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Copyright of Journal of Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Long-term accumulation of coal gangue hill has a high risk of spontaneous combustion, and the toxic and harmful gases emitted by spontaneous combustion seriously pollute the atmosphere. The key to managing the spontaneous combustion fire of coal gangue hill lies in the accurate measurement of fire source location. However, measuring the fire source location of surface coal gangue hill lacks experimental and empirical research. In this paper, an oxidation warming experiment was conducted on the coal gangue samples, and the law of radon gas exhalation from coal gangue under different temperatures was analyzed. At the same time, surface thermometry and isotope radon measurement were applied to measure the high-temperature areas inside the gangue hill, and the measurement results were compared. The experimental results show that as the temperature of gangue increases, the amount of radon gas exhalation in gangue shows a changing trend of rising first and then decreasing. The radon exhalation from coal gangue can be divided into three stages. In the I stage (30 ~ 100°C), the evaporation of pore water in coal gangue leads to the exhalation of radon in water, causing the increase of radon concentration; in the II stage (100 ~ 350°C), the coal gangue is pyrolyzed at high temperature, and a large amount of radon is exhalated from the closed pores; in the III stage (350 ~ 450°C), after the first two stages of radon release, the number of radon atoms in this stage decreases, leading to a rapid decrease of radon concentration. The field measurement results show that compared with the surface thermometry method, the isotope radon measurement method is less disturbed by external conditions, and the circled fire area is more accurate, which has essential theoretical significance and practical application value for the accurate measurement of fire source location in coal gangue hill. [ABSTRACT FROM AUTHOR]

It is difficult to explore ground fissures in plain areas because of their hidden characteristics. Comprehensive geophysical exploration with its advantages of convenience and economic efficiency can quickly identify the spatial distribution, scale, and characteristics of ground fissures, and directly produce exploration results. Radon measurement method can detect the location of ground fissure, while high-density resistivity method can display the spatial characteristics of ground fissures. Combination of the above two methods can mutually complement and verify each other and obtain improved interpretation of the results. In this study, four comprehensive geophysical profiles were laid out near Gouquzhuang Village and Dapang Village for the Songzhuang ground fissures in Tongzhou, covering 330 high-density resistivity measurement points and 163 radon measurement points. The study found that the typical response of high-density resistivity measurement to ground fissures is resistivity isopleth abnormal changes, and develops low resistance zones when resistivity of the surrounding rock is relatively high. The response of radon measurement is anomalous peak values, most of which are saddle-like. Based on the measurement results, 10 ground fissures have been inferred, and their corresponding geophysical characteristics of the ground fissures summarized. [ABSTRACT FROM AUTHOR]

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Xietongmen County is located in the alpine mountain area of the Qinghai-Tibet Plateau, where the Kaga hot spring occurs. Geothermal energy is expected to be developed to solve the local heating problem, but research on the genesis and reserves of geothermal energy has not been carried out. By analyzing the geological structure and geothermal activity law of the survey area, and carrying out detailed geological survey, audio frequency magnetotelluric sounding and soil radon measurement near the Kaga hot spring, this paper discusses the genesis and thermal reservoir characteristics of ths Kaga hot spring by comprehensively using geological and geophysical exploration data. The research results show that (1) the audio frequency magnetotelluric and soil radon measurement results clearly reveal the extension and superposition relationship of the deep NE, NW and SN trending faults in the area, indicating that the area has a good permeable channel and thermal storage space. (2) The heat source in the study area is composed of the middle and shallow Eocene Oligocene magmatic rock decay exothermic heat source and the deep high-temperature magmatic melting heat source. The fracture zone is not only a deep thermal reservoir, but also a channel for the upwelling of deep hot water. The alluvial proluvial and other accumulative layers in the upper part of the Quaternary system are good caprocks of geothermal water, while the unconsolidated sediments in the lower part of the Quaternary system and some bedrock weathering crusts constitute shallow geothermal reservoirs in the area. These indicate that the geothermal application potential in this area is large, but it should be noted that, according to the three-dimensional display of audio frequency magnetotelluric sounding results, it is found that the deep S1 and S2 abnormal areas are connected at the shallow part, and the surface hot spring vent is just above its connecting channel, so the impact of the water volume of this hot spring vent needs to be evaluated when drilling water nearby. Finally, combined with the geothermal characteristics and electrical characteristics of geothermal water in this area, the “geophysical geothermal geology” model of the survey area is constructed, providing reference and guidance for the exploration and development of geothermal resources in other regions of Tibet.

