Low Radon Concentrations Research Articles

Short-Term vs. Long-Term: A Critical Review of Indoor Radon Measurement Techniques.

Radon is a known carcinogen, and the accurate assessment of indoor levels is essential for effective mitigation strategies. While long-term testing provides the most reliable data, short-term testing (STT) offers a quicker and more cost-effective alternative. This review evaluated the accuracy of STT in predicting annual radon averages and compared testing strategies in Europe (where long-term measurements are common) and the United States (where STT is prevalent). Twenty (20) studies were systematically identified through searches in scientific databases and the grey literature, focusing on STT accuracy and radon management. This review revealed several factors that influence the accuracy of STT. Most studies recommended a minimum four-day test for initial screening, but accuracy varied with radon levels. For low levels (<75 Bq/m3), a one-week STT achieved high confidence (>95%) in predicting annual averages. However, accuracy decreased for moderate levels (approximately 50% success rate), necessitating confirmation with longer testing periods (3 months). High radon levels made STT unsuitable due to significant fluctuations. Seasonality also played a role, with winter months providing a more representative picture of annual radon averages. STT was found to be a useful method for screening low-risk areas with low radon concentrations. However, its limitations were evident in moderate- and high-level scenarios. While a minimum of four days was recommended, longer testing periods (3 months or more) were crucial for achieving reliable results, particularly in areas with potential for elevated radon exposure. This review suggests the need for further research to explore the possibility of harmonizing radon testing protocols between Europe and the United States.

Assessing radon adsorption capacity in adsorbents using solid state nuclear track detectors (SSNTDs)

Radon, specifically the isotope 222Rn, poses health risks, particularly in concentrated indoor environments. Recent years have underscored the significance of measuring low radon concentrations outdoors, offering crucial insights into radon priority areas and climate-related processes. To achieve the necessary high sensitivity, one approach involves placing radiation detectors in close proximity to efficient radon adsorbers that function as radiators. While activated charcoal has been employed for over a century, recent years have seen the production of highly efficient synthetic adsorbents and activated carbon materials. A vital parameter essential for designing and modeling sensitive radon detectors/monitors is the adsorption capacity of the adsorbent for radon. This study introduces a simple and cost-effective method enabling the determination of the adsorption capacity of numerous prospective adsorbents simultaneously. The method entails placing SSNTDs in close contact with the adsorbent to generate tracks from the alpha particles emitted by adsorbed 222Rn and its progeny. A theoretical model is presented, facilitating the determination of adsorption capacity using SSNTDs with a well-defined response function to alpha particles. Experimental validation involves comparing theoretical estimates with published data from studies on activated charcoals, demonstrating very good agreement. The method's versatility is underscored by its application to activated carbon fabrics, showcasing its potential to optimize detector designs for enhanced sensitivity. This proposed approach holds promise for advancing radon monitoring technology, contributing to improved risk assessment and environmental studies related to radon.

Measurement and characteristics of radon flow in an extremely arid region based on a closed-system earth-air model

Radon (222Rn) is a radioactive gas that occurs naturally in the soil and is harmful to the environment and health. However, the measuring the amount of radon flowing is challenging. This study reveals the mechanism responsible for radon transportation and concentration variation, the main driving forces acting, and the key factors operating in the vadose zone. In this study, two separate holes were used to monitor the amount of earth-air and radon flowing in and out of the soil in the extremely arid region in China where the Mogao Grottoes are located. Using a closed-system model, the quantity, characteristics, and regularity of the flow of earth-air and radon were thus determined on daily and yearly timescales. The same patterns of variation in earth-air flow and radon concentration were found at the two sites, both depending on the variation in the atmospheric pressure (AP). When the AP decreases, earth-air flows out from the soil with a high radon concentration. Conversely, when the AP increases, earth-air enters into the soil with a low radon concentration. Thus, radon is continuously emitted from the soil. The concentration of radon in the earth-air is proportional to the rate of flow of earth-air and therefore increases as the AP decreases. The radon emission also varies with the seasonal variation in temperature and AP, which is high in summer and low in winter. On a daily timescale, the radon varies in a bimodal manner. Therefore, the net amount of radon emitted from the soil is positively correlated with the amplitude of the AP fluctuation, temperature, soil porosity, and thickness of the vadose zone. The atmospheric pumping is the main driving force responsible for the radon emission. However, the surface closure, landform, cracks, faults, grain size, pore structure, soil adsorption, basal uranium/radium, salts, wind, lunar cycle, latitude and altitude have important effects on the number of radon emission. As such, it provides a scientific basis for the effective utilization of radon and prevention of its emission from soil.

