Radon Concentration Research Articles

Radon indoors source potential from soil gas in a temperate climate: impact of infiltration rate and seismicity

Indoor radon source potential from unground soil was monitored using prototype devices approaching a dwelling with a cellar basement at 1 depth from the soil-atmosphere interface. Therefore, the radon concentrations in soil gas were monitored at 1 m depth. Integrated radon measurements were performed, and the results correlated with meteorological parameters. The influence of the difference in outdoor and device-soil temperature was considered, and the infiltration rate was calculated. The effect of the soil temperature gradient on the soil radon entry rate was evaluated. The indoor radon entry rate due to the soil gas was 7.0 ± 2.7 Bq m−3 h−1. The radon entry rate was 5.0 ± 0.8 Bq m−3 h−1 due to diffusion. In contrast, the advection-drive flow of soil gas is ranged up to ± 4.0 Bq m−3 h−1. So, the infiltration rate of the model dwelling was 0.7 (± 0.5) × 10−1 h−1 if only the stack effect occurred. The radon levels in tap water were measured, and the radon entry rate was estimated at 1.3 ± 0.7 Bq m−3 h−1. If the ventilation rate is low or seismic faulting appears, the soil radon entry is increased by one order of magnitude. The soil radon appeared like the building materials, having 1/3 of the total indoor radon entry, while outdoor air was slightly lower (28%), with tap water at 5%. The resident’s mortality risk occurred at < 2.5% for typical dwellings in temperate climate areas founded on sand-gravel underground. The risk rises to 34% with an extremely low ventilation rate between indoors and outdoors or high radon entry from the soil due to seismic faulting.

ANTIOXIDANTS, BIOCHEMICAL, AND HEMATOLOGