measurements showed that although there was an adequate correlation between the values obtained using the two detectors, the geometric mean value for the bare-track detector was 45% of that for the Terradex detector. This difference was considered to be due to differences in the calibration methods and sensitivities of the detectors to thoron ( 220 Rn). The arithmetic mean values of the radon concentrations for 193 locations in Hiroshima and 192 locations in Nagasaki measured by Terradex SF detector were 103 Bq m -3 and 40.6 Bq m -3 , respectively. The values at 100 locations in Hiroshima and at 93 locations in Nagasaki measured by the bare detector were 43.1. Bq m -3 and 13.6 Bq m -3 , respectively. The significant difference between the geometric mean values of the concentration in Hiroshima and Nagasaki measured by both methods was observed. The difference might be attributable to the different geological environments of the two cities. The difference between the estimated dose equivalents for exposure to radon daughters in dwellings in Hiroshima and Nagasaki over the last 30 years might amount to 0.4 or 0.8 Sv; however, no statistically significant difference was observed in lung cancer mortality in the low-dose range in either city. Nevertheless, the indoor-radon concentrations estimated in this survey could significantly influence the dose-response relationships for A-bomb exposure. (author)

  11. Thoron Mitigation System based on charcoal bed for applications in thorium fuel cycle facilities (part 1): Development of theoretical models for design considerations.

    Science.gov (United States)

    Sahoo, B K; Sudeep Kumara, K; Karunakara, N; Gaware, J J; Sapra, B K; Mayya, Y S

    2017-06-01

    Regulating the environmental discharge of 220 Rn (historically known as thoron) and its decay products from thorium processing facilities is important for protection of environment and general public living in the vicinities. Activated charcoal provides an effective solution to this problem because of its high adsorption capacity to gaseous element like radon. In order to design and develop a charcoal based Thoron Mitigation System, a mathematical model has been developed in the present work for studying the 220 Rn transport and adsorption in a flow through charcoal bed and estimating the 220 Rn mitigation factor (MF) as a function of system and operating parameters. The model accounts for inter- and intra-grain diffusion, advection, radioactive decay and adsorption processes. Also, the effects of large void fluctuation and wall channeling on the mitigation factor have been included through a statistical model. Closed form solution has been provided for the MF in terms of adsorption coefficient, system dimensions, grain size, flow rate and void fluctuation exponent. It is shown that the delay effects due to intra grain diffusion plays a significant role thereby rendering external equilibrium assumptions unsuitable. Also, the application of the statistical model clearly demonstrates the transition from the exponential MF to a power-law form and shows how the occurrence of channels with low probability can lower mitigation factor by several orders of magnitude. As a part of aiding design, the model is further extended to optimise the bed dimensions in respect of pressure drop and MF. The application of the results for the design and development of a practically useful charcoal bed is discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Radon and cancer

    International Nuclear Information System (INIS)

    2011-01-01

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

  13. Radon mitigation in schools

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  14. Leukaemia risks and radon

    International Nuclear Information System (INIS)

    Wolff, S.P.

    1991-01-01

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

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

    International Nuclear Information System (INIS)

    Ricardo, Carla Pereira; Oliveira, Arno Heeren de

    2011-01-01

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

  16. Radon therapy; Radon in der Therapie

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-01

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

  17. Radon-Instrumentation; Radon-Instrumentacion

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  18. Radon in dwellings

    International Nuclear Information System (INIS)

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

    1980-06-01

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

  19. Radon in buildings

    International Nuclear Information System (INIS)

    Ryan, N.M.; Finn, M.

    1995-01-01

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

  20. Radon in large buildings

    International Nuclear Information System (INIS)

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

    1993-01-01

    Over the past several years, considerable research has been devoted by the U.S. Environmental Protection Agency (USEPA) and others to develop radon sampling protocols for single family residences and schools. However, very little research has been performed on measuring radon in the work place. To evaluate possible sampling protocols, 833 buildings throughout the United States were selected for extensive radon testing. The buildings tested (warehouses, production plants and office buildings) were representative of commercial buildings across the country both in design, size and use. Based on the results, preliminary radon sampling protocols for the work place have been developed. (orig.). (5 refs., 3 figs.)

  1. Radon in Antarctica

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  2. The Pennsylvania radon story

    International Nuclear Information System (INIS)

    Gerusky, T.M.

    1987-01-01

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

  3. Radon atlas of Finland

    International Nuclear Information System (INIS)

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

    1997-11-01

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

  4. Radon dose and aerosols

    International Nuclear Information System (INIS)

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

    2000-01-01

    The equilibrium factor value (F) was measured in the NRPB radon chamber and the corresponding track density ratio (r = D/D 0 ) of bare (D) and diffusion (D 0 ) LR-115 nuclear track detectors was determined, as well as the regression equation F(r). Experiments with LR-115 nuclear track detectors and aerosol sources (burning candle and cigarette) were carried out in the Osijek University radon chamber and afterwards an empirical relationship between the equilibrium factor and aerosol concentration was derived. For the purpose of radon dose equivalent assessment, procedures for determining the unattached fraction of radon progeny were introduced using two nuclear track detectors. (author)

  5. Radon Measurements in Vojvodina

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  6. A new method to measure radon and thoron in flowing gases and its use to determine the thoron- content of atmospheric air

    Energy Technology Data Exchange (ETDEWEB)

    Jacobi, W.

    1963-11-15

    The measurement of Rn (Rn222) and Tn (Rn220) in air is of interest mainly for three purposes: distribution studies of the atmosphere; control of the inhalation hazard of workers in the uranium and thorium mining and milling industry; and, determination of the Ra226 or Th232-body burden. The paper describes methods used for measurement.

  7. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    International Nuclear Information System (INIS)

    Schmidt, Axel

    2008-01-01

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies

  8. Radon as a natural geochemical tracer for study of groundwater discharge into lakes

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Axel

    2008-06-27

    In the presented work the suitability of the naturally occurring radioactive noble gas isotope radon-222 for qualitative and quantitative description of groundwater discharge into lakes was studied. Basis of these investigations was the development of two innovative techniques for the on-site determination of radon in water. In the ex-situ radon measurement procedure, water from the source concerned is taken up in an exchange cell used for this purpose. Inside this cell, the radon dissolved in water is transferred via diffusion into a closed counter-flow of air and subsequently detected by a radon-in-air monitor. Where the in-situ radon determination is concerned, a module composed of a semipermeable membrane is introduced into a water column. Subsequently, the radon dissolved in the water body diffuses through the membrane into the corresponding air flow, by means of which it is transferred into a radon-in-air monitor and is detected. Combination of the developed mobile radon extraction techniques with a suitable and portable radon monitor allow the detection of radon-222 with sufficient accuracy (smaller 20 %) in groundwater as well as in surface waters, i.e., within a broad range of concentrations. Radon-222 was subsequently used to characterize groundwater discharge into a meromictic and a dimictic lake, i.e. two types of lake basically distinct from each other with respect to their water circulation properties were investigated. The use of the noble gas isotope radon-222 as a geochemical tracer makes the application of on-site detection techniques possible and that this in turn permits a rapid, reliable, and cost-effective assessment of groundwater discharge rates into lake water bodies.

  9. An unattended device for high-voltage sampling and passive measurement of thoron decay products

    Energy Technology Data Exchange (ETDEWEB)

    Gierl, Stefanie; Meisenberg, Oliver, E-mail: oliver.meisenberg@helmholtz-muenchen.de; Wielunski, Marek; Tschiersch, Jochen [Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg (Germany); Haninger, Thomas [Helmholtz Zentrum München, German Research Center for Environmental Health, Auswertungsstelle für Strahlendosimeter, Otto-Hahn-Ring 6, 81739 München (Germany)

    2014-02-15

    An integrating measurement device for the concentration of airborne thoron decay products was designed and calibrated. It is suitable for unattended use over up to several months also in inhabited dwellings. The device consists of a hemispheric capacitor with a wire mesh as the outer electrode on ground potential and the sampling substrates as the inner electrode on +7.0 kV. Negatively charged and neutral thoron decay products are accelerated to and deposited on the sampling substrates. As sampling substrates, CR39 solid-state nuclear track detectors are used in order to record the alpha decay of the sampled decay products. Nuclide discrimination is achieved by covering the detectors with aluminum foil of different thickness, which are penetrated only by alpha particles with sufficient energy. Devices of this type were calibrated against working level monitors in a thoron experimental house. The sensitivity was measured as 9.2 tracks per Bq/m{sup 3} × d of thoron decay products. The devices were used over 8 weeks in several houses built of earthen material in southern Germany, where equilibrium equivalent concentrations of 1.4–9.9 Bq/m{sup 3} of thoron decay products were measured.

  10. Deposition Pattern of Inhaled Thoron Progeny Size Distribution in Human Lung

    International Nuclear Information System (INIS)

    Mohamed, A.

    2005-01-01

    One of the important factors controlling the distribution of radiation dose to the different portions of the human respiratory tract is the deposition pattern of thoron progeny containing aerosol. Based on the activity size distribution parameters of thoron progeny, which were measured in El-Minia University, the deposition behavior of thoron progeny (attached and unattached) has been studied by using a stochastic deposition model. The measurements were performed with a wire screen diffusion battery and a low pressure cascade impactor (type Berner). The bronchial deposition efficiencies of particles in the size range of attached thoron progeny were found to be lower than those of unattached progeny. The effect of thoron progeny deposition by adult male has been also studied for various levels of physical exertion. An increase in the breathing rate was found to decrease the efficiencies with which inhaled progeny were deposited in the bronchi. As the ventilation rate increases from 0.54 to 1.5 m3 h-1, the average deposition efficiencies of airway generation 1 through 8 are expected to decrease by 22 % for 1.4 nm particles and by 38 % for 150 nm particles

  11. Public perceptions of radon risk

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  12. Measurements of indoor radon concentration in italian red cross workplaces: preliminary results

    International Nuclear Information System (INIS)

    Fontana, C.; Musumeci, R.G.; Valeriani, F.; Tonnarini, S.; Trevisi, R.

    2002-01-01

    In August 2000 in Italy the D.Lgs.241/00 law was passed to implement the 96/29 Euratom Directive (BSS Directive, EC 1996). D.Lgs.241/00 states that workers cannot be exposed to decay products of radon, thoron and gamma radiation at a level higher than action level. The law became effective January 1, 2001. Italian action level of 500 Bq/m3 is the annual average indoor radon concentration. Work activities in zones with greater probability of high indoor radon concentration have to be identified. According to the law, a Commission must establish criteria for clarifying areas at risk. The actual work of classification is then done by the regions. A three year time period was given to define areas at risk. As the normative still must be completed, the Italian Red Cross and the Italian National Institute for Occupational Prevention and Safety initiated this study both because the Red Cross has always been sensitive to health problems and also to offer the Commission further experimental data regarding radon in Italy

  13. Radon soil increases before volcano-tectonic earthquakes in Colombia

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  14. 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

  15. Radon and its measurement

    International Nuclear Information System (INIS)

    Penzo, Silvia

    2006-03-01

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

  16. MODEL RADIOACTIVE RADON DECAY

    Directory of Open Access Journals (Sweden)

    R.I. Parovik

    2012-06-01

    Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.

  17. Radon flux measurement methodologies

    International Nuclear Information System (INIS)

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

    1984-01-01

    Five methods for measuring radon fluxes are evaluated: the accumulator can, a small charcoal sampler, a large-area charcoal sampler, the ''Big Louie'' charcoal sampler, and the charcoal tent sampler. An experimental comparison of the five flux measurement techniques was also conducted. Excellent agreement was obtained between the measured radon fluxes and fluxes predicted from radium and emanation measurements

  18. Background concentrations of radon and radon daughters in Canadian homes

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  19. Variation of radon concentration in soil with different depth along the high background areas in Kerala

    International Nuclear Information System (INIS)

    Sonia, S.R.; Visnu Prasad, A.K.; Jojo, P.J.; Midhun, M.

    2016-01-01

    Radon is one of the naturally occurring radioactive gases in the environment produced from decay of radium isotopes, which are the decay product of 238 U, 232 Th and 235 U. Hence the concentration of uranium and thorium in the bed rock and soil materials determine the amount of radon produced in the soil. The radon produced in the soil migrates through the mechanism of diffusion and convection through pore spaces in the soil, fractures in the rock and along with weak zones such as shear faults, thrust etc. For some geological situations, radon migrates long distances from its place of origin and can be detected by alpha-particle recorders at the earth's surface. Concentration of radon in an area is governed by the radium content in the minerals, radon emanating power in the material, permeability of the soils and underlying rock, and moisture content in the soil

  20. Risks from radon

    International Nuclear Information System (INIS)

    Doll, Richard

    1992-01-01

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

  1. Radon in Syrian houses

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  2. Lessons from radon

    International Nuclear Information System (INIS)

    Nichols, M.

    1993-01-01

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

  3. Chemical properties of radon

    International Nuclear Information System (INIS)

    Stein, L.

    1986-01-01

    Radon is frequently regarded as a totally inert element. It is, however, a ''metalloid'' - an element which lies on the diagonal of the Periodic Table between the true metals and nonmetals and which exhibits some of the characteristics of both. It reacts with fluorine, halogen fluorides, dioxygenyl salts, fluoro-nitrogen salts, and halogen fluoride-metal fluoride complexes to form ionic compounds. Several of the solid reagents can be used to collect radon from air but must be protected from moisture, since they hydrolyze readily. Recently, solutions of nonvolatile, cationic radon have been produced in nonaqueous solvents. Ion-exchange studies have shown that the radon can be quantitatively collected on columns packed with either Nafion resins or complex salts. In its ionic state, radon is able to displace H + , Na + , K + , Cs + , Ca 2+ , and Ba 2+ ions from a number of solid materials. 27 refs., 6 figs

  4. Standardization of radon measurements

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  5. Radon in workplaces

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  6. 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

  7. Radon discrimination for work place air samples

    International Nuclear Information System (INIS)

    Bratvold, T.