Environmental radon control in the 700 m underground laboratory at JUNO

The Jiangmen Underground Neutrino Observatory is constructing the world’s largest liquid scintillator detector, with a 20 kt target mass and approximately 700 m of overburden. The total underground space of civil construction is around 300,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}, with the main hall comprising about 120,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}, making it the largest experimental hall in the world. Maintaining a low radon concentration in the underground air is crucial for both human health and the accuracy of experiments involving rare decay detection, such as neutrino and dark matter experiments. To ensure human health and the integrity of neutrino physics experiments, the nominal radon concentration in the main hall must be kept below 200 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document} with a maximum value below 400 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}. Introduction of fresh air from above ground can significantly lower radon concentration. A benchmark experiment conducted in the refuge room near the main hall revealed that the radon emanating from underground water is a significant source of radon in the underground air. The total underground ventilation rate is approximately 160,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}/h of fresh air with about 30 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}222\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{222}$$\\end{document}Rn from the bottom of the vertical tunnel after the installation of powerful fans. Of this, 55,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}/h is used for ventilation in the main hall. As a result of these measures, the radon concentration inside the main hall has decreased from 1600 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document} to below 200 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document} under stable working conditions, with exceptions during rare adverse weather events or fan failures. The employed strategies to control radon concentration in the underground air are described in this paper.

P1106 Is indoor radon associated with new diagnosis of inflammatory bowel disease patients?

Abstract Background Inflammatory Bowel Diseases (IBD) are a group of pathologies of unknown etiology associated with some environmental factors, only partially identified. The role of indoor radon, a radioactive gas, has not been formally studied and it might play a role on the onset of the disease. The aim of this study is to analyze the role of individual residential radon exposure on the incidence of IBD in a radon-prone area also characterized as a high incidence IBD region. Methods A case-control study was developed in the health area of Santiago de Compostela (Galicia, Spain) between June 2020 and September 2023, including incident cases with IBD. Controls were selected trough a frequency matching based on sex and age and without IBD. All participants had to be living at least 5 years in the same dwelling, those with a change of address in the last 5 years prior to diagnosis were excluded. Endoscopic index, imaging techniques and analytic parameters were collected. Radon levels measured over three months in the participants’ home were compared between cases and controls, and between the different types of IBD. Each individual was provided with a residential radon meter (a RSKS trace detector), given and read by the Galician Radon Laboratory, a certified radon laboratory. Procedure is summarized in Figure 1. Radon concentrations were categorized into three groups, 0-99 Bq/m3, 100-299 Bq/m3 and &amp;gt;299 Bq/m3. Results are expressed as Odds Ratios with their 95%CI obtained through logistic regression. Results 178 incident cases and 178 controls (102 ulcerative colitis, 70 Crohn’s disease and 6 unclassified colitis) were included, with a median age of 51 years old (IQR 40 – 59.5). 51.7% were females. Median radon levels of IBD patients´ homes were 144.5 (IQR 83 – 260) and median radon levels of controls´ homes were 189.5 (IQR 112 – 292.5) (figure 1). Adjusting by age and sex, high radon levels showed a negative association for the development of IBD (taking levels of 0-99 Bq/m3 as reference, OR 100-299 Bq/m3 is 0.5 (95%CI 0.3-0.8), and OR &amp;gt;299 Bq/m3 is 0.5 (95%CI 0.3-0.9). Results are shown in table 1. Analyzing women and men separately, there are no statistically significant differences (p&amp;gt;0.05 in each group). Taking into account the different types of IBD, radon levels show the same negative association but without statistical association. Conclusion High radon levels might be a protective factor for developing IBD overall and its most common types, Crohn’s disease and ulcerative colitis. Further studies in other areas with lower radon concentrations will be necessary to corroborate whether it influences the incidence of IBD.

