Radon Emanation Research Articles

Exploring the potential use of silver-exchanged zeolites for adsorption of radon traces in low background experiments

Abstract Radon is an important source of radioactive background in experiments searching for rare decays and in the field of low-energy particle physics. Here, we report the first temperature-dependent study of radon adsorption on silver-exchanged zeolites from several commercial producers. Among the three tested zeolites, Ag-ETS-10 showed the best result. Hence, it was chosen for the further study of internal radioactivity and radon emanation, which are important characteristics of materials used in low-activity experiments. The important role of silver in radon adsorption is demonstrated by comparison of the silver-exchanged zeolites with their unexchanged counterparts. Furthermore, the temperature-dependent measurements showed that the enhancement of the radon adsorption upon the introduction of silver in zeolite occurs due to the increase of the heat of adsorption. This opens a new perspective for the search for highly efficient radon adsorbents.

Radioassay facilities at the STFC Boulby Underground Laboratory

For future low-background particle physics experiments, it will be essential to assay candidate detector materials using an array of assay techniques. To minimise the risk of sample contamination whilst moving between assay techniques, it is also sensible to minimise the distance between assay stations, particularly for non-destructive techniques where the sample may end up being installed into an experiment. The Boulby UnderGround Screening (BUGS) Facility comprises an array of germanium detectors, two XIA UltraLo-1800 surface-alpha counters, two radon emanation detectors and an Agilent ICP-MS system. This article describes each of these systems.

Annual effective dose estimation of radon in drinking water sources of Nizampur basin, North Western Pakistan

ABSTRACT This study assessed radon (222Rn) levels in drinking water sources in the Nizampur basin and their potential health risks for the local community. We analyzed 48 water samples on-site using RAD7. Additionally, we measured pH, temperature (T), total dissolved solids (TDS), redox potential (ORP), and electrical conductivity (EC) with a multiparameter analyzer. Results showed pH, T, TDS, ORP, and EC ranging from 7.2 to 8, 17 to 26 °C, 333 to 1130 mg/l, –56 to 284 mV, and 469 to 2370 µS/cm. 222Rn levels varied significantly (0.7–107 Bq/l, mean 23 ± 21, median = 17 Bq/l), with about 65 % exceeding the EPA's limit of 11.1 Bq/l, indicating health risks likely due to local geological conditions. The annual effective doses for ingestion (EwIng) were 0.87 ± 0.01, 0.35 ± 0.006, and 0.13 ± 0.002 µSv/a for adults, infants, and children, respectively. Exposure risk via the inhalation (EwInh) route ranged from 1.75 to 270 µSv/a, with the highest risk in infants, followed by children and adults. Inhalation was the primary exposure route for all age groups. Further, spatial distribution maps and hotspot analysis suggested that the central region characterized by high structural deformation and favorable geology for radon emanation was the area of concern in terms of health risks.

Assessment of natural radioactivity and radon release potential of silurian black shales

Many countries are developing a radon action plan to provide decision-makers with a reliable tool for reducing the harmful effects of radon exposure in dwellings and among the general public and, accordingly, to implement land development strategies. Mapping the geogenic radon release in different geological environments could assist in delineating areas that require priority monitoring and regulation, as well as applying radon reduction techniques in newly constructed buildings. In this paper, the activity concentration of 238U, 226Ra, 232Th and 40K and the exhalation rate of 222Rn have been estimated for the Silurian black shales of Villasalto, a district in the south-eastern Sardinia (Italy). The radioactivity of 226Ra, 232Th and 40K radionuclides was found relatively high (256.32 ± 87.00 Bq.kg−1), low (44.16 ± 9.47 Bq.kg−1) and moderate to high (856.28 ± 392.41 Bq.kg−1) respectively. The radon emanation coefficient (E) and the radon production rate (PRn) have been calculated based on the analysis of the radon growth model inside a sealed chamber. E was found to correlate well with the activity concentration of 226Ra, as well as with the grain size of the soil/rock samples under investigation. PRn was relatively high, ranging from 212.54 to 524.27 Bq.m−3.h−1. Furthermore, the mean value of the main radiation hazard indexes (i.e., the radium equivalent activity, the outdoor gamma-ray dose rate and the annual effective dose) were found to be 299.07 ± 138.62 Bq.kg−1, 169.97 ± 75.58 nGy h−1 and 0.21 ± 0.09 mSv.y−1 respectively.