    1994-01-01

    Gross alpha/beta measurement systems are designed solely to identify an incident particle as either an alpha or a beta and register a count accordingly. The tool of choice for radon identification, via decay daughters, is an instrument capable of identifying the energy of incident alpha particles and storing that information separately from detected alpha emissions of different energy. In simpler terms, the desired instrument is an alpha spectroscopy system. K Basins Radiological Control (KBRC) procured an EG ampersand G ORTEC OCTETE PC alpha spectroscopy system to facilitate radon identification on work place air samples. The alpha spectrometer allows for the identification of any alpha emitting isotope based on characteristic alpha emission energies. With this new capability, KBRC will explicitly know whether or not there exists a true airborne concern. Based on historical air quality data, this new information venue will reduce the use of respirators substantially. Situations where an area remains ''on mask'' due solely to the presence of radon daughters on the grab air filter will finally be eliminated. This document serves to introduce a new method for radon daughter detection at the 183KE Health Physics Analytical Laboratory (HPAL). A new work place air sampling analysis program will be described throughout this paper. There is no new technology being introduced, nor any unproven analytical process. The program defined over the expanse of this document simply explains how K Basins Radiological Control will employ their alpha spectrometer

  8. The importance of radon and its daughter products in environmental hygiene

    International Nuclear Information System (INIS)

    Schuettmann, W.

    1985-01-01

    Radon and its daughter products have recently been paid great attention as components of natural ionizing radiation. Their presence in houses and flats are focus of interest. The radon isotopes and their short-lived daughter products are represented briefly, followed by a condensed survey of the historical development of this topic. There are various reasons why this became topical only 80 years after radon had been proved in the atmospheric air. After the listing of the different sources of radon, a rough risk estimation is given regarding the role of radon in lung cancer incidence in the GDR. For environmental hygiene the houses with particularly high radon content of the air, the causes of which are given, are of special importance. Among these causes the ventilation of rooms is the factor having the greatest influence on the radon concentration. From the evidence of occasional, extremely high radon values efforts are derived to elaborate limits of radon concentrations in flats. Finally, the priority of the radon problem for environmental hygiene is pointed out by indicating the current interest of this problem in literature and at congresses. (author)

  9. The influence of the cigarette smoke pollution and ventilation rate on alpha-activities per unit volume due to radon and its progeny

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Flata, K.

    2003-01-01

    Alpha and beta activities per unit volume air due to radon, thoron and their decay products were evaluated in the air of various cafe rooms polluted by cigarette smoke. Both CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD) were used. Equilibrium factors between radon and its progeny and thoron and its daughters have been evaluated in the air of the studied cafe rooms. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of non-smoker members of the public. The influence of cigarette smoke pollution, ventilation rate and exposure time on committed equivalent dose in the respiratory systems of non-smokers was investigated. Committed equivalent doses ranged from 1.15x10 -11 -2.7x10 -7 Sv.y -1 /h of exposure in the extrathoracic region and from 0.8x10 -12 -1.7x10 -8 Sv.y -1 /h of exposure in the thoracic region of the respiratory tract of non-smokers

  10. Radon house doctor

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  11. Radon in public buildings

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  12. 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.

  13. Riddle of radon

    International Nuclear Information System (INIS)

    O'Riordan, M.

    1996-01-01

    Why is the most significant source of human exposure to ionising radiation - and one that is so easy to reduce - not accorded the attention it deserves from those engaged in radiological protection nor the action it requires from those affected by it at work or at home? There are, after all, clear indications that high levels of radon exist and firm strands of evidence that radon causes cancer. Some national and international authorities have even developed regulations and recommendations to limit exposures. But radon still lies in the penumbra of protection because proponents of intervention lack conviction and opponents are full of passionate intensity. Little wonder that citizens are confused! (Author)

  14. Radon affected areas: Scotland

    International Nuclear Information System (INIS)

    Miles, J.C.H.; Green, B.M.R.; Lomas, P.R.

    1993-01-01

    Board advice on radon in homes issued in 1990 specifies that areas of the UK where 1% or more of homes exceed the Action Level of 200 becquerels per cubic metre of air should be regarded as Affected Areas. Results of radon measurements in homes in the districts of Kincardine and Deeside and Gordon in Grampian Region and Caithness and Sutherland in Highland Region are mapped and used to delineate Affected Areas in these areas where required. The Scottish Office is advised to consider the desirability of developing guidance on precautions against radon in future homes. (author)

  15. Measuring your radon risk

    International Nuclear Information System (INIS)

    Mackmurdo, R.

    1994-01-01

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

  16. Assessment of thorium and thoron decay products in air - thorium plant

    International Nuclear Information System (INIS)

    Dhandayutham, R.; Gohel, C.O.; Shetty, P.N.; Savant, P.B.; Rao, D.V.V.

    1977-01-01

    For the evaluation of radiation dose to the lungs in a thorium plant, it is necessary to estimate the concentration of thorium, thoron and its daughter products in air. Methods employed in estimating thorium and its decay products and 'working level' are presented. (M.G.B.)

  17. 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

  18. The matter of radon

    International Nuclear Information System (INIS)

    O'Riordan, M.C.; O'Riordan, C.N.

    1992-01-01

    By comparison with the radiation doses from radon, the doses to individual members of the public and to the general community from nuclear activities are quite trivial. Doses from radon in some British homes exceed the statutory dose limit for nuclear workers;the collective dose from radon is two thousand times the value for nuclear discharges. And yet, too little attention - legal or otherwise - is paid to this radioactive pollutant. An attempt is made in this paper to compensate for the neglect. The origins, properties and harmful effects of radon are described. Measurements in homes and places of work are summarised. Voluntary and regulatory controls on exposure are elucidated. Questions of public administration, confidentiality of information and sale of property are discussed. Prospects for progress are assessed. (author)

  19. Radon - natural health threat

    International Nuclear Information System (INIS)

    Wrixon, Anthony

    1985-01-01

    Natural sources of radiation attract little attention, yet a survey has found radon gas in buildings at levels which put the occupants at some risk. The author wants safety standards set without undue delay. (author)

  20. Radon i danske lejeboliger

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Skytte Clausen, Louise

    I denne undersøgelse kortlægges radonindholdet i indeluften og det undersøges, hvordan indholdet af radon i indeluften er fordelt og spredes i en ejendom, og om det er muligt at pege på en bygningsdel eller en bygningskomponent som en spredningsvej for radon i boliger. Boligerne er lejeboliger og...... ligger i etageejendomme, kæde- og rækkehuse tilhørende bygningstyper opført fra 1850 og frem. De udvalgte ejendomme ligger i områder af landet, hvor der ved tidligere undersøgelser har vist sig at være en stor andel af huse med et højt indhold af radon i indeluften. Koncentrationen af radon er målt over...

  1. ROE Radon Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The polygon dataset represents predicted indoor radon screening levels in counties across the United States. These data were provided by EPA’s Office of Radiation...

  2. Radon in workplaces

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  3. 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)

  4. 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)

  5. Radon-Instrumentation

    International Nuclear Information System (INIS)

    Moreno y Moreno, A.

    2003-01-01

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

  6. Personal radon daughter dosimetry

    International Nuclear Information System (INIS)

    Stocker, H.

    1979-12-01

    The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

  7. Radon in housing

    International Nuclear Information System (INIS)

    1984-04-01

    The enclosed material deals with the substantial efforts made until now to control the levels of radon in Sweden dwellings. It is meant as a source material for the several publications which have emerged from the National Institute of Radiation Protection in Stockholm during 1983 and 1984. The first document is a translation of chapter 16, the deliberations of the Swedish Radon Commission, appointed by the government in 1979. Comments on the report of the commission were solicited before 1 October, 1983. (author)

  8. Radon og boligen

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

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

  9. Radon in Croatian spas

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  10. Predicting radon/radon daughter concentrations in underground mines

    International Nuclear Information System (INIS)

    Leach, V.A.