Performance evaluation of radon active sensors and passive dosimeters at low and high radon concentrations

Radon is a naturally occurring radioactive gas that has the potential to accumulate in buildings and over time, causes lung cancer in humans. Present methods for radon measurements are disparate, which pose challenges to benchmark radon concentrations and to accurately assess the population's received dose. This paper presents a comprehensive performance evaluation of radon dosimeters and three grades of active radon sensors: consumer-, medium- and research-grade. The measurements were performed at relatively low (300 Bq/m3) and high (2′000–3′000 Bq/m3) radon levels. Tests were conducted in an atomic shelter, with stable temperature and humidity conditions. The active sensors differed in absolute accuracy and dynamic performance (time-dependent correlations) according to their grade. Research-grade sensors performed marginally better than medium-grade sensors, and significantly better than consumer-grade sensors. Relative to the reference, the error (percentage difference between the reference and the sensors) was below 5 % for research- and medium-grade sensors, and nearly 10 % for consumer-grade sensors at high radon levels. Performance of sensors diminished at low radon levels, except for research-grade sensors. Passive dosimeters generally performed better at high radon levels than at low ones. Their longer exposure time was associated with increased measurement reliability. These results highlight the need for understanding the purpose of measurements in order to select an adequate radon detector, and ultimately, reduce measurement and interpretation errors. This study raises awareness among researchers, radon professionals and the general public regarding the performances of different active radon sensors and passive dosimeters. It also sheds light on their respective scope of application.

Distribution of Radionuclides in the Surface Covering of the Barun Uranium Mining Area in Erlian Basin, Inner Mongolia

In order to identify the distribution pattern of radionuclides in the surface soil in the area of a sandstone-type uranium deposit, and to explore its spatial relationship with the location of the orebody, soil radon measurements and ground gamma-ray spectroscopy were carried out in the Barun study area, and soil properties were analyzed. The results show that the soil radon concentrations exhibited a bimodal feature, while the uranium content showed a decreasing trend along the tendency direction of the orebody. In the ground projection area of the orebody, radon concentration showed a positive correlation with uranium content, with both showing relatively low values. Combined with the results of field geological observation and soil property analysis, it is believed that the relatively low radon concentration and uranium content above the orebody is related to the soil being mainly sandy soil. Relatively high uranium values are distributed within approximately 1.5 km north of the northern boundary of the orebody and near the southern boundary of the orebody. High-value radon anomalies occur within about 2 km north of the northern boundary of the orebody and within about 1.3 km south of the southern boundary of the orebody.

Metrology infrastructure for radon metrology at the environmental level

Since 2020 a large consortium has been engaged in the project EMPIR 19ENV01 traceRadon to develop the missing traceability chains to improve the sensor networks in climate observation and radiation protection. This paper presents results in the areas of: Novel 226Ra standard sources with continuous controlled 222Rn emanation rate, radon chambers aimed to create a reference radon atmosphere and a reference field for radon flux monitoring. The major challenge lies in the low activity concentrations of radon in outdoor air from 1 Bq∙m-3 to 100 Bq∙m-3, where below 100 Bq∙m-3 there is currently no metrological traceability at all. Thus, measured values of different instruments operated at different locations cannot be compared with respect to their results. Whin this paper, new infrastructure is presented, capable of filling this gap in traceability. The achieved results make new calibration services, far beyond the state of art, possible.