Evaluation of potential radiological hazards of unfired construction materials containing fly ash in Vietnam.

In this study, the specific activities of 226Ra, 232Th and 40K in the unfired construction materials (solid card bricks, 4-hole bricks, pavement bricks) containing fly ashand bottom ash from a coal-fired thermal power plant in Vietnam were measured using the low-level gamma-ray spectrometer with HPGe detector. Also, the 222Rn concentrations in these materials were analyzed using RAD7 radon monitor and then radon mass exhalation rate and emanation fraction of these materials were calculated. The potential radiological hazards for residents living in the model room made of these materials were evaluated. The average specific activity of 226Ra, 232Th and 40K were found as 67.7, 79.3 and 703.5Bqkg-1, respectively. The total annual effective dose (due to external gamma exposure and internal radon exposure for resident living in the CEN model room made of the unfired brick samples) was found as 0.9mSvy-1 which is lower than the worldwide average dose of 2.4mSvy-1. Calculations from ResRad-Build code showed that the doses due to radon exposure account for from 62.3% (at the first year) to 98.8% (at the next 30years) of the total gamma and radon dose. Under low air exchange to the outside environment, from the 6th year onwards, the total dose may exceed the average dose value from natural radiation exposure sources.

Distribution of radioelements in rock-water-air systems from the Caldas Novas hydrothermal complex (GO), Brazil

Radioactivity measurements have been done in rocks and groundwater samples of Caldas Novas Hydrothermal Complex, Goiás State, Central Brazil, aiming to investigate if the rock matrices could be responsible for transferring high levels of radionuclides into the atmosphere and liquid phase. Gamma spectrometry showed that rocks presented low concentrations of uranium (eU = 226Ra), thorium (eTh = 228Th) and 40K as confirmed by laboratorial radon (222Rn) emanation experiments that yielded low values in both, liquid and gas phases. The monitored dissolved radionuclides in waters were 222Rn, 210Pb, 223Ra, 224Ra, 226Ra, 228Ra, 234U, and 238U, whose activity concentration was compared with the guideline reference values established by the World Health Organization (WHO) for drinking water. The results obtained for the committed effective dose (CED), based on a drinking water ingestion rate of 2 L/day throughout a year, did not surpass the WHO reference level of 100 μSv/year.

Applying machine learning to model radon using topsoil geochemistry

Radon is classified as a Class 1 carcinogen, being the leading cause of lung cancer in non-smokers. Understanding the prominent sources of radon helps to mitigate against the adverse effects of radon exposure. Considering soil-gas radon is the main contributor to indoor radon, it is possible that soil geochemistry can be used as a proxy for the soil radon emanation potential or geogenic radon classes for a particular location. This paper investigates the relationship between soil geochemistry and geogenic radon. A large area of 17,983 km2 from the West, Midlands and East of Ireland was selected to represent a range of geology types and radon categories. A rigorous assessment is presented to investigate the relationship of geogenic radon and topsoil geochemistry; using univariate processes (i.e. r2, Pearson r and heatmaps) and multivariate techniques (i.e. principle component analysis (PCA) and machine learning (ML) algorithms including Gaussian process regression, logistic regression and random forest). Here, PCA and ML techniques were used to test the utility of soil geochemistry to predict geogenic radon classes. Gaussian Process Regression yielded the highest accuracy (74%) and f1-score (0.74) of all models. The feature importance (i.e. highest ranking elements for predicting geogenic radon class) from the ML models outputs elements including [Y, Tl, Mn, Cr, Co, Be, Sc and Rb]. The PCA biplot demonstrates that these elements cluster in conjunction with higher geogenic radon categories. Multivariate data analysis reveals that certain elements important for predicting higher geogenic radon classes, also covary together within topsoil samples; here these are termed “radon-prone elements”. Spatial covariance of radon-prone elements permits soil geochemistry to be used as a tool for understanding the distribution of geogenic radon. The methodology presented in this paper provides a comprehensive geo-statistical approach to investigate the relation between topsoil geochemistry and geogenic radon. This approach could be applied as a diagnostic tool to assist radon mitigation measures, hence adding value to legacy soil geochemistry datasets.

Estimation of radon emanation power: a comparison of different methods

Estimation of radon emanation power: a comparison of different methods

Measurements of Radiometric Concentrations for <sup>222</sup>Ra, <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K in Soil Samples from Two Uranium Mines’ Stockpiles, Erongo Region, Namibia

<p>The continuous exposures from radiations to human population has led to research studies on evaluating the radioactivity concentrations in most parts of the world. Naturally occurring radioactive materials (NORM) have been greatly regarded as the chief sources of both terrestrial and cosmological radiations. In this study a high-purity germanium well detector was used to measure the activity concentrations of samples from mines 1 and 2 considered in the study. The measured average activity concentration for <sup>226</sup>Ra, <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K in mine 1 were estimated at 2546±10, 557±13, 215±2 and 1079±26 Bq.kg<sup>-1</sup>, respectively. For mine 2, the estimated average values of the radionuclides of <sup>226</sup>Ra, <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K were calculated as 4414±27, 842±29, 436±5 and 2225±52 Bq.kg<sup>-1</sup>, respectively. The high concentration of radium in samples contributed to high rate of radon emanation into the atmosphere, ground and surface water as well and, if no remedial measures are put in place, this may contribute to plants, animals and eventually human exposures in the region. The study concludes that mine tailings contribute to an increase in background radiation in the environment due to the fact that they are uncovered and deposited in the open environment, resulting in wind-blown <sup>226</sup>Ra carrying dust entering nearby residential dwellings. The exposures rates could also be increased by other possible transfer pathways, such as ingestions, inhalations and external gamma radiations. Mining companies are urged to decrease windblown atmospheric exposure by using water tanks mounted on mining equipment to sprinkle on top of the soil or covering the tailings with canvas sheet.</p>

Integration of Geophysical Methods to Study Deep Structure of the Angara Fault, the Largest in the Baikal Rift

Abstract —The Angara regional fault which is transversal to the Baikal basin totals about 150 km in length and ranks as a major strike-slip fault with the normal component in the seismically active rift zone. Given that its vicinities represent an area with high population density, the emphasis needs to be placed primarily on the study of its structural features. At this, the Angara fault has been poorly studied by geophysical methods. Results of the specialized mapping carried out in the 1990s revealed the block structure of the Angara fault zone, however without a reliable identification of the fault plane, which leaves its position still to be debatable. To establish the Angara fault plane and studying its deep structure, the integration of such geophysical methods as magnetotelluric (MT) sounding, radon emanation and fieldwalking magnetic surveys was required. Their application in the study of the deep structure of the southern parts of the Angara fault allowed revealing anomalies in all of the measured fields, accordingly. The anomaly-forming object, which the authors associate with the deep penetrated Angara fault plane, was expressed in the most distinct way by the magnetotelluric data (as a high-resistivity region (ER = 8500 Ohm∙m) relative to the host rock) and radon emanation survey (radon volumetric activity index RAI ≥ 20). The fact that the magnetic field received only minor distortions from the object may indicate either moderate magnetic characteristics of the latter or a significant occurrence depth. The identified anomaly-forming object localized within the crystalline basement tends to be more sharply expressed in the left bank of the Irkutsk Reservoir, while in the upper part of the cross-section it is overprinted by rocks of the sedimentary cover.