Radon (Rn) is a naturally occurring radioactive inert gas in nature, and 222Rn has been routinely used as a powerful tracer in various aquatic environmental research on timescales of hours to days, such as submarine groundwater discharge. Here we developed a new approach to measure 222Rn in discrete water samples with a wide range of 222Rn concentrations using a Pulsed Ionization Chamber (PIC) Radon Detector. The sensitivity of the new PIC system is evaluated at 6.06 counts per minute for 1 Bq/L when a 500 mL water sample volume is used. A robust logarithmic correlation between sample volumes, ranging from 250 mL to 5 000 mL, and system sensitivity obtained in this study strongly suggests that this approach is suitable for measuring radon concentration levels in various natural waters. Compared to the currently available methods for measuring radon in grab samples, the PIC system is cheaper, easier to operate and does not require extra accessories (e.g., drying tubes etc.) to maintain stable measurements throughout the counting procedure. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Radon, prevalent in underground spaces, requires continuous monitoring due to health risks. Traditional detectors are often expensive, bulky, and ill-suited for humid environments in underground spaces. This study presents a compact, cost-effective radon detector designed for long-term, online monitoring. It uses a small ionization chamber with natural airflow, avoiding the need for fans or pumps, and includes noise filtering and humidity mitigation. Featuring multi-point networking and easy integration capabilities, this detector significantly enhances radon monitoring in challenging, underground conditions. • The structure and characteristics of a small cylindrical ion-pulsed ionization chamber are described. • The detector has mechanical noise filtering, and some measures have been taken to reduce the effect of air humidity. • The design feasibility is discussed from the perspectives of theory, simulation and physical objects. [ABSTRACT FROM AUTHOR]

A method for measuring radon-222 in drinking water by liquid scintillation counting has been validated according to the ISO/IEC 17025 criteria. A two-phase counting method based on ISO 13164-4 was selected. The counting parameter settings were studied for two water-immiscible cocktails, namely Mineral Oil Scintillator and Opti-Fluor O. Validation of the method includes repeatability, accuracy, uncertainty and detection limit. In order to ensure the validity of the results, internal quality controls should be used and trends analysed. These include background and efficiency control, and precision and accuracy determination. Furthermore, regular participation in interlaboratory comparisons or proficiency-testing programmes are essential. [ABSTRACT FROM AUTHOR]

Underground water is one of the main sources of radon for households. This article focuses on the estimation and removal of radon from underground water using the technology and inorganic sorbents developed by EKSORB Ltd., Russia for liquid radioactive waste treatment in the nuclear power industry. The article presents the results of tests of a system for the removal of radon and radon daughters from water patented by EKSORB. This is achieved by filtering water through RATZIR sorbent, followed by periodic load regeneration. Over a period of three years, the plant is successful in removing radon from the water that had an initial radon content of approximately 1500 Bq/L to less than 60 Bq/L, without releasing radon to indoor/outdoor air.

In this study, radon concentration measurements and chemical analyses of groundwater samples were performed in four sampling locations of Bartın Province of Western Black Sea Region, Turkey. 222Rn analysis was carried out in groundwater samples with liquid scintillation counting system in accordance with ASTM D5072 standard. The pH, total hardness, alkalinity and dissolved oxygen parameters of the groundwater samples were also determined. The radon concentrations for the water samples ranged between <3.00 Bq/L–12.03 Bq/L. Thirty eight percentage of the samples slightly exceeded the permissible limit of 11.1 Bq/L specified by USEPA for drinking waters. The annual effective doses of groundwater samples were calculated in the range of 7.41–30.74 μSv/y for ingestion of water (Ew.Ig), and in the range of 7.31–30.31 μSv/y for inhalation of radon released from water (Ew.Ih). The total calculated annual effective doses due to ingestion and inhalation were found to be below the limit value of 100 μSv/y specified by the World Health Organization (WHO). The radioactivity measurement results significantly varied for three sampling points but not for one sampling point on two different measurement dates, which is attributed to the differences in geological structure. The chemical analysis results, except for total hardness in two sampling points, were within the permissible limits specified by international standards. [ABSTRACT FROM AUTHOR]