Radon concentration in groundwater of north-eastern Sicily (Italy)

This paper presents analyses of 222Rn activity concentration performed on groundwater samples collected from wells and natural springs in 70 different sites of the crystalline area of north-eastern Sicily (southern Italy), up to now poorly studied. Alpha spectroscopy of the short-lived radon progeny was used to measure the 222Rn activity concentration by means of the Durridge RAD7 + H2O setup. Radon concentrations were derived to be in the range of 1.6–57.5 Bq L-1. The higher values were detected along fluvial valleys and in the crystalline reliefs, whereas aquifers hosted in the alluvial plains show lower radon concentrations. The annual effective dose due to intake of radon by ingestion ranges from 4 to 146.8 μSv y-1. The average value (56.5 μSv y-1) is below the recommended limit of 100 μSv y-1 proposed by the World Health Organization (WHO). In addition, all the measured radon values are lower than the reference level of 100 Bq L-1 set by the Italian legislative decree 28/2016 and by the European Directive 2013/51/Euratom. Therefore, all sampling sites are fully compliant with the legislative requirements in terms of radon levels. Moreover, results show that the radon levels measured in groundwater from north-eastern Sicily are similar to those determined for the adjacent area of southern Calabria, promoting the assumption of a uniform radon signature in the crystalline domain of southern Italy. However, further studies are needed to define better the role of tectonic activity on the content of dissolved radon in groundwater.

Origin and transport of radon in a dry and in a wet mofette of COVASNA, Romania

The appearances of significant efflux of carbon dioxide through soil surfaces is a frequent natural phenomena in the wider vicinity of relatively young volcanic fields. These mofettes are often utilised as dry carbon dioxide spas to treat patients suffering from cardiovascular diseases. The carbon dioxide always carries some naturally occurring radioactive radon gas with it. On the one hand this radon gas might pose some radiation risk for the patients and staff of such carbon dioxide spas, on the other hand it may be used as a natural tracer for the study of transport of its carrier gas in the subsurface and in the pools. In this work we have measured the spatial variation of radon activity concentration in the gas phase of the carbon dioxide gas pool of the Cardiology Hospital and in the gas and water phases of the Hell-Mud, which is a wet open pit mofette in the city of Covasna. We have developed a hydro- and gas-geological conceptual and mathematical model with which we were able to describe the measured spatial and temporal behaviour of radon gas concentration. We have found that the relatively low radon concentrations at the bottom of these pools can be explained by removing the radon content of water by intense bubbling degassing of the oversaturated carbonated waters.

Radon daughter's radioactivity levels in the Arabian Sea as indicators of airmass mixing

Measurements on radon daughter's activities in the Arabian Sea were carried out during the period 19 May to 9 July 1973, under the joint Indo-USSR MONEX-73 project. The data were collected on board the ships of the Indian Navy cruising between 19°N- 21°N, within longitudes 60°E- 73°E and the two USSR vessels Okean and Priliv cruising between latitudes 0°-10°N and 10°N-18°N, respectively. The results show that there is a significant increase in radon daughter's activity at about 19°N-21°N, the average level being of the order of about 8 pci/m3 as compared to 1-2 pci/n13 at lower latitudes. This is explained, on the basis of synoptic charts and available sounding data, as being due to the wind and pressure pattern prevailing during the monsoon months which result in the transport of continental -air from Arabia and Pakistan and its mixing with the maritime monsoon airmass of southern hemispheric origin. The significant increase .in radon activity on some days of the cruise was mainly due to the existence of disturbances like depressions, cyclonic storms, etc, over the north Arabian Sea, or due to the passage of Western disturbances at a relatively lower latitudes (along approximately 25°N) and their associated circulation patterns. These phenomena favour significant transport of continental air from the north a~ west. The mixing of this continental airmass with the airmass of low radon concentrations results in increasing the average randon levels from 1 to 8 pci/m3.