Estimated versus field measured soil gas radon concentration and soil gas permeability

Prediction of areas with elevated natural radiation is fundamental for the prevention of human exposure. Soil gas radon activity concentration and soil gas permeability are predictive parameters for the radon potential, which has great importance in areas where future urban development is planned. In this study, the soil gas radon equilibrium concentration (C∞) and soil gas permeability (K) were estimated through the application of theoretical and empirical models found in the literature. These models apply soil properties as input parameters. Using already existing soil parameters to predict the radon potential of an area would be useful in avoiding direct field measurements. Therefore, in this study, we examined whether the estimated soil gas radon activity concentration and soil gas permeability values match the values measured in the field. The soil gas radon activity concentration estimated by two theoretical models is about 50% of the measured value in the studied area. This underestimation can be attributed to the assumption that the radon activity concentration measured in the field depends only on soil parameters and the models do not take into account the underlying bedrock. Additionally, these models neglect the radon transport by advection and consider only the radon availability and migration in homogeneous media. Furthermore, they do not count certain characteristics of the soil that can be relevant, e.g. organic matter and clay content in the soil. To investigate more in detail such soil characteristics, seven samples located roughly along the slope, were selected to determine the soil chemical composition by ICP-MS. Evaluating the physical and chemical properties of the soil, it was found that the sampling sites with pH < 8 (low calcium content) the preferential adsorption was a dominant process. This causes radium enrichment in organic matter and clay, which directly influence the soil gas radon activity concentration. At pH > 8, radium is no longer preferentially adsorbed on organic matter but continues to be adsorbed on clays albeit this process is weak because radium competes with calcium cations. Also, there are other factors that may affect radon emanation in soil such as radium concentration and distribution, porosity and water content. In contrast, empirical model of soil gas permeability overestimates the measured value in the study area by an order of magnitude. A new model was made by modifying the previously proposed one, which can be used as a guide for the estimation of the median value of soil gas permeability in granitic areas, but not as an accurate predictor due to the lack of correlation between the estimated and measured values.

In-depth study of radon in water in a Greek village with enhanced radon concentrations

This study focused on the radon transfer from the water to the air and the subsequent impact of waterborne radon indoors, taking advantage of the enhanced and decreasing from year to year radon-in-water concentrations observed in the Arnea village in Northern Greece. Some other essential aspects and observations regarding radon-in-water were also discussed. Concerning radon transfer from water to the air, the transfer efficiencies for showering and the use of the bathroom tap were estimated by measuring the radon-in-water and the waterborne radon-in-air concentrations in sealed bathrooms of two apartments in Arnea. The transfer efficiency for the bathroom tap use ranged from 22 to 28.9% for water flow rates of 2.7–7 L min−1. For showering, the transfer efficiency ranged from 45 to 48.3% for water flow rates of 6 L min−1 and 8 L min−1, respectively. As for the impact of waterborne radon indoors, each year's two-week monitoring of radon-in-water and radon-in-air concentrations in a house in Arnea from 2018 to 2022 revealed rapid and sharp increases in the bathroom air related to waterborne radon. Following the results obtained in the house's bathroom in Arnea, showering is the most significant exposure of humans to waterborne radon due to the person's proximity to waterborne radon, the enclosed space, the high transfer efficiency of showering, and the significant amount of water consumed. Each year's two-week average indoor radon concentrations measured in the examined house in Arnea showed that waterborne radon's contribution is less important than the other parameters affecting indoor radon, such as ventilation rates and radon emanation from the soil beneath the house's structure. Time variation (2018–2022) of radon activity concentration measured in a borehole supplying Arnea with water showed a relatively low standard deviation (10.2%) at a coverage factor of k = 1. A disequilibrium was observed between radon and its progenies immediately after pumping water from a borehole. This disequilibrium was observed for 1.3 years and seems to be continuous. Regarding radon removal from water, the diffused bubble aeration System constructed in Arnea reduces the radon-in-water activity concentration by more than 90% when using an air-to-water ratio of 10:1 and a detention time of 60 min. The System does not affect the adjacent outer space radon-in-air concentrations.

On the Radon-Related Mechanism of the Seismo- and Volcanogenic Geomagnetic Anomalies: Experiments in Tlamacas Mountain (Volcano Popocatepetl Area) and Electrode Effect Model

The noise-like behavior of the geomagnetic anomalies observed in Tlamacas station (volcano Popocatepetl, Mexico), linked to the ionization produced by intensive radon release, are presented in the experimental part of this study. The magnetic field perturbations produced by charge spreading currents within the fair-weather electric field are considered in the theoretical model based on the electrode. The electric charges are generated by the air ionization due to radon emanation. The simulations demonstrated that the ionization of the air leads to magnetic field perturbations of about 0.001–0.1 nT in the ULF (ultra low frequency) range 10−3–10−1 Hz. Magnetic field perturbations can be higher when the radon emanation occurs in a region with terrain irregularities.