Radon-222 (222Rn) is increasingly being used to measure and map groundwater-surface water interactions in natural waters. However, the direct measurement, without prior enrichment of 222Rn, allowing for a lower limit of detection of 0.2 BqL−1 is not sensitive enough to study 222Rn concentrations in the water close to or below 0.2 BqL−1. 222Rn enrichment prior to measurement, to increase the number of measured 222Rn decays, enables for improved measurement sensitivity. Here we show the influence of every parameter of 222Rn measurement and enrichment to enable optimisation of the 222Rn measurement. [ABSTRACT FROM AUTHOR]

In China, small coal mines refer to non-state-run coal mines with an annual production of less than 300,000 tons. The mining recovery rate of these small Chinese coal mines is low, and large amounts of coal remain in the gob. The mining seams of small coal mines are shallow, which induces extensive fissures between the gob and ground and provides easy pathways for air leakage. Consequently, long-term air leakage and oxygen supplies can result in spontaneous coal combustion in the gob, forming fire areas for many years. Determination of spontaneous combustion areas in the gob of small coal mines is difficult because fire sources are hidden underground and the geological data and roadway layout are poorly documented. Surface-based radon detection provides a fast, accurate, and low-cost method to identify spontaneous combustion areas in the gob of small coal mines. This study focuses on a small abandoned coal mine in Shanxi Province, China, using surface-based radon detection. Three abnormal temperature areas (A, B, C) and a potential abnormal temperature area (D) were identified. Drilling was subsequently performed to measure the temperature distribution in these areas. The results show that spontaneous combustion areas in small abandoned coal mine gobs can be successfully identified. [ABSTRACT FROM AUTHOR]

Copyright of Al-Mustansiriyah Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, indoor (air) and tap water Radon ( 222 Rn) measurements were performed at various campus areas of Giresun University. The measurement and analysis results were compared with the values recommended by international and national organizations and those reported in literature studies. The measured and calculated values were found to be under the recommended limits. Also, annual effective dose values were evaluated to determine the annual radon exposure of an individual working in the measurement area. Indoor radon concentration values measured by CR-39 detectors were in the range of 76 Bq/m 3 –504 Bq/m 3 and the mean concentration value was obtained as 193.7 Bq/m 3 . The radon concentrations in tap water samples were found to be in the range of 0.98 Bq/L–27.28 Bq/L. The annual mean effective doses ( E Wig ) of drinking water samples were calculated in the range of 9.9–150.4 (μSv/y) for ingestion and 0.97–14.84 (μSv/y) for inhalation calculations. Excess life time cancer risk (ELCR ) was estimated as 0.54%. Radon dose rate in terms of mean annual working level month was calculated as 0.246 WLM/year. The study was performed with a view to contribute to further studies in the related field and constitute a basis for the measurements conducted in this area. [ABSTRACT FROM AUTHOR]

In order to ensure good living standards, all risk factors are considered in ensuring work and life conditions. The urban lives we live can be influenced by the quality of air both at work and at home. Amongst environmental factors, air is essential to a good quality of life. A component that demands close supervision is the radioactive gas Radon. It originates both from natural radioactive constituents of Earth's crust and construction materials. This introduces variety to the places where Radon is found, both in terms of local geological structure as well as building characteristics. Radon concentration levels in inhabited buildings can also be influenced by the tenant's daily habits. Both the presence and measures of reducing the concentration of this radioactive gas require its monitoring. The adoption of EU directive 2013/59/Euratom draw attention on protection of the population and working personnel at Radon exposure, in buildings with public access and workplaces, from any source of Radon infiltration, whether originating from the ground and/or from construction materials. The Radioecology Laboratory INCDM "Grigore Antipa" - Constanta initiated a program of methodological testing and annual Radon monitoring. Preliminary results of Radon concentration measurements through an active method range from 10-429 Bq/m3 (Fig. 1). Constant supervision is maintained in order to consolidate observations of Rn concentration variation over time, as a function of meteorological parameters, this potentially serving as a benchmark for measurements in coastal areas. [ABSTRACT FROM AUTHOR]