New generation of highly sensitive radon detectors based on activated carbon with compensated temperature dependence

Recently patented compensation module for sensors of radioactive noble gases paves the way for novel designs of radon detectors/monitors with adsorbents, suitable for long-term measurements. The module compensates the strong influence of the temperature on the response of detectors with activated carbon or other ad/absorbents. This report describes radon detectors in which activated carbon fabric is coupled with a solid state nuclear track detector and placed in a compensation module. The module is a hermetic volume made of polyethylene foil, through which the radon diffuses. Two reciprocal trends make possible the temperature compensation: that of the radon penetration through the walls, which increases with the increase of the temperature, and that of the adsorption, which decreases. The results show that outside the module the variation of the detector response over the range of 5–35 °C is 230–305%. In contrast, inside the module the variation is reduced to 6–17%. The module also protects the sensor from humidity and thoron, keeping its sensitivity to radon 7–9 times higher than that of commonly used radon detectors. This makes the new detectors very useful for measurement of low radon concentrations in the atmosphere.

Indoor Air Radon Concentration in Premises of Public Companies and Workplaces in Latvia.

Considering the multitudes of people who spend their time working indoors in public premises and workplaces, it is worth knowing what their level of exposure is to natural radioactive radon gas, the second most widespread and dangerous carcinogen for lung cancer development after cigarette smoking. This state-level study covered most of the territory of Latvia and conducted 941 radon measurements with Radtrack2, placed for 4–6 months in the premises of public companies, educational institutions, medical care institutions, etc. The study found that 94.7% of samples did not exceed the national permissible limit (200 Bq/m3), the level at which preventive measures should be initiated. The median value of average specific radioactivity of radon in these premises was 48 Bq/m3 (Q1 and Q3 being 27 and 85 Bq/m3), which is below the average of the European region. Slightly higher concentrations were observed in well-insulated premises with plastic windows and poorer air exchange, mostly in schools (59 (36, 109) Bq/m3) and kindergartens (48 (32, 79) Bq/m3). Industrial workplaces had surprisingly low radon levels (28 (16, 55) Bq/m3) due to strict requirements for air quality and proper ventilation. Public premises and workplaces in Latvia mostly have low radon concentrations in the air, but more attention should be paid to adequate ventilation and air exchange.

Pilot groundwater radon mapping and the assessment of health risk from heavy metals in drinking water of southwest, Nigeria

Radon and heavy metals are sources of groundwater pollution and are identified as potential carcinogens. Southwest Nigeria's populace mostly relies on groundwater source for drinking. This study aims to map radon distribution in groundwater of southwest Nigeria and to determine the health risk of radon and heavy metal in drinking water. Radon concentrations of 145 groundwater samples were measured using RAD7 electronic radon detector and heavy metal concentrations of 52 groundwater samples were measured using atomic absorption spectrophotometer. Radon concentration distributions were delineated using geographical information system. Radon concentration of water samples ranges between 1.6 Bq l−1 and 271 Bq l−1 with an average value of 35.9 ± 38.4 Bq l−1. The average groundwater radon concentration is higher than US-EPA recommended level of 11.1 Bq l−1 but lower than the WHO recommended limit of 100 Bq l−1. The estimated average annual effective radiation doses to infants, children, and adults are 29 μSvy−1, 41 μSvy−1 and 92 μSvy−1 respectively. The radon distribution map of the study area reveals regions of high, medium, and low groundwater radon concentrations. The average concentration values of heavy metals in groundwater samples are of the order Mn > Zn > Pb > Cu > Cr > Ni > Cd. 84% of groundwater exhibits good to excellent quality in terms of heavy metal pollution. However, about 16% of the samples which lie in the sedimentary regions of Ogun and Lagos States exhibit poor to very poor quality. Overall, ingestion of groundwater in the study area may not pose a serious health hazards from radon ingestion and heavy metal toxicity.