    1984-01-01

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

  11. Radon in the Houses of Virovitica and Podravina County

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  12. 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

  13. Radon as a hydrological indicator

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-02-01

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

  14. Radon emanometry in active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M. (CNRS, IN2P3, BP45/F63170 Aubiere (France)); Cejudo, J. (Instituto Nacional de Investigaciones Nucleares, Mexico City)

    1984-01-01

    Radon emission measurements from active volcanoes has, since 1981, been continuously measured at monitoring stations in Mexico and in Costa Rica. Counting of etched alpha tracks on cellulose nitrate LR-115 detectors give varying results at the several stations. Radon emanation at Chichon, where an explosive eruption occurred in 1982, fell down. Radon detection at the active volcano in Colima shows a pattern of very low emission. At the Costa Rica stations located at Poas, Arenal and Irazu, the radon emanation shows regularity.

  15. Radon risk in residential buildings

    International Nuclear Information System (INIS)

    Niewiadomski, T.

    1996-01-01

    The author discusses the risk related to the inhalation of radon decay products. This products are the cause of almost the half of the doses absorbed by the people. The concentration of radon in buildings is much higher than in the open areas and its country average in Poland is 50 Bq/m 3 . It is difficult to predict the concentration of radon in the building without measurement. Author concludes that there are technical means to decrease radon concentration in buildings

  16. Radon in the workplace

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  17. Measurements of seasonal and daily radon daughter concentration fluctuations in National Park Service caves

    International Nuclear Information System (INIS)

    Yarborough, K.A.

    1977-01-01

    The National Park Service (NPS) is studying levels of airborne alpha radiation from radon and thoron in all NPS administered caves in which tours for visitors are regularly conducted. The NPS research has the dual but complementary objectives of safeguarding health at the NPS administered caves, and to develop data on alpha radiation levels and on natural airflows in NPS caves. The results reported here for NPS caves describe concepts hypothesized for the objectives. In addition the data can be used by various agencies to clarify health standards for exposures to low airborne alpha radiation levels in cave environments. These results show daily and seasonal trends and the influence of natural ventilation by air circulation for each cave investigated

  18. Radon in the indoor environment

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    1998-01-01

    The objectives of R and D on radon in the indoor environment at SCK-CEN is to (1) to investigate the deposition of radon progeny in the human respiratory tract by means of direct measurements as a function of aerosol conditions; to assess the radon concentrations in buildings retrospectively with volume traps. Progress and main achievements in 1997 are reported on

  19. Radon in the indoor environment

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    1998-01-01

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

  20. Emission of radon from soil

    International Nuclear Information System (INIS)

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

    1980-03-01

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

  1. Natural radium and radon tracers to quantify water exchange and movement in reservoirs

    Science.gov (United States)

    Smith, Christopher G.; Baskaran, Mark

    2011-01-01

    Radon and radium isotopes are routinely used to quantify exchange rates between different hydrologic reservoirs. Since their recognition as oceanic tracers in the 1960s, both radon and radium have been used to examine processes such as air-sea exchange, deep oceanic mixing, benthic inputs, and many others. Recently, the application of radon-222 and the radium-quartet (223,224,226,228Ra) as coastal tracers has seen a revelation with the growing interest in coastal groundwater dynamics. The enrichment of these isotopes in benthic fluids including groundwater makes both radium and radon ideal tracers of coastal benthic processes (e.g. submarine groundwater discharge). In this chapter we review traditional and recent advances in the application of radon and radium isotopes to understand mixing and exchange between various hydrologic reservoirs, specifically: (1) atmosphere and ocean, (2) deep and shallow oceanic water masses, (3) coastal groundwater/benthic pore waters and surface ocean, and (4) aquifer-lakes. While the isotopes themselves and their distribution in the environment provide qualitative information about the exchange processes, it is mixing/exchange and transport models for these isotopes that provide specific quantitative information about these processes. Brief introductions of these models and mixing parameters are provided for both historical and more recent studies.

  2. Radon in Norwegian dwellings

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  3. Measurements of indoor radon and radon progeny in Mexico City

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  4. The householders' guide to radon

    International Nuclear Information System (INIS)

    1988-06-01

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

  5. Radon surveys and their implications

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  6. Radon in soil gas

    International Nuclear Information System (INIS)

    Rector, H.E.

    1990-01-01

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

  7. Radon: a bibliography

    International Nuclear Information System (INIS)

    Lepman, S.R.; Boegel, M.L.; Hollowell, C.D.

    1981-01-01

    The Lawrence Berkeley Laboratory, with the support of the Department of Energy, has developed a computerized database to manage research information in the area of building ventilation and indoor air quality. This literature survey contains references pertaining to the physical properties of radon and its daughters, instrumentation for their measurement, health effects, surveys and measurements, and regulatory information. The references in the bibliography are sequenced in alphabetical order and abstracts are included when supplied by the author. The objective of this report is to disseminate the bibliographic references compiled at the laboratory relating to radon research portion of the program. Interested database users are encouraged to contact the laboratory to receive instructions for direct database acess. A flyer describing the database is supplied at the end of the bibliography and a brief overview of the Radon Research porgram is given

  8. Radon: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Lepman, S.R.; Boegel, M.L.; Hollowell, C.D.

    1981-01-01

    The Lawrence Berkeley Laboratory, with the support of the Department of Energy, has developed a computerized database to manage research information in the area of building ventilation and indoor air quality. This literature survey contains references pertaining to the physical properties of radon and its daughters, instrumentation for their measurement, health effects, surveys and measurements, and regulatory information. The references in the bibliography are sequenced in alphabetical order and abstracts are included when supplied by the author. The objective of this report is to disseminate the bibliographic references compiled at the laboratory relating to radon research portion of the program. Interested database users are encouraged to contact the laboratory to receive instructions for direct database acess. A flyer describing the database is supplied at the end of the bibliography and a brief overview of the Radon Research porgram is given.

  9. Alpha scintillation radon counting

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.

    1977-01-01

    Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

  10. Radon depth migration

    International Nuclear Information System (INIS)

    Hildebrand, S.T.; Carroll, R.J.

    1993-01-01

    A depth migration method is presented that used Radon-transformed common-source seismograms as input. It is shown that the Radon depth migration method can be extended to spatially varying velocity depth models by using asymptotic ray theory (ART) to construct wavefield continuation operators. These operators downward continue an incident receiver-array plane wave and an assumed point-source wavefield into the subsurface. The migration velocity model is constrain to have longer characteristic wavelengths than the dominant source wavelength such that the ART approximations for the continuation operators are valid. This method is used successfully to migrate two synthetic data examples: (1) a point diffractor, and (2) a dipping layer and syncline interface model. It is shown that the Radon migration method has a computational advantage over the standard Kirchhoff migration method in that fewer rays are computed in a main memory implementation

  11. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

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

  12. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

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

  13. Water radon anomaly fields

    Energy Technology Data Exchange (ETDEWEB)

    Yin, H.