In the present paper, a novel passive-type radon measurement technique based on Gafchromic XRQA2 film was developed. A Gafchromic XRQA2 film was modified by peeling off a polyester layer to enhance the film sensitivity to alpha particles, which were mainly emitted from radon and its progeny, and the response of the modified Gafchromic XRQA2 film to alpha particles was investigated. The results indicated that, with the increase in time-integrated alpha activity, the darkness of the exposed modified Gafchromic film increased, and only a small alpha energy dependence with less than 2% relative difference in the film response was observed. Next, the modified Gafchromic XRQA2 film was deployed with a RADUET container for radon measurement to evaluate application feasibility, and the radon response of the modified Gafchromic XRQA2 film was compared with the traditional one of a RADUET with CR-39 detector. The radon calibration was investigated using the radon exposure chamber. The obtained calibration functions showed that the net optical density of modified Gafchromic XRQA2 film was directly proportional to the accumulated radon concentration over the exposure period. From the calibration, the minimum and maximum detectable radon concentrations for a three-month measurement period were estimated to be about 390 Bq m−3 and 15,000 Bq m−3, respectively. Moreover, this technique enables to minimize the effect of thoron interference by the RADUET container design. These results suggest that this technique can be used for measuring radon, particularly in areas with potentially high radon concentrations, for example, underground mines and caves. • A novel passive-type radon measurement technique based on Gafchromic XRQA2 film was developed. • Gafchromic XRQA2 film was modified by peeling off a polyester layer to enhance the film sensitivity to alpha particles. • The modified Gafchromic XRQA2 film was deployed with a RADUET container for radon measurement. • This technique can be used for measurement radon with high concentrations. [ABSTRACT FROM AUTHOR]

In this paper, a comprehensive overview on the achievements and generated research results beyond the state-of-the-art is given based on the working structure of the joint metrology research project MetroRADON. The results of the project have been targeted at the implementation of the European Council Directive 2013/59/EURATOM on radiation protection (EU BSS) and benefit European and international standards on radon monitoring, radon measurement and calibration, geographical radon mapping, and guidelines on radiological protection, construction products, radiation instrumentation and nuclear data. • Traceable calibration of radon (222Rn) instruments at low activity concentrations. • Reducing the influence of thoron, temperature, and humidity on radon measurements. • Comprehensive study on existing radon measurement procedures in Europe. • "Geogenic Radon Hazard Index" (GRHI) - development of a new tool for radon mapping. • Calibration and measurement procedures for radon concentration in air. [ABSTRACT FROM AUTHOR]

The present paper describes the prototype of a calibration standard system for radon concentrations to be used in establishing the traceability of radon concentration measurements in dwellings. Radon gas was generated with a radium-226 solid source in a certified volume as a closed system. The activity of the radon that was released in the closed system was determined from the difference between the absolute activity of the standard radium solid source and the residual radon decay products ( 214 Bi or 214 Pb). A high-purity germanium (HPGe) detector, which was calibrated using gamma reference standard sources, was used to measure the activity of a radium solid source and radon decay products ( 214 Bi or 214 Pb). The emanation factor of the 226 Ra source was controlled online with the HPGe detector. Radon activity was achieved at ~1500±45 Bq from the radium source at 3.95±0.2 kBq under equilibrium conditions. After this activity, the radon gas was transferred into the closed system producing radon activity concentrations of 31.1±0.3 kBq/m 3 . Systematic errors were found of less than 4% with a random error around 0.5%. The random error is generally associated with the estimation of the count rate of the measured radon progenies ( 214 Po and 214 Po for alpha measurements or 214 Pb and 214 Bi for gamma measurements), but systematic errors are associated with the errors introduced by the instrumentation and measurement technique. The system that was developed has a high degree of accuracy and can be recommended as a national or regional prototype standard of radon activity concentration to calibrate different working radon measurement devices. [ABSTRACT FROM AUTHOR]