Radioactivity of metallurgical enterprises waste

Abstract. Problem. The problem of obtaining environmentally friendly materials is especially relevant when using the wastes that concentrate natural radionuclides (NRN) dangerous for public health. The concentrators of radionuclides include dump and granular blast-furnace slags. Goal. The purpose of the work is to determine the radionuclide composition of the fractions of dump and granular blast-furnace slags from Ukrainian enterprises, their compliance with the radiation safety standards of Ukraine and international radiological indicators, and to identify the factors that determine the level of natural radioactivity of the slags. Methodology. The specific activity of natural slag radionuclides was determined by the gamma spectrometric method on a SEG-001 scintillation gamma spectrometer. The mineral composition of the crystalline component of the slag was determined using X-ray phase analysis performed on a Siemens D500 powder diffractometer. The elemental composition of blast furnace slag was determined by the method of electron-probe microanalysis on a JSM-6390 LV scanning electron microscope with an INCA micro-X-ray analysis system. The particle charge and electrokinetic potential were determined during macroelectrophoresis of suspensions. Results. The blast-furnace slag contains natural radionuclides: 226Ra, 232Th and 40K. The content of radionuclides varies by waste fractions. According to the contribution to the total activity value, NRN can be arranged in a row: 40К &gt; 226Ra &gt; 232Th. The most radiation-clear is the fraction &gt; 20 mm of the “Zaporizhstal” dump slag, the radioactivity of the fractions 1.25‒2.5 mm for DMC, 5‒10 and 0.63‒1.25 for MMC and the “ArcelorMittal” granulated slag is increased. All investigated slags belong to the first class of radiation hazard (Сef 370 Bq/kg) and can be used in construction without restrictions. Originality. All investigated slags correspond to international radiological indicators: Raeq 370 Bq/kg, radiation hazard indices are Iγ, Iex, Iin and Iα 1, which indicates that there is no danger of increased gamma radiation and emanation of radon and the daughter products of its decay into the room air. The concentration of radon indoors does not exceed 200 Bq/m3. For the average sample and slag fractions &lt;2.5 mm of “ArcelorMittal”, the activity utilization index which determines the safety of practical waste use is overestimated; the absorbed dose rate in the open air and the annual effective equivalent dose are higher than the world average values, they are, respectively, 58 nGy/h and 0.07 mSv, but at the same time below the value recommended by the IAEA for the population of 1 mSv/year. The excess lifetime carcinogenic risk for dispersed fractions of “ArcelorMittal” slag is higher than the world average: 0.29·10–3, but below the 0.05 limit set by the International Commission on Radiation Protection. A direct correlation between the acidity of the slag fractions and the increase in radiological parameters was determined. Practical value. An attempt has been made to relate the radioactivity of blast-furnace slag with the NRN sorption on the negatively charged surface of slag particles, which is more reliable for amorphous sorption-active granular slag.

Radon at Kilbourne Hole Maar and Magnetic and Gravimetric Correlations.

Soil radon gas concentrations ranging from the detection limit up to 15 kBq/m3 were measured for the first time at the Kilbourne Hole maar in two selected regions: the first region was located on the western volcanic field, and the second was located inside the crater, near the southern border. Radioactive anomalies were found in association with the pyroclastic deposit, and the corresponding heat map provided information on the radon diffusion direction by the CRn gradient. It was observed for the first time that the anomalies found at the southern border are associated with a known geological fault, in opposition to what was found on the western border. The results provided by a radon activity concentration gradient of above (8 kBq/m3)/15 m suggest the existence of a fault that has not been detected yet. The observation that high levels near a dormant fault are related to tectonically enhanced radon was confirmed. The activity concentrations of Rn-gas were contrasted to existing gravimetric and magnetic data to provide measuring information on radon emanation, suggesting the existence of a high, naturally occurring radioactivity in the soil in the first place or an increased porosity of the locally defined lithology. The results indicated a higher correlation of 85% with magnetic anomalies. This is in opposition to the gravimetric data, which was only 30%. This study is a contribution to the characterization maar of volcanic geology by the soil radon activity index, which was designated as "low" in this case.