    1980-01-01

    A striking aspect of water radon levels in relation to earthquakes is that before the Tangshan quake there was a remarkable synchronicity of behavior of many wells within 200 km of Tangshan. However, for many wells anomalous values persisted after the earthquake, particularly outside the immediate region of the quake. It is clear that radon may be produced by various processes; some candidates are pressure, shear, vibration, temperature and pressure, mixing of water-bearing strata, breakdown of mineral crystal structure, and the like, although it is not clear which of these are primary. It seems that a possible explanation of the persistence of the anomaly in the case of Tangshan may be that the earthquake released strain in the vicinity of Tangshan but increased it further along the geological structures involved, thus producing a continued radon buildup.

  14. Dry radon gas generator

    International Nuclear Information System (INIS)

    Vandrish, G.

    1979-10-01

    A radon gas standard with a source strength of 120037 pCi capable of delivering 121 pCi of radon gas successively to a large number of cells has been developed. The absolute source strength has been calibrated against two radium solution standards and is accurate to 4 percent. A large number of cells (approxiiately 50) may be calibrated conveniently on a daily basis with appropriate corrections for sequential changes in the amount of gas delivered, and a correction for the growth of radon in the standard on successive days. Daily calibration of ten cells or less does not require these corrections. The standard is suitable for field use and the source emanation rate is stable over extreme temperatue and pressure ranges and over six months

  15. Radon: an environmental pollutant

    International Nuclear Information System (INIS)

    Mills, W.A.

    1979-01-01

    Radiological concerns with the disposal and use of mining and milling residues have heightened to the point that federal agencies are asking or being asked to formulate new regulactions for controlling radon daughters from a variety of sources - radioactivity previously considered to be part of our natural environment. Based on information derived from epidemiologic studies of underground miners, particularly uranium miners, the health impact on the general public is being projected. Depending on the assumptions made, these projections vary widely. Because of these variations in health risks, decisions on control measures have even wider implications on economic and social considerations. Thus the question: is radon an environmental pollutant. While not fully answering the question, recognizing the uncertainties in assessing and controlling radon daughters can put the question in better perspective

  16. Radon Research Program, FY 1991

    International Nuclear Information System (INIS)

    1992-03-01

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

  17. Project radon final report

    International Nuclear Information System (INIS)

    Ekholm, S.; Rossby, U.

    1990-01-01

    The main radiation problem in Sweden is due to radon in dwellings. At the Swedish State Power Board, R, D and D about radon has been going on since 1980. The work has concentrated on the important questions: How to find building with enhanced radon levels?; How to accurately decide on measures that will give adequate cleaning-up results, using appropriate measurement procedures; What cleaning-up effect is possible to achieve with an electro-filter?; and What cleaning-up effects are possible to achieve with different types of ventilation systems? The R, D and D-work, has been pursued in cooperation with universities of technology in Denmark and Finland, equipment manufacturers, consultants and authorities concerned. It was decided in December 1986 to give an offer to some SSPB-employees to investigate the radon situation of their dwellings, in order to test methods of measurement and cleaning-up under realistic conditions and to develop the methods to commercial maturity. The investigation was named 'Project Radon' and was carried out in three years with costs amounting to 1 M dollars. During the project less comprehensive radon measurements, named 'trace-measurements' were undertaken in about 1300 dwellings and more elaborate measurements, leading to suggestions of actions to be taken, in about 400 dwellings. Out of the suggestions, about 50 are carried out including control measurement after actions taken. The control measurement have shown that the ability to suggest appropriate actions is very successful - in just one case was a minor additional action necessary. The high reliability is achieved by always doing elaborate measurements before suggested mitigation method is decided on. (authors)

  18. 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)

  19. 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.

  20. Radon mitigation in schools

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  1. Radon assay for SNO+

    Energy Technology Data Exchange (ETDEWEB)

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)

    2015-12-31

    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.

  2. Radon measurements in Greece

    International Nuclear Information System (INIS)

    Georgiou, E.; Ntalles, K.; Molfetas, M.; Athanassiadis, A.; Proukakis, C.

    1988-01-01

    Studies of radon concentration in greek spas, in a cave, in constituents of the greek cement, in building materials in Greece and in greek mines have been published. Some preliminary studies of radon concentration in greek dwellings have been published. In order to get an idea of the problem in Greece we decided to carry out a national survey. Two different sites were selected: Athens, where domicile about 40% of the greek population and Domatia, a small village in northern Greece 600Km from Athens, located in an area known to have soil with increased uranium concentrations

  3. Estimation of thorium lung burden in mineral separation plant workers by thoron-in-breath measurements

    International Nuclear Information System (INIS)

    Radhakrishnan, Sujata; Sreekumar, K.; Tripathi, R.M.; Puranik, V.D.; Selvan, Esai

    2010-01-01

    The Minerals Separation Plant (MSP) of M/s Indian Rare Earths Ltd. (IREL) at Manavalakurichi in Tamil Nadu is engaged in the processing of beach sands to separate ilmenite, monazite, rutile, sillimanite, garnet, and zircon. The present study has been carried out on nearly 200 workers of the mineral separation plant who are chronically exposed to the radiation hazards. Measurement of thoron in the exhaled breath of the worker is an indirect method of estimating the body burden with regard to Th

  4. 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

  5. Groundwater flow analysis using radon-222 existing in environment as an indicator

    International Nuclear Information System (INIS)

    Komae, Takami

    1996-01-01

    Several kinds of isotopes have been used to trace water movement in the hydrology including surface and ground water as indicators. But those are not effective to analyze the contaminant movement with groundwater though short distance in short time owing to long life. Radon ( 222 Rn) existing in environment was chosen for this purpose as an short-lived indicator. Radon is a radioactive gas, with a half life of 3.8 days, generated from radium ( 226 Ra) in strata. Radon concentration in groundwater increases to reach an equilibrated value within about three weeks after infiltrating underground. The equilibrated concentration becomes an own value of the aquifer depending on the radium content, the grain size and porosity of aquifer. The characteristic makes it able to identify aquifers and sub basins. Since radon concentration in groundwater is 100 to 1000 times as high as that in surface water, groundwater and surface water interaction is quantitatively analyzed. A liquid scintillation counter was employed to measure radon concentration after extracting radon in water to toluene. We applied those advantage of radon-222 to various field investigations and discussed the applicability. It was really possible to analyze the groundwater flow. Monitoring radon concentration in pumped water, occurrences of squeeze and leakage from the different aquifer were detected. Main aquifer was easily determined from the vertical distribution of radon concentration in bore hole. In the injection test using surface water, the spread of injected water was confirmed by the decrease of radon concentration in bore hole water. The radon method was useful to analyze the dam leakage, effluent seepage of groundwater in river, influent seepage of river water underground, and groundwater recharge with irrigation water through unsaturated zone. (author)

  6. Radiological safety assessment of Thoron inhalation hazards during DDU handling at UMP, Trombay

    International Nuclear Information System (INIS)

    Shailesh, M.; Belhe, M.S.; Malti; Narayani, K.; Satpati, S.K.