CR-39 is a solid nuclear track detector that is commonly used for long-term passive radon monitoring. For a specific incident particle, etching condition and type of CR-39, the morphology of the nuclear tracks in CR-39 varies with the energy and angle of incident particles. This study systematically compares the performance of six different passive radon monitors from the perspective of nuclear track morphology using both theoretical calculations and experiments. Based on different shapes of exposure chambers for these monitors, different strategies for dealing with incident α particles can be observed, especially for those emitted from deposited progeny on the inner wall. These characteristics contribute to the strengths and weaknesses of each monitor in terms of efficiency, uncertainty, robustness in measurement, and consistency of track morphology. The results of this study revealed that the optimisation of the radon monitor should be multidirectional and situation-oriented. It was expected to be helpful to improve radon measurement using these monitors. • Comparison of track morphological characteristics among passive radon monitors is conducted theoretically and experimentally. • Shape of the diffusion chamber influences monitor efficiency and the morphological characteristics of the tracks. • The selection and design of radon monitors should be multi-directional and situation-oriented. [ABSTRACT FROM AUTHOR]

Radon concentration and annual effective doses were measured in drinking water in the Southern Part of West Bank – Palestine, by using both passive and active techniques. 184 samples were collected from various sources i.e. tap water, groundwater, rain waters and mineral waters. It is found that the annual effective dose resulting from inhalation and ingestion of radon emanated from all types of drinking water is negligible compared to the total annual effective dose from indoor radon in the region. Results reveal that there is no significant public health risk from radon ingested and inhalation with drinking water in the study region. [ABSTRACT FROM AUTHOR]

The purpose of this study is to characterize in detail the temporal changes in Rn (radon-222) concentration in soil gases near fumaroles and clarify its correlation with volcanic earthquakes and temperatures in two geothermal reservoirs. Mt. Aso crater in southwest Japan, which has two reservoirs on its western side estimated by magnetotelluric survey to be at about 2km in depth, was selected for this study. For the long-term survey, the α scintillation counter method was used weekly for 12.5years at the three hot springs within a 2-km range. Rn concentrations were calculated using the CRAS method, a calculation method that considers radioactive equilibrium or nonequilibrium state of the soil gas. Rn concentrations generally showed similar fluctuation patterns among the sites. CRAS was used as a new indicator for evaluating the age of the soil gas. This age corresponds to the elapsed time determined from the generation of Rn based on the measurement of the numbers of atoms of Rn and its daughter 218Po at the start of measurement. In comparing the Rn data with the history of earthquakes in the Aso caldera, volcanic seismicity was identified as a major controlling factor in the sudden increase and decrease in Rn concentration as a function of age. For more precise detections of change, Rn concentrations were measured continuously at one site by pumping soil gas from a borehole and using an ionization chamber over 2.5years. Five chemical components (He, H2, N2, CH4, and CO2) were then measured by gas chromatography at 1-week intervals. Because Rn concentrations are affected strongly by atmospheric temperatures, the residual components were obtained by subtracting the trend of the components from the original data. Chemical component data were used to estimate the temperature and pressure in the reservoir at the site; temperatures ranged from 229 to 280°C, (average 265°C, average pressure 80MPa). Residual Rn concentrations showed a clear correlation with temporal changes in estimated temperature and, to a degree, with pressure. Considering the migration mechanism of Rn by molecular diffusion and advection under rapid gas upflow conditions, change in the diffusion coefficient is regarded as a possible factor to have induced temporal changes in Rn concentrations in conjunction with the temperature changes in the reservoirs. In addition, the increase of the amount of degassed Rn from the advective–convective hydrothermal fluids, which is associated with wall-rock fracturing, is another important factor. Earthquakes likely enhance the permeability of a reservoir by generating fractures, which in turn can cause an increase in the reservoir temperature, upflow fluid velocity, and gas flux. This provides one possible interpretation for the significant correlation of Rn concentrations with earthquakes. [ABSTRACT FROM AUTHOR]

