Low Radon Research Articles

Detector upgrade for 222Rn concentration in high purity nitrogen measurement

To ensure the low background of the Jiangmen Underground Neutrino Observatory (JUNO) detector, high purity nitrogen (HPN) is used as a cover gas in direct contact with the liquid scintillator, which serves as the target material for neutrinos. The radon concentration in this nitrogen should be less than 10 μBq/m3. Given the background of the old detector, which is 2.20 ± 0.64 mBq/m3, combined with its enrichment efficiency of 51.0 % at a flow rate of 25 standard liters per minute (SLM), the effective measurement of radon concentrations below 10 μBq/m3 in HPN is a major challenge. A highly sensitive radon detector was upgraded to measure the radon concentration in HPN. A low background radon detection chamber was constructed based on the method of electrostatic collection and electrolytic polishing of low background steel with an internal surface roughness of ≤ 0.2 μm. The background of the radon detection chamber was reduced to 1.47 ± 0.19 mBq/m3. An automatic enrichment system based on 472 g low background activated carbon was developed. The introduction of a large amount of activated carbon has led to a significant increase in the enrichment flow rate to 200 SLM. In addition, the enrichment efficiency of the system simultaneously improved to 71 %. The relationship between the collection efficiency of the detection chamber and the applied voltage was calibrated. The result measured with this detector, shows that the radon concentration in HPN is 2.38 ± 0.30 μBq/m3.

The correlation between indoor and soil gas radon concentrations in Kiraz district, İzmir.

All humans are exposed to radon, the primary source of natural radiation, which can harm people due to natural processes rather than human activity. Thus, it is of significant importance to determine the levels of radon in indoor, soil gas, water, and outdoors. Radon concentration (CRn) was measured in Kiraz district, İzmir, and the correlation between the indoor and soil gas CRn values was investigated. The indoor CRn values measured in 40 randomly selected dwellings in Kiraz exhibited a wide range from 19.50 ± 2.50 to 204.70 ± 8.00Bqm-3 with an average value of 61.11 ± 4.23Bqm-3. The measured indoor CRn values were compared to the reference levels in the world to help control radon in the dwellings. Indoor CRn values were lower than the ICRP reference level of 300Bqm-3 in all of the dwellings studied. Furthermore, in 34 dwellings (representing 85% of the total number of dwellings studied), indoor CRn values were lower than the WHO reference level of 100Bqm-3. Health hazard indices, namely annual effective dose (AED) and excess lifetime cancer risk (ELCR), were also calculated for each dwelling and compared with internationally acceptable levels to estimate the risk to human health. The AED values varied from 0.49 ± 0.06 to 5.16 ± 0.20mSv y-1 with an average value of 1.54 ± 0.11mSv y-1, which exceeds the world average of 1.15mSv y-1 as reported by UNSCEAR. The ELCR values ranged from 2.05 ± 0.26 × 10-3 to 21.55 ± 0.84 × 10-3 with an average value of 6.43 ± 0.44 × 10-3, exceeding the world average of 0.29 × 10-3 as reported by UNSCEAR. The soil gas CRn values measured exhibited a wide variation ranging from 129.25 ± 6.38Bqm-3 to 6172.64 ± 44.06Bqm-3 with an average value of 1291.79 ± 18.70Bqm-3. The soil gas CRn values were less than 10,000Bqm-3; hence, the research area is categorized as "low radon risk areas" according to Sweden Criteria, and so no special constructions are required in the studied area. When soil gas CRn values were compared to indoor CRn values, no linear relationship was found between the CRn values. However, a strong positive linear correlation was found between indoor and soil gas CRn values less than 200Bqm-3 and 2500Bqm-3, respectively.

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.

The sensitivity of innovative techniques for measuring low levels of radon in the environment using passive detectors

In recent years, there has been a significant surge in interest in measuring low radon levels in the environment. These measurements are valuable, particularly for identifying radon priority areas as required by the European Council Directive 2013/59/EURATOM and for research related to climate change. Due to the limited sensitivity of existing radon detectors/monitors in addressing these challenges, substantial efforts have been devoted to developing new designs. This report compares the sensitivity of several innovative designs with that of existing passive radon monitors. These novel designs incorporate alpha track detectors, including large area low background detectors, with activated carbon fabric used as an efficient radon adsorber/radiator. Recent innovative solutions to mitigate the impact of temperature and humidity on detectors using adsorbers are also discussed. The background signal of detectors intended for use in these novel designs is examined, and their sensitivity is evaluated. The findings demonstrate that these novel designs have the potential to significantly enhance the sensitivity of long-term radon measurements, surpassing the detectors currently in widespread use by more than an order of magnitude.