    2012-01-01

    Uranium Extraction Division, Bhabha Atomic Research Centre, Mumbai has been producing nuclear grade uranium metal from Ammonium di-uranate received from IRE to meet the fuel requirement of research reactors of Bhabha Atomic Research Centre at Uranium Metal Plant (UMP) in Trombay. In UMP, uranium oxide powder (U 3 O 8 and UO 3 ) is first reduced to uranium dioxide in reduction reactor and is converted to uranium tetra fluoride in hydro fluorination reactor. After removing moisture and acid vapour in expulsion area, reduction of uranium tetrafluoride is carried out with magnesium in magnesio-thermic reduction (MTR) reactor, pure uranium metal ingot with magnesium fluoride slag is produced. Finally natural uranium ingot is separated from slag in ingot discharging area. However deeply depleted uranium (DDU) metal was produced from uranium oxide (reprocessed uranium) received from PREFRE, Tarapur, as a special campaign. External radiation hazards are not dominant during the processing of natural uranium in uranium metal Plant. However it was observed that during processing of DDU metal, external and internal hazards are significant because of daughter products of thoron. Inhalation dose due to thoron was found less during charging of UO 3 powder operation than ingot discharge operation because of pneumatic powder transport system used for charging operation. It is estimated that after introduction of new blower system in different powder handling operation areas, the potential effective inhalation dose due to thoron inhalation may get reduced by 60% - 80%

  7. 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/

  8. Is radon emission in caves causing deletions in satellite DNA sequences of cave-dwelling crickets?

    Directory of Open Access Journals (Sweden)

    Giuliana Allegrucci

    Full Text Available The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA. Radon concentration in the analyzed caves ranged from 221 to 26,000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.

  9. 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

  10. Isotopic and geochemical precursors of earthquakes and volcanic eruptions

    International Nuclear Information System (INIS)

    1993-11-01

    Radon 222 seems to be one of the most promising precursors and is the tracer for which more data are available: according to statistics elaborated in China, 70% of earthquakes are preceded by radon anomalies detectable in soil, air and/or in groundwater. Also other changes of the fluid chemical composition and variations of 3 He/ 4 He, 2 H/ 1 H, 13 C/ 12 C, 18 O/ 16 O isotopic ratios have been detected. Among these indicators one can mention variations in concentration and/or isotopic ratios of hydrogen, helium, carbon, oxygen, neon, radon, radium and uranium. Refs, figs, tabs

  11. Indoor exposure to radon and its health effects

    International Nuclear Information System (INIS)

    Loskiewicz, J.

    1997-10-01

    Radon (Rn-222) is a noble radioactive gas which originates during U-238 series decay. As a noble gas it is not reacting with soils and building materials and therefore is showing large mobility due to its half-life of 3.82 days. It decays through alpha emission and is producing other radioactive isotopes (Po-218, Bi-214 etc.) which are solid. The migration of radon and its decay products can be in unattached form or attached to aerosols. The size of aerosol particles is important for adhesion coefficient value and for inhalation probability by human respiratory system. The unattached radon is penetrating more easily into lung space and there it may decay into radioactive and alpha emitting solid isotopes. The emitted alpha particle can damage sensitive cells. An alpha particle that penetrates that epithelial cells can deposit enough energy in a cell to kill or transform it. The transformed cell, alone or through interaction with some other agent, has the potential to develop eventually into a lung cancer. The data on risk of a lung cancer occurrence for high and medium concentrations of radon in the air will also be presented. (author)

  12. A new method for the determination of radium-228, thorium-228, and radium-224 in groundwaters via thoron (radon-220)

    International Nuclear Information System (INIS)

    Smith, M.R.; Lautensleger, A.W.; Laul, J.C.

    1988-01-01

    An improved method for determining radium and thorium from the 232 Th decay series has been developed which measures the activity of 220 Rn as an assay of its parents. Although some ingrowth corrections and minor separation procedures for Th are required, the results to date show that the dynamic counting of 220 Rn via de-emanation and alpha counting by the alpha-scintillation method is preferable. The method for lower limit detection depends on the emanation rate. (author) 3 refs.; 6 figs

  13. Study of α-energy discrimination in CR-39 track etch detectors for use as a radon/thoron dosemeter

    International Nuclear Information System (INIS)

    Kandaiya, S.; Al-Najjar, S.A.R.; Piesch, E.

    1988-01-01

    The properties of CR 39 nuclear track detectors were evaluated for their α-energy discrimination up to 8.77 MeV using a combination of chemical-electrochemical track revealing techniques. Using three field strengths, α-energy discrimination by ECE track diameter and track density as a function of chemical pre-etching time were studied. α-energy spectra using different irradiation geometries were then evaluated using the optimum conditions and then compared with those obtained form other techniques. (author)

  14. Radon campaigns. Status report 2008

    International Nuclear Information System (INIS)

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

    2008-12-01

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

  15. Publications about Radon

    Science.gov (United States)

    There is no known safe level of exposure to radon. EPA strongly recommends that you fix your home if your test shows 4 picocuries (pCi/L) or more. These publications and resources will provide you with the information you need to fix your home.

  16. Radon investigation in Czechoslovakia

    International Nuclear Information System (INIS)

    Burian, I.

    1992-01-01

    After a short description of the history of radon measurements in mines, the results of bare track detector application in dwellings are commented on. Many related methods and problems are discussed. Most experiences are similar to the published ones, but details are specific for Central Europe (absence of air-conditioning, etc.). (author)

  17. Radon in dwellings

    International Nuclear Information System (INIS)

    1987-01-01

    This report gives a review of the present situation in Sweden concerning the knowledge and research on radon in dwellings.The responsibilities and need for actions in this field are examined. Costs and possibilities for financial help to install radonreducing equipment are also treated. (L.E.)

  18. Concentration variation of radon in the room

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  19. 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.

  20. 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).

  1. Construction materials and Radon

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  2. Design and construction of a system to determine Radon-222 through alpha spectroscopy; Diseno y construccion de un sistema para determinar Radon-222 mediante espectroscopia alfa

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio M, J. [Universidad Autonoma del Estado de Mexico. Facultad de Quimica. Toluca (Mexico)

    1991-12-31

    The purpose of this work consists in the design a radon-222 gas measurement system utilizing a surface barrier detector with the objective to obtain a more accurate measurement for this isotope through an alpha particle spectrum and so to address as to avoid the activity influence of the descendants of short half-life, which are too beta particles emitters, already other methods it must be correction series to obtain the real value of radon activity. Here are presented the general properties properties of radon, the experimental part description indicating the design to measure the radon-222 gas and its parts, as well as too the standard separation of radium-226 starting from carnotite mineral. Finally, it is presented the results obtained with a discussion about it. (Author) results obtained with a discussion about it. (Author)

  3. Design and construction of a system to determine Radon-222 through alpha spectroscopy; Diseno y construccion de un sistema para determinar Radon-222 mediante espectroscopia alfa

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio M, J [Universidad Autonoma del Estado de Mexico. Facultad de Quimica. Toluca (Mexico)

    1992-12-31

    The purpose of this work consists in the design a radon-222 gas measurement system utilizing a surface barrier detector with the objective to obtain a more accurate measurement for this isotope through an alpha particle spectrum and so to address as to avoid the activity influence of the descendants of short half-life, which are too beta particles emitters, already other methods it must be correction series to obtain the real value of radon activity. Here are presented the general properties properties of radon, the experimental part description indicating the design to measure the radon-222 gas and its parts, as well as too the standard separation of radium-226 starting from carnotite mineral. Finally, it is presented the results obtained with a discussion about it. (Author) results obtained with a discussion about it. (Author)

  4. Radon in Norwegian dwellings

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  5. Indoor radon and earthquake