Radon gas concentrations in ferruginous, quartzitic/conglomeratic and carbonatic caves were measured and the results obtained in each lithology were compared. Three representatives of each formation (nine caves in total) were studied. The caves are located in three environmental preserved areas in the Ferriferous-Aquifer Quadrangle and in its regional surrounding, in the center-south portion of Minas Gerais State, Brazil. It was found that the average concentration in quartzitic/conglomeratic caves (4,759 Bq/m3) was much higher than those obtained in carbonatic (844 Bq/m3) and ferruginous (945 Bq/m3) caves. This result most likely reflects differences in the uranium content of the rock types. Also, for a better understanding of the radon distribution inside the caves, concentration maps with their interpolated values were generated using geospatial analysis tools. • For the first time, radon (222Rn) gas was measured in non-carbonatic caves. • The quartzitic caves had the highest average 222Rn concentration (4.8 kBq/m3). • Ferruginous and carbonatic caves had average values of 945 and 884 Bq/m3, respectively. • 222Rn levels correlated to uranium concentration in the studied lithologies. [ABSTRACT FROM AUTHOR]

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

A simple and easy to use radon calibration chamber of volume of 216 litres was designed and constructed for applications in calibration of radon measuring devices and for research studies. The main advantage of this chamber is that instead of using

Abstract: The behavior of alpha silicon diodes, gamma crystal scintillators and ionization chamber detectors employed for long-term radon monitoring in geological media was studied and a comparison of the efficiency and sensitivity, the capability to resolve signal to noise, background, stability, and reliability of their long-term measurements is presented. An understanding of the qualities of monitoring techniques is necessary for determining suitability to the characteristics of the individual monitoring site and what exactly they will measure: radon in an air cavity, in porous media or in water. The experimental layout was located inside the Amram Mountain research tunnel near Elat (Gulf of Aqaba), within a closed room in the tunnel core. This enabled monitoring natural temporal radon variations under fairly stable internal conditions, at a high-resolution sampling rate of once every several minutes. In an interval of several days, all the sensors responded simultaneously to the same eventual radon variations. An ionization chamber device, the AlphaGUARD designed with a long-time stable calibration factor and an inherent QA-System, was used as reference calibration of the different radon detectors. The results indicate that the higher sensitivity of 2–4 orders of magnitude exhibited by gamma sensors even with narrow dimensions (1" × 3" BGO detector) are preferred for long-term radon monitoring in comparison to the solid-state alpha detectors and ionization chambers. [Copyright &y& Elsevier]

Abstract: Over the past 15 years scientific research and application-oriented research were carried out in Austria to resolve the radon problem. In this paper, the strategy and progression of radon research in Austria and experience gained by practical implementation of the main findings are shown and discussed comprehensively. The overview includes the results of the national radon survey, radon mitigation and precaution studies, indoor-air studies at kindergartens and schools, soil–gas radon research, and the establishment of national radon precaution and mitigation standards. [Copyright &y& Elsevier]

In order to maintain an acceptable Indoor Air Quality (IAQ), policies, strategies and guidelines have been developed worldwide and exposure concentrations of the indoor radon have been specified. Mapping indoor radon levels for a region could be done with intensive measurements on a large number of samples. To obtain the most accurate estimate of the levels with the uncertainties specified, a statistical model has been developed in this study to predict the fractions of samples in a region having an average radon level above the action levels of 150Bqm−3 and 200Bqm−3. The model was based on a transformation of the variation from a small sample set of data to a population geometric distribution via an estimator, known as the ‘sample correction factor’. Using a dataset from a cross-sectional measurement of indoor radon levels in 216 Hong Kong offices, where the mean was 37.2Bqm−3 and the 68% range was from 17.3Bqm−3 to 80.3Bqm−3, the ‘sample correction factor’ was evaluated and tested by the Monte-Carlo simulations. The model estimates of the fractions above the indoor radon action levels 150Bqm−3 and 200Bqm−3 (1.2–7.7% and 0.4–4.1% for a sample size of 20, 2.8–5.1% and 0.8–2.4% for a sample size of 60) were demonstrated to be consistent with those determined from the dataset (3.5% and 1.4%). With the ‘sample correction factor’ thus quantified, it will be possible to provide the required data for the policymakers making appropriate decisions on resources and manpower management. [Copyright &y& Elsevier]