Neighborhood-level socioeconomic disparities in Radon testing in North Carolina from 2010 to 2020

Radon is a naturally occurring radioactive gas that poses significant health risks to humans, including increased risk of lung cancer. This study investigates the association of neighborhood-level socioeconomic variables with radon testing and radon exposure levels in North Carolina between 2010 and 2020. Our analysis of the two largest commercial household radon tests reveals that 67% of census tracts had testing rates below 10 tests per 1000 population, indicating low testing prevalence. Low radon levels (<2 pCi/L) were detected in 74.1% of the tracts (n = 1626), while medium levels of 2–4 pCi/L and ≥4 pCi/L were observed in 17.2% (n = 378) and 1.6% (n = 36) of the tracts. A generalized spatial regression model was employed to analyze the association between neighborhood-level socioeconomic variables and radon testing rates (per 1000 households), controlling for median radon testing results. The results show a positive correlation (P-value <0.001) of testing rate with various indicators of neighborhood affluence including education level, income, and occupation. In contrast, neighborhood disadvantage, including poverty, unemployment, and public assistance, was associated with a lower radon-testing rate (P-value <0.001). These findings highlight the need for targeted interventions to address socioeconomic disparities in radon testing and promote awareness and access to testing resources in lower socio-economic neighborhoods. Improving testing rates can effectively address radon-related health risks in North Carolina and across the U.S.

Evaluating the impact of indoor aerosols on the performance of real-time radon sensors

Radon, a naturally occurring radioactive gas, poses a significant health risk by accumulating in buildings and potentially leading to lung cancer. Depending on building construction and geographical location, radon levels can vary substantially both within individual buildings and between different buildings. While previous studies have primarily focused on the impact of temperature and relative humidity on radon devices, the influence of aerosols remains largely unexplored. This paper presents a comprehensive evaluation of the influence of indoor aerosol sources on the performance of real-time radon sensors, encompassing consumer, medium, and research-grade devices. Measurements were performed at relatively low (300 Bq/m3) and high (2′000–3′000 Bq/m3) radon levels in a controlled environment—a stable atomic shelter with constant temperature and humidity conditions. Six different aerosols sources were introduced to produce aerosols of different sizes and concentrations. The results suggest that the tested indoor aerosols did not significantly influence the performance of radon devices, irrespective of their grade or detection method. Consequently, sensor performance and the radon levels being investigated may exert a more significant influence on the obtained results than aerosol levels alone. This paper provides valuable insights into the influence of indoor environment on the performance of radon measuring devices, underscoring the importance of understanding their utility and application scope for researchers, professionals, and the general public alike.

Everyday home radon exposure is associated with altered structural brain morphology in youths

The refinement of brain morphology extends across childhood, and exposure to environmental toxins during this period may alter typical trends. Radon is a highly common radiologic toxin with a well-established role in cancer among adults. However, effects on developmental populations are understudied in comparison. This study investigated whether home radon exposure is associated with altered brain morphology in youths. Fifty-four participants (6–14 yrs, M=10.52 yrs, 48.15% male, 89% White) completed a T1-weighted MRI and home measures of radon. We observed a significant multivariate effect of home radon concentrations, which was driven by effects on GMV. Specifically, higher home radon was associated with smaller GMV (F=6.800, p=.012, ηp2=.13). Conversely, there was a trending radon-by-age interaction on WMV, which reached significance when accounting for the chronicity of radon exposure (F=4.12, p=.049, ηp2=.09). We found that youths with above-average radon exposure showed no change in WMV with age, whereas low radon was linked with normative, age-related WMV increases. These results suggest that everyday home radon exposure may alter sensitive structural brain development, impacting developmental trajectories in both gray and white matter.

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.

Radon Exposure and Incident Stroke Risk in the Women's Health Initiative.

Little is known about the role of radon in the epidemiology of stroke among women. We therefore examined the association between home radon exposure and risk of stroke among middle-aged and older women in the United States. We conducted a prospective cohort study of postmenopausal women aged 50-79 years at baseline (1993-1998) in the Women's Health Initiative. We measured exposures as 2-day, indoor, lowest living-level average radon concentrations in picocuries per liter (pCi/L) as estimated in 1993 by the US Geological Survey and reviewed by the Association of American State Geologists under the Indoor Radon Abatement Act. We used Cox proportional hazards models to estimate risk of incident, neurologist-adjudicated stroke during follow-up through 2020 as a hazard ratio and 95% CI, adjusting for study design and participant demographic, social, behavioral, and clinical characteristics. Among 158,910 women without stroke at baseline (mean age 63.2 years; 83% white), 6,979 incident strokes were identified over follow-up (mean 13.4 years). Incidence rates were 333, 343, and 349 strokes per 100,000 woman-years at radon concentrations of <2, 2-4, and >4 pCi/L, respectively. Compared with women living at concentrations <2 pCi/L, those at 2-4 and >4 pCi/L had higher covariate-adjusted risks of incident stroke: hazard ratio (95% CI) 1.06 (0.99-1.13) and 1.14 (1.05-1.22). Using nonlinear spline functions to model radon, stroke risk was significantly elevated at concentrations ranging from 2 to 4 pCi/L (p = 0.0004), that is, below the United States Environmental Protection Agency Radon Action Level for mitigation (4 pCi/L). Associations were slightly stronger for ischemic (especially cardioembolic, small vessel occlusive, and large artery atherosclerotic) than hemorrhagic stroke, but otherwise robust in sensitivity analyses. Radon exposure is associated with moderately increased stroke risk among middle-aged and older women in the United States, suggesting that promulgation of a lower Radon Action Level may help reduce the domestic impact of cerebrovascular disease on public health.