Inter-comparison of commercial continuous radon monitors responses

Indoor and outdoor (atmospheric) radon activity concentrations need to be measured as accurate as possible for radiation protection and for climate applications. Particularly radon concentrations below 100 Bq m −3, useful for the retrieval of radon prone areas and for atmospheric studies, still need a robust metrological chain to ensure their quality. Ones of the most common used commercial continuous radon monitors were compared here under slightly different environmental conditions. The measured data set were divided into two groups (< 100 Bq m −3 and ≥ 100 Bq m −3) to assess the monitors responses and their associated uncertainties. Nevertheless, these results should also to point out if commercial monitors are suitable for monitoring low atmospheric radon concentrations with an associated uncertainty of 10% (k=1). This work, carried out within the EMPIR 19ENV01 traceRadon project, aims to offer a starting point for the development of a future radon monitor as transfer standard to increase the metrological capabilities of atmospheric radon monitoring.

A comparative study of genotoxicity endpoints for women exposed to different levels of indoor radon concentrations

Background and purpose Radon and its radioactive progenies are the most important source of ionizing radiation of natural origin, being classified as a Group 1 carcinogen. The aim of this study is to investigate the genotoxic effects of a wide range of indoor radon concentrations, as well as the kinetics of the process of repairing DNA-induced lesions by a challenging dose of gamma irradiation. Material and methods Female subjects residing in the Băiţa-Ştei radon priority area were selected as the exposed group. The reference group was comprised of women from the same county (Bihor), but located in an area with an average indoor radon concentration typical of the county from which they were taken. Radon concentration values of 300 Bq/m3 and 148 Bq/m3, respectively, were chosen as a threshold in order to capture the impact of radon exposure between the groups. The alkaline comet assay was used in order to measure the DNA damage, as well as the repair kinetics at 2 and 24 h after 2 Gy challenging doses of gamma irradiation using peripheral blood lymphocytes. From the serum of the subjects, the oxidative damage by 8-hydroxydeoxyguanosine as well as the PARP induction was evaluated. The chromosomal aberrations were evaluated using the Cytokinesis Block MicroNucleus Assay. Results A statistically significant increase was observed in terms of DNA-induced lesions assessed by comet assay for the exposed group compared to the reference group. A positive correlation was obtained between DNA damage and the annual effective dose, respectively with the radon progenies concentrations. A statistically significant difference was also observed for the frequency of the micronuclei between the exposed – reference groups. Significantly faster repair kinetics of DNA-induced lesions was recorded for the first 2 h after gamma irradiation in the reference group compared to the exposed group. Using the threshold of 300 Bq/m3 for radon concentration, faster kinetics of DNA damage repair for people exposed to low radon concentrations, compared to those exposed to higher concentrations for the second phase of DNA repair kinetics was observed. Conclusion An increased radiosensitivity of lymphocytes, as well as slower repair kinetics, may be associated with exposure to higher indoor radon concentrations.

Local radon flux maxima in the quaternary sediments of Schleswig\u2013Holstein (Germany)