Abstract: We have developed a simple and portable technique for measuring moderately high levels of 222Rn (t 1/2 =3.8d) in natural waters such as coastal water, groundwater, and river water. The water sample is carefully collected in a glass bottle, and the sample bottle is connected to a radon-in-air monitor in a closed air-loop mode. By purging air through the sample, radon is emanated from the water until a chemical equilibration is obtained between the two phases. The radon in the air loop is determined using the radon-in-air monitor. Then, the radon in water is calculated by a radon-partitioning factor between water and air for a measured water temperature. This technique is especially convenient for determination of 222Rn in natural waters on field sites, since it eliminates the preparation of He gas, cold traps, and alpha-scintillation cells and counter, which are required for traditional radon emanation methods. [Copyright &y& Elsevier]

Abstract: In order to maintain an acceptable indoor air quality (IAQ), policies, strategies and guidelines on achieving the required IAQ have been developed worldwide. In Hong Kong, the Environmental Protection Department (HKEPD) has launched an IAQ certification scheme to promote an acceptable IAQ in workplaces. For the practical radon measurement, an 8-h continuous monitoring is proposed for the assessment purpose. However, the uncertainties and measurement efforts associated with the method have not been detailed. In this study, the probable errors and measurement efforts in measuring the indoor radon concentration by three proposed sampling schemes of various sampling periods have been investigated. Scheme A is to obtain an average concentration over a sampling period in an occupied period; Scheme B is to obtain an average concentration in two sampling periods from two sessions of the occupied period; and for Scheme C, the average concentration in two structural sampling periods from two sessions of the occupied period. In particular, a 1-year measurement of indoor radon concentration in a typical office building has been used as basis to evaluate the probable errors between the long-term average and those obtained by the three measurement schemes. At a certain confidence level, the results show that the measurement time required for Schemes B and C could be reduced significantly, when compared with Scheme A using continuous monitoring. It is recommended to specify the measurement uncertainty and effort in future codes, and the sampling schemes could be considered in determining the practical strategies for radon measurement. [Copyright &y& Elsevier]

In order to provide reference 222Rn activity concentration, a device based on the alpha spectrometric measurement of 218Po collected electrostatically on a PIPS detector, has been developed and characterised. Traceability is achieved by the use of primary 222Rn standard activity inside a glass bulb obtained from the Physikalisch–Technische Bundesanstalt. Radon standard activity is then transferred to the instrument that measures the reference radon activity concentration. The instrument is used in the walk-in radon chamber of the Institute of Energy Technology at the Technical University of Catalonia in order to provide a reference atmosphere for the calibration of radon concentration detectors. Under typical environmental calibration conditions within the radon chamber, an expanded uncertainty of roughly 4% (k=2) for radon concentration is usually estimated. [Copyright &y& Elsevier]

With the announcement of the Government of Canada’s Radon Guideline and increased public awareness of radon risk, more and more Canadians wish to test their homes for radon. Radon service providers available on the Internet have attracted many homeowners’ attention. These services provide an easy and less expensive way for homeowners to test radon levels in their homes. However, a question has frequently been asked, ‘How reliable are the radon testing services available on the Internet?’ To answer this question, we ordered 36 radon testing kits from 10 service providers on the Internet. The test results showed that online radon testing services could collectively meet the performance requirement. However, the quality of a few service providers needs to be improved. Practical Implications Indoor radon tests were performed with detectors ordered from 10 service providers available on the Internet. The results showed that online radon testing services could collectively meet the performance requirement. However, the quality of a few service providers needs to be improved. [ABSTRACT FROM AUTHOR]

In dwellings, the radon and their daughter products contribute the largest fraction to the doses received from natural background radiation. In the present study, the radon levels at Madurai district of Tamilnadu have been measured initially for 15 dwellings using cellulose nitrate (C6H8O9N2) LR-115 type II (non-pelliculable) films and the dose assessment due to radon and its daughter product concentrations is calculated. These results were intercompared with other terrains viz. Jodhpur district of Rajasthan which is considered as semi-desert terrain and Jammu district of Jammu & Kashmir which is the hilly area. Also the natural radioactivity in soil samples of Madurai have been measured using NaI(Tl) detector based gamma spectrometry. From these radioactivity levels, the radium equivalent activity is calculated and a correlation between this and radon concentration has been tried out. [Copyright &y& Elsevier]