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.

Methodology for assessment of radon diffusion coefficients in membranes, used as radon barriers in construction and refurbishment

In the near future, research on new materials for radon barriers can be expected to rise in order to meet a greater demand of radon mitigation solutions because of the increasingly lower radon levels that the EU legislation aims to. Such research would need a method for the determination of the radon diffusion coefficient and this paper presents an inexpensive method for that purpose, using affordable radon detectors and a simple experimental setup that does not require any tubing or any pumping. Besides the use of two Electronic Integration Devices as radon detectors, the experimental setup used in our method consists only in a two-chamber container made of steel and a small-sized radon source, which was produced in our lab using a 226Ra solution. The radon diffusion coefficient is determined by measuring radon levels in both chambers of the container, which are separated by a membrane made of the material whose radon diffusion coefficient is to be determined. Radon diffuses from a source chamber to a receiver chamber trough the membrane, being the amount of radon that has passed through and the rate at which it has done so the key parameters in the calculation of the radon diffusion coefficient. Our method can handily measure materials with a radon diffusion coefficient above or equal to 10-11 m2 s-1 or, provided that the sample is thin enough, verify that the coefficient is lower than 10-12 m2 s-1. Its precision is good enough to provide radon coefficient diffusion values with a good repeatability as the RSD is as low as a 35% for materials in which the coefficient is in the order of 10-11 m2 s-1. This means that our method is valid for screening materials for radon barriers and checking their compliance with technical specifications.

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.

Lifetime excess absolute risk for lung cancer due to exposure to radon: results of the pooled uranium miners cohort study PUMA

The Pooled Uranium Miners Analysis (PUMA) study is the largest uranium miners cohort with 119,709 miners, 4.3 million person-years at risk and 7754 lung cancer deaths. Excess relative rate (ERR) estimates for lung cancer mortality per unit of cumulative exposure to radon progeny in working level months (WLM) based on the PUMA study have been reported. The ERR/WLM was modified by attained age, time since exposure or age at exposure, and exposure rate. This pattern was found for the full PUMA cohort and the 1960 + sub-cohort, i.e., miners hired in 1960 or later with chronic low radon exposures and exposure rates. The aim of the present paper is to calculate the lifetime excess absolute risk (LEAR) of lung cancer mortality per WLM using the PUMA risk models, as well as risk models derived in previously published smaller uranium miner studies, some of which are included in PUMA. The same methods were applied for all risk models, i.e., relative risk projection up to <95 years of age, an exposure scenario of 2 WLM per year from age 18–64 years, and baseline mortality rates representing a mixed Euro-American-Asian population. Depending upon the choice of model, the estimated LEAR per WLM are 5.38 × 10−4 or 5.57 × 10−4 in the full PUMA cohort and 7.50 × 10−4 or 7.66 × 10−4 in the PUMA 1960 + sub-cohort, respectively. The LEAR per WLM estimates derived from risk models reported for previously published uranium miners studies range from 2.5 × 10−4 to 9.2 × 10−4. PUMA strengthens knowledge on the radon-related lung cancer LEAR, a useful way to translate models for policy purposes.

Evaluation of outdoor radon levels and its dependence on the radium content in soil in the environs of Belagavi India

The paper presents the seasonal variation of outdoor radon levels and the measured lung dose to the population of the Belagavi region of India. The outdoor radon levels were measured in different seasons using LR-115 (type II) films fixed in a pin-hole cup detector. The outdoor radon levels in this work were found to be high in summer with values ranging from 11.8 to 27.3 Bq m−3 with a mean value of 20.0 Bq m−3. Lower radon levels were observed in monsoon season and the values range from 3.8 to 15.8 Bq m−3, with a mean value of 10.0 Bq m−3. The potential alpha energy concentration was maximum in summer with a mean value of 3.3 mWLM. The mean annual exposure was found to be 1.4 mWLM and the mean annual inhalation dose was 0.2 mSv y−1. The activity of 226Ra in soils was measured using a NaI (Tl) detector based on gamma ray spectrometer. The 226Ra activity of the study area was in the range of 16.5 to 70.4 Bq kg−1 with a mean value of 32.4 Bq kg−1. The correlation coefficient between the radium content in soil and outdoor radon levels was studied. The present study shows a significant correlation of 0.7, between outdoor radon levels and the radium content in the soil.