This paper presents radon flux profiles from four regions in Schleswig–Holstein (Northern Germany). Three of these regions are located over deep-rooted tectonic faults or salt diapirs and one is in an area without any tectonic or halokinetic activity, but with steep topography. Contrary to recently published studies on spatial patterns of soil radon gas concentration we measured flux of radon from soil into the atmosphere. All radon devices of each profile were deployed simultaneously to avoid inconsistencies due to strong diurnal variations of radon exhalation. To compare data from different seasons, values had to be normalized. Observed radon flux patterns are apparently related to the mineralogical composition of the Quaternary strata (particularly to the abundance of reddish granite and porphyry), and its grain size (with a flux maximum in well-sorted sand/silt). Minimum radon flux occurs above non-permeable, clay-rich soil layers. Small amounts of water content in the pore space increase radon flux, whereas excessive water content lessens it. Peak flux values, however, are observed over a deep-rooted fault system on the eastern side of Lake Plön, i.e., at the boundary of the Eastholstein Platform and the Eastholstein Trough. Furthermore, high radon flux values are observed in two regions associated with salt diapirism and near-surface halokinetic faults. These regions show frequent local radon flux maxima, which indicate that the uppermost strata above salt diapirs are very inhomogeneous. Deep-rooted increased permeability (effective radon flux depth) or just the boundaries between permeable and impermeable strata appear to concentrate radon flux. In summary, our radon flux profiles are in accordance with the published evidence of low radon concentrations in the “normal” soils of Schleswig–Holstein. However, very high values of radon flux are likely to occur at distinct locations near salt diapirism at depth, boundaries between permeable and impermeable strata, and finally at the tectonically active flanks of the North German Basin.

Study on the relationship between radon characteristics of underground water and seismicity in the Longxian - Baoji fault zone, NW China

Destructive earthquakes are mostly located in the active fault zones. The underground gas anomalies result to basically be consistent with the inferred distribution of active fault systems. Among them, radon is the earliest used as the effective prediction index of fault zone earthquake prediction. In this paper, radon concentrations in groundwater from the Longxian – Baoji fault zone in the Northwestern China are analyzed. Results show that the NW sector has a lower radon concentration (∼12 Bq/L) than that of the SE sector (40 ∼ 50 Bq/L). It indicated that the connectivity between the shallow and deep crust is relatively poor in the NW sector, which is not conducive to the upward diffusion and migration of deep fluids. Given that there is a seismic gap with no rupture of M ≥ 61/2 strong earthquake in the NW sector, it can be infered that the NW sector of the Longxian - Baoji fault zone has a higher risk of strong earthquakes than that in the SE sector.

National comparison of methods for determination of radon in water

Abstract The article describes three interlaboratory experiments concerning 222Rn determination in water samples. The first two experiments were carried out with the use of artificial radon waters prepared by the Laboratory of Radiometric Expertise (LER), Institute of Nuclear Physics, Polish Academy of Sciences in Kraków in 2014 and 2018. The third experiment was performed using natural environment waters collected in the vicinity of the former uranium mine in Kowary in 2016. Most of the institutions performing radon in water measurements in Poland were gathered in the Polish Radon Centre Network, and they participated in the experiments. The goal of these exercises was to evaluate different measurement techniques used routinely in Polish laboratories and the laboratories’ proficiency of radon in water measurements. In the experiment performed in 2018, the reference values of 222Rn concentration in water were calculated based on the method developed at LER. The participants’ results appeared to be worse for low radon concentration than for high radon concentrations. The conclusions drawn on that base indicated the weaknesses of the used methods and probably the sampling. The interlaboratory experiments, in term, can help to improve the participants’ skills and reliability of their results.

Radon-222: environmental behavior and impact to (human and non-human) biota.

As an inert radioactive gas, 222Rn could be easily transported to the atmosphere via emanation, migration, or exhalation. Research measurements pointed out that 222Rn activity concentration changes during the winter and summer months, as well as during wet and dry season periods. Changes in radon concentration can affect the atmospheric electric field. At the boundary layer near the ground, short-lived daughters of 222Rn can be used as natural tracers in the atmosphere. In this work, factors controlling 222Rn pathways in the environment and its levels in soil gas and outdoor air are summarized. 222Rn has a short half-life of 3.82days, but the dose rate due to radon and its radioactive progeny could be significant to the living beings. Epidemiological studies on humans pointed out that up to 14% of lung cancers are induced by exposure to low and moderate concentrations of radon. Animals that breed in ground holes have been exposed to the higher doses due to radiation present in soil air. During the years, different dose-effect models are developed for risk assessment on human and non-human biota. In this work are reviewed research results of 222Rn exposure of human and non-human biota.