Evolution of traceable radon emanation sources from MBq to few Bq

In the framework of the EMPIR project traceRadon, stable atmospheres with low-level radon activity concentrations have to be produced for calibrating radon detectors designed to measure outdoor air activity concentrations. The traceable calibration of these detectors at very low activity concentrations is of special interest to the radiation protection, climate observation, and atmospheric research communities.Radiation protection networks (such as the EUropean Radiological Data Exchange Platform (EURDEP)) and atmospheric monitoring networks (such as the Integrated Carbon Observation System (ICOS)) need reliable and accurate radon activity concentration measurements for a variety of reasons, including: the identification of Radon Priority Areas (RPA); improving the sensitivity and reliability of radiological emergency early warning systems (Melintescu et al., 2018); for more reliable application of the Radon Tracer Method (RTM) to estimate greenhouse gas (GHG) emissions; for improved global “baseline” monitoring of changing GHG concentrations and quantification of regional pollution transport (Chambers et al., 2016), (Chambers et al., 2018); and for evaluating mixing and transport parameterisations in regional or global chemical transport models (CTMs) (Zhang et al., 2021), (Chambers et al., 2019).To achieve this goal, low activity sources of radium with a variety of characteristics were produced using different methods. Sources ranging from MBq 226Ra down to several Bq 226Ra were developed and characterised during the evolution of production methods, and uncertainties below 2 % (k=1) were achieved through dedicated detection techniques, even for the lowest activity sources. The uncertainty of the lowest activity sources was improved using a new online measurement technique for which the source and detector were combined in the same device. This Integrated Radon Source Detector device, henceforth an IRSD, reaches a counting efficiency approaching 50 % through detection under quasi 2π sr solid-angle. At the time of this study the IRSD was already produced with 226Ra activities between 2 Bq and 440 Bq.To compare the working performance of the developed sources (i.e., to establish a reference atmosphere), study the stability of the sources, and to establish traceability to national standards, an intercomparison exercise was carried out at the PTB facility. Here we present the various source production techniques, the determination of their radium activity, and determination of their radon emanation (including assigned uncertainties). This includes details of the implementation of the intercomparison set-up, and a discussion of the results of the source characterisations.

Long-term vs. short-term measurements in indoor Rn concentration monitoring: Establishing a procedure for assessing exposure potential (RnEP)

Radon (Rn-222 or Rn) is a naturally occurring chemical element that belongs to the progeny of U-238 released from soil and rocks into the atmosphere, whose impact on organisms is not negligible when it occurs inside confined spaces, such as mine shafts or low-ventilated buildings. The current methodologies for indoor radon assessment are based on passive and active detection. If passive detectors are mainly designed for long-term assessment, active detectors are electronic equipment that can allow on-time visualization of results and, therefore, faster decision-making on risk mitigation measures implementation. However, despite offering a prompt and informed decision, the uncertainty associated with active detector results may cast doubt on the quality of the measurements, which especially arises from the duration of the monitoring campaign. Since radon emanation from soils and rocks depends on a set of variables related to meteorological parameters and soil structure, the seasonal variation of these parameters impacts indoor radon concentration assessment, both on short-term and long-term measurements. Therefore, short-term monitoring campaigns lasting a month, a week, or a day may not produce a statistically representative description of indoor radon exposure for the monitored building. Accordingly, the study compares the reliability of short-term and long-term indoor radon measurements. It proposes a procedure for assessing the indoor Radon Exposure Potential (RnEP) based on in situ measurements through the analysis of the frequency of occurrence of results divided into three classes of potential exposure (low, moderate and high) to reduce occupants' radon risk exposure.