    International Nuclear Information System (INIS)

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

    2004-01-01

    For the first time on the basis of the Spitak earthquake of December 1988 (Armenia, December 1988) experience it is found out that the earthquake causes intensive and prolonged radon splashes which, rapidly dispersing in the open space of close-to-earth atmosphere, are contrastingly displayed in covered premises (dwellings, schools, kindergartens) even if they are at considerable distance from the earthquake epicenter, and this multiplies the radiation influence on the population. The interval of splashes includes the period from the first fore-shock to the last after-shock, i.e. several months. The area affected by radiation is larger vs. Armenia's territory. The scale of this impact on population is 12 times higher than the number of people injured in Spitak, Leninakan and other settlements (toll of injured - 25 000 people, radiation-induced diseases in people - over 300 000). The influence of radiation directly correlates with the earthquake force. Such a conclusion is underpinned by indoor radon monitoring data for Yerevan since 1987 (120 km from epicenter) 5450 measurements and multivariate analysis with identification of cause-and-effect linkages between geo dynamics of indoor radon under stable and conditions of Earth crust, behavior of radon in different geological mediums during earthquakes, levels of room radon concentrations and effective equivalent dose of radiation impact of radiation dose on health and statistical data on public health provided by the Ministry of Health. The following hitherto unexplained facts can be considered as consequences of prolonged radiation influence on human organism: long-lasting state of apathy and indifference typical of the population of Armenia during the period of more than a year after the earthquake, prevalence of malignant cancer forms in disaster zones, dominating lung cancer and so on. All urban territories of seismically active regions are exposed to the threat of natural earthquake-provoked radiation influence

  6. 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

  7. Construction of radon/radon daughter calibraton chamber

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  8. Compact detector for radon and radon daughter products

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  9. Human perception of radon risk and radon mitigation: Some remarks

    International Nuclear Information System (INIS)

    Neznal, M.; Neznal, M.

    2008-01-01

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

  10. Radon and radiation biology of the lung

    International Nuclear Information System (INIS)

    Crameri, R.; Burkart, W.

    1989-01-01

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

  11. Legal issues in radon affairs

    International Nuclear Information System (INIS)

    Massuelle, M.H.

    1999-01-01

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

  12. Radon exposure and lung cancer

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  13. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  14. Radon activities in natural gases

    International Nuclear Information System (INIS)

    Sajo, B.L.; Palfalvi, J.

    1995-01-01

    Radon activities have been measured in gas samples used for residential heading, in Venezuela and in Hungary. Gas bottles were selected randomly in different regions, and radon activities were monitored with ionization clambers and solid stoke track detections. Radon concentrations in household natural gas are presented for regions in Venezuela and in Budapest, Hungary. The latter was found to be in the range of 88-135 Bq/m 3 . (R.P.)

  15. Radon exposures in the UK

    International Nuclear Information System (INIS)

    O'Riordan, M.C.

    1992-01-01

    Public and occupational health protection against radon is provided in the UK. Protection is advised where geological conditions cause high concentrations in domestic and commercial buildings. These circumstances are described and the resulting exposures reviewed. An account is given of the limitation scheme for radon in the home and the regulatory scheme for radon at work, the manner in which they are implemented, and the degree to which they are successful. (author)

  16. Measuring radon in the workplace

    International Nuclear Information System (INIS)

    Boyd, M.

    1990-01-01

    The Environmental Protection Agency (EPA) has issued guidance for testing for radon in homes and interim guidance for testing in schools. Information on testing for radon in the workplace is the next initiative and this paper describes the current status of this effort. The results of measurements made in several buildings in the Washington, DC area are discussed. In this paper a discussion of preliminary guidance on radon survey design that has been offered to Federal agencies is presented

  17. Radon Research Program, FY 1992

    International Nuclear Information System (INIS)

    1993-04-01

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

  18. 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....

  19. Radon Research Program, FY-1990

    International Nuclear Information System (INIS)

    1991-03-01

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

  20. Radon levels in Croatian spas

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  1. Radon studies in Indian dwellings

    International Nuclear Information System (INIS)

    Khan, A.J.

    2000-01-01

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

  2. [Mutagenicity of radon and radon daughters

    International Nuclear Information System (INIS)

    1990-01-01

    The current objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence will be studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions will be investigated by comparing the response of L5178Y strains which differ in their ability to rejoin X radiation-induced DNA double-strand breaks. This report discusses progress incurred from 4/1/1988--10/1/1990. 5 refs., 9 figs., 6 tabs

  3. 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

  4. A personal radon dosemeter

    International Nuclear Information System (INIS)

    Oberstedt, S.; Vanmarcke, H.

    1994-03-01

    In the last decade the radon issue has become one of the major problems of radiation protection. Animal studies as well as epidemiological studies showed an increased lung cancer risk. A new personal radon-dosemeter on the basis of a CR-39 (poly-allyl diglycol carbonate) track-etch detector has been developed. The read-out of the detectors is based on the image- processing technique. The actual efficiency of the new dosemeter, obtained with a semi-automatic personal-computer based image-analysis system, is 1.43 +/- 0.15 tracks/cm 2 /(kBq/m 3 h), which is about three times that of the widely used Karlsruhe-type detector based on polycarbonate detectors

  5. Radon measurements indoors

    International Nuclear Information System (INIS)

    Joensson, G.

    1983-02-01

    Measurements of Radon concentrations have been made using photographic film detectors in the communities of Uppsala, Soedertaelje and Tyresoe. The result from 6700 filmexposures in both one-family and apartment houses are reported. The fraction of dwellings with radon daughter concentrations exceeding 200 Bq/m 3 is between 3 and 14 percent for one-family houses and 0 to 5 percent for apartment buildings. 8 to 68 percent of the one-family houses and 57 to 83 percent of the apartment buildings had concentrations lower than 70 Bq/m 3 . The seasonal variations were recorded in one-family houses in Uppsala. In houses with low concentrations, the winter values were higher than the summer values. For houses with high concentrations the reversed variation was recorded. (Author)

  6. EPA's radon study results

    International Nuclear Information System (INIS)

    Dowd, R.M.

    1988-01-01

    Last winter, in cooperation with agencies in 10 states and two metropolitan area counties, EPA measured the indoor air radon concentrations of 14,000 houses, some chosen statistically at random and some by request of the homeowner. Passive measurement methodologies were used, such as exposing a charcoal canister to the air for a few days and allowing the air to migrate in to the charcoal naturally. To reduce dilution of radon by the outside air, the protocol required that the house be shut up; therefore, the study was conducted during winter. The measuring device was placed in the lowest livable area (usually the basement) of each house to maximize potential concentration. It should be noted that these procedures are generally considered to be screening tests because they result in a worst-case measurement rather than a best value. The results of these findings are presented

  7. Indoor radon II

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Because of the growing interest in and public concern about indoor radon, APCA, in April 1987, sponsored the Second International Specialty Conference on Indoor Radon. This book is the proceedings of this conference and includes discussions on: A current assessment of the nature of the problem; Issues related to health effects and risk assessment; The development of public and private sector initiatives; Research into methods of control and prevention; International perspectives; and Measurement methods and programs. The material is intended for the technically oriented and for those responsible for developing programs and initiatives to address this important public health issue. Contributors include federal, state, and provincial program officials and members of the academic and private sectors

  8. Indoor air radon

    International Nuclear Information System (INIS)

    Cothern, C.R.