Measuring societal attitudes and behaviours towards radon indoors: A case study of Slovenia

Public opinion surveys play a crucial role in assessing public awareness, knowledge, and radon risk perception in the context of national Radon Action Plans. However, many of these surveys are constructed without a solid foundation in behavioural theories, health protection theory, or social science methodology. This lack of foundation can lead to misguided priorities in radon mitigation interventions and ineffective communication strategies, ultimately resulting in low compliance with testing and mitigation in private homes. By developing and testing scales that measure a wide range of theory-based socio-psychological concepts influencing protective behaviour of individuals facing radon risk, this study provides researchers, authorities, and practitioners with a useful and versatile survey tool to explore the complexity of human behaviour in the context of radon. The results of this survey, conducted in Slovenia with a representative sample of respondents from low, middle, and high radon risk areas (N = 2012), offer a foundation for assessing gaps and strategies to increase testing and remediation of homes. The findings suggest that communication interventions need to be more precisely tailored to specific population groups and should go beyond enhancing awareness, knowledge and radon risk perception. Effective strategies should evoke emotions, share personal stories, highlight successful mitigation cases, and use personal testimonies from individuals affected by lung cancer. Moreover, incorporating positive social norms can inspire more individuals to engage in testing and mitigation measures. Assessing theory-driven socio-psychological concepts through a survey allows researchers and policymakers to craft more effective strategies aimed at promoting radon testing and mitigation, thereby enhancing overall public health.

Updated risk models for lung cancer due to radon exposure in the German Wismut cohort of uranium miners, 1946-2018.

UNSCEAR recently recommended that future research on the lung cancer risk at low radon exposures or exposure rates should focus on more contemporary uranium miners. For this purpose, risk models in the German Wismut cohort of uranium miners were updated extending the follow-up period by 5years to 1946-2018. The full cohort (n = 58,972) and specifically the 1960 + sub-cohort of miners first hired in 1960 or later (n = 26,764) were analyzed. The 1960 + sub-cohort is characterized by low protracted radon exposure of high quality of measurements. Internal Poisson regression was used to estimate the excess relative risk (ERR) for lung cancer per cumulative radon exposure in Working Level Months (WLM). Applying the BEIR VI exposure-age-concentration model, the ERR/100WLM was 2.50 (95% confidence interval (CI) 0.81; 4.18) and 6.92 (95% CI < 0; 16.59) among miners with attained age < 55years, time since exposure 5-14years, and annual exposure rates < 0.5WL in the full (n = 4329 lung cancer deaths) and in the 1960 + sub-cohort (n = 663 lung cancer deaths), respectively. Both ERR/WLM decreased with older attained ages, increasing time since exposure, and higher exposure rates. Findings of the 1960 + sub-cohort are in line with those from large pooled studies, and ERR/WLM are about two times higher than in the full Wismut cohort. Notably, 20-30years after closure of the Wismut mines in 1990, the estimated fraction of lung cancer deaths attributable to occupational radon exposure is still 26% in the full Wismut cohort and 19% in the 1960 + sub-cohort, respectively. This demonstrates the need for radiation protection against radon.

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.

Atmospheric in situ gamma-ray spectrometry for precipitation investigation

The underwater gamma-ray spectrometer GeoMAREA was utilized for in situ continuous monitoring of radon progenies in the atmosphere near the city of Anavyssos, Attica, Greece, during the period from 1 November 2017 until 1 April 2018. The acquired spectra before and during rainfalls were used to derive rainwater’s spectra revealing that the major contributors to the observed photo-peaks are the progenies of 222Rn (214Pb, 214Bi). The total counting rate of the spectra and the counting rate of the net areas of 352 keV and 609 keV photo-peaks (214Pb and 214Bi, respectively) proved to be effective parameters for rainfall identification and investigation. Statistical analysis did not reveal a significant association between radon progenies and temperature, pressure, humidity and dew point during rainfalls or dry meteorological conditions. However, preferable wind directions for rainwater rich in radon progenies revealed the impact of the atmospheric masses trajectories before a precipitation event. According to HYSPLIT modelling of selected rainfall events, air masses that pass over terrestrial areas at low altitudes (< 1500 m above ground level) 48 h before the event result in rainwater enriched in radon progenies. On contrary, air masses that pass before an event over terrestrial areas at higher altitudes (> 3000 m above ground level) result in rainwater of low radon progenies concentration. Overall, the method was considered promising for continuous in situ measurements of radon progenies in the atmosphere and may extend the use of radon as a tracer for studies related to climate investigation.