Production and characterization of a 222Rn-emanating stainless steel source

Precise radon measurements are a requirement for various applications, ranging from radiation protection over environmental studies to material screening campaigns for rare-event searches. All of them ultimately depend on the availability of calibration sources with a known and stable radon emanation rate. A new approach to produce clean and dry radon sources by implantation of 226Ra ions into stainless steel has been investigated. In a proof of principle study, two stainless steel plates have been implanted in collaboration with the ISOLDE facility located at CERN. We present results from a complete characterization of the sources. Each sample provides a radon emanation rate of about 2 Bq, which has been measured using electrostatic radon monitors as well as miniaturized proportional counters. Additional measurements using HPGe and alpha spectrometry as well as measurements of the radon emanation rate at low temperatures were carried out.

Некоторые результаты работ по оценке эманаций радона Унальского хвостохранилища

Introduction. Despite the significant contribution of scientists to the study of the existing technogenic impact of the Unal tailing dump on the environment, studies on it of such parameters as the stress-strain state of the tailing dump body, radon emanation have not been previously studied. Materials and research methods. The purpose of the studies described in the work was to study the presence and magnitude of radon emanations in the subsoil air of the surface of the Unal tailing dump for further assessment of the applicability of the method to take into account the stress-strain state of the body. As a result of field studies, the authors measured the equivalent equilibrium volumetric activity of radon-222 (hereinafter EEVA) in the reference points selected according to the previously proposed algorithm for selecting reference points, which is based on the methodology for determining the stress-strain state of a body undergoing change. As a result of the studies, the values of radon emanation data were determined, the data obtained on EEDA were processed and systematized for subsequent analysis and evaluation using specialized software and algorithmic software. Research results. As a result of the analysis and evaluation of the obtained data on EEDA, after establishing the fact of the presence of radon emanations from the area, it can be concluded that it is necessary to conduct a second expedition in order to prove the hypothesis of the possible use of EEDA to assess and characterize the stress-strain state of the tailings body (in relation to the Unal tailings) and substantiate occurrence of serious consequences in case of a potential change in the state of the body of the tailing dump during seasonal flooding, seismic and technogenic impacts. In the course of this work on the analysis of the results of experimental studies in the scientific and educational center of the SFU branch in Gelendzhik and field studies, the following conclusions can be formulated. As a result of a number of research activities to assess the geo-ecological sustainability of tailings using seismic and satellite GPS equipment (including the justification of control well locations for monitoring radon emanations), the hypothesis was confirmed that the current values can be estimated from variations in changes in radon 222 emanations stress-strain state of the body of the tailing dump, which makes a significant contribution to the development of express methods for diagnosing the level of pollution of anomalous zones and assessing the risk for adjacent media using the latest geophysical, geochemical and geostatic methods. The proposed method for analyzing the stress-strain state of the tailing dump body and other parameters of its internal structure can also be used to monitor other alluvial and bulk man-made massifs formed as a result of the activities of mining and processing plants located in various regions of the Russian Federation.

The influence of building material structure on radon emanation

In this work, the radon emanation coefficients for selected building materials that are most often used in Serbia for covering floor surfaces (concrete, concrete screed, granite, glazed ceramic tiles, marble, roofing tile, and terrazzo tile) were determined, and the influence of the material structure on their values. The concentration of 226Ra activity in the samples was determined using the gamma spectrometry method. Radon emanation was measured with the RAD7 device. The porosity of the samples was tested using mercury intrusion porosimetry and water absorption methods, and the structural analysis was performed using x-ray diffraction analysis and x-ray fluorescence analysis. The measured values of 226Ra activity concentrations were in the range (4.93–298) Bq kg−1, and the estimated values of the radon emanation coefficients were in the range (0.55–6.05) %. The obtained results indicate that the chemical and mineralogical composition, method of production, and the 226Ra activity concentration have an influence on the emanation of radon from the material. No significant correlation was found between the radon emanation coefficient and the open porosity of the material, most likely due to the inhomogeneous presence of pores of different dimensions in the materials. It was established that the total value of the emanation coefficient depends on the emanation coefficient for pores ⩽100 μm in size.