    1990-01-01

    This review concerns primarily the health effects that result from indoor air exposure to radon gas and its progeny. Radon enters homes mainly from the soil through cracks in the foundation and other holes to the geologic deposits beneath these structures. Once inside the home the gas decays (half-life 3.8 d) and the ionized atoms adsorb to dust particles and are inhaled. These particles lodge in the lung and can cause lung cancer. The introduction to this review gives some background properties of radon and its progeny that are important to understanding this public health problem as well as a discussion of the units used to describe its concentrations. The data describing the health effects of inhaled radon and its progeny come both from epidemiological and animal studies. The estimates of risk from these two data bases are consistent within a factor of two. The epidemiological studies are primarily for hard rock miners, although some data exist for environmental exposures. The most complete studies are those of the US, Canadian, and Czechoslovakian uranium miners. Although all studies have some deficiencies, those of major importance include uranium miners in Saskatchewan, Canada, Swedish iron miners, and Newfoundland fluorspar miners. These six studies provide varying degrees of detail in the form of dose-response curves. Other epidemiological studies that do not provide quantitative dose-response information, but are useful in describing the health effects, include coal, iron ore and tin miners in the UK, iron ore miners in the Grangesburg and Kiruna, Sweden, metal miners in the US, Navajo uranium miners in the US, Norwegian niobian and magnitite miners, South African gold and uranium miners, French uranium miners, zinc-lead miners in Sweden and a variety of small studies of environmental exposure. An analysis of the epidemiological studies reveals a variety of interpretation problem areas.172 references

  9. Radon - The management of the risk related to radon

    International Nuclear Information System (INIS)

    2010-01-01

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

  10. Radon diffusion through multilayer earthen covers: models and simulations

    International Nuclear Information System (INIS)

    Mayer, D.W.; Oster, C.A.; Nelson, R.W.; Gee, G.W.

    1981-09-01

    A capability to model and analyze the fundamental interactions that influence the diffusion of radon gas through uranium mill tailings and cover systems has been investigated. The purpose of this study is to develop the theoretical basis for modeling radon diffusion and to develop an understanding of the fundamental interactions that influence radon diffusion. This study develops the theoretical basis for modeling radon diffusion in one, two and three dimensions. The theory has been incorporated into three computer models that are used to analyze several tailings and cover configurations. This report contains a discussion of the theoretical basis for modeling radon diffusion, a discussion of the computer models used to analyze uranium mill tailings and multilayered cover systems, and presents the results that have been obtained. The study has been conducted using a four-phase approach. The first phase develops the solution to the steady-state radon-diffusion equation in one-dimensieered barriers; disposal charge analysis; analysis of spent fuel policy implementation; spent f water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Uranium concentrations in the sediments which were above detection limits ranged from 0.10 t 51.2 ppM. The mean of the logarithms of the uranium concentrations was 0.53. A group of high uranium concentrations occurs near the junctions of quadrangles AB, AC, BB, a 200 mK. In case 2), x-ray studies of isotopic phase separation in 3 He-- 4 He bcc solids were carried out by B. A. Fraass

  11. A nationwide radon concentration survey project in Japan. Outdoor and workplaces

    International Nuclear Information System (INIS)

    Oikawa, S.; Kanno, N.; Ohashi, N.; Abukawa, J.

    2003-01-01

    Nationwide survey for outdoor and workplace radon ( 222 Rn) concentration in Japan were carried out to evaluate the effective dose to the general public due to 222 Rn and its progeny. The 222 Rn concentration was measured by using passive-type radon/thoron discriminative monitor equipped with polycarbonate films. Concentration of 222 Rn was calculated from etch pit counts appeared on the polycarbonate film after chemical and electrochemical etching. For outdoor 222 Rn survey, the monitors were installed at about 700 points throughout Japan on every quarters of the fiscal year 1997 to 1999. The mean concentration of outdoor 222 Rn concentration was 6.1 Bq m -3 from the results of 696 measurement points. Seasonal variation of outdoor 222 Rn was found to be minimal in July to September, and maximal in October to December. For workplace 222 Rn survey, the monitors were installed at about 700 points in four categories (office, factory, school and hospital) on every quarters of the fiscal year 2000 to 2002. Nationwide mean 222 Rn concentration in workplaces was found to be 22.7 Bq m -3 for 2000 and 20.7 Bq m -3 for 2001, respectively. Seasonal variation of 222 Rn concentration measured at office, factory, school and hospital were also found to be minimal in July to September, and maximal in October to December. (author)

  12. Indoor radon epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  14. Specific characteristics of radon passive/open model detectors compared to passive/close and charcoal devices

    International Nuclear Information System (INIS)

    Andru, J.

    1990-01-01

    All passive/open detectors, also called Unfiltered alpha Track Detectors (UTDs), are built around KODAK LR115 film, only material sensitive to all ambient alpha particles and capable to work in open mode. The principle of open detectors is not new. They are largely used worldwide, often by scientists (in France, Italy, Japan, Norway, Sweden etc.). However, their particular functioning needs some explanation and some reminders. This paper is more aimed to discuss generalities than details of calculation. The estimation of the Potential Alpha Energy (PAE) concentration is about 4 times better than that from other passive detectors and it includes thoron progeny. The film is more sensitive to ambient decay products than it is to Radon as track count is higher for alpha's of greater initial energy

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

    International Nuclear Information System (INIS)

    Stringer, C.W.

    1974-01-01

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

  16. Radon in waters from health resorts of the Sudety Mountains (SW Poland)

    International Nuclear Information System (INIS)

    Ciezkowski, W.; Przylibski, T.A.

    1997-01-01

    This paper discusses the geological background related to the presence of selected radon waters in the Sudety Mountains. Special attention is paid to radon waters whose chemical composition is formed within metamorphic rocks (mainly gneisses). The physical, chemical, and isotopic characteristics of the waters of Ladek Zdroj, Czerniawa Zdroj and Swieradow Zdroj are presented. The rocks at these locations are briefly characterized by their U, Th, and Ra contents. It was found that the basic role in enrichment of these waters with radon is played by the 100 m deep near-surface zone. This is related to the increased emanation coefficient in this zone as a consequence of weathering processes. It is also shown that the residence time of water in the rocks is not important for radon genesis. (author)

  17. Design and construction of a system to determine Radon-222 through alpha spectroscopy

    International Nuclear Information System (INIS)

    Bonifacio M, J.

    1991-01-01

    The purpose of this work consists in the design a radon-222 gas measurement system utilizing a surface barrier detector with the objective to obtain a more accurate measurement for this isotope through an alpha particle spectrum and so to address as to avoid the activity influence of the descendants of short half-life, which are too beta particles emitters, already other methods it must be correction series to obtain the real value of radon activity. Here are presented the general properties properties of radon, the experimental part description indicating the design to measure the radon-222 gas and its parts, as well as too the standard separation of radium-226 starting from carnotite mineral. Finally, it is presented the results obtained with a discussion about it. (Author) results obtained with a discussion about it. (Author)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  19. Radon Mapping of the Osijek Town

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  20. Indoor radon concentration in Poland

    International Nuclear Information System (INIS)

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

    1996-01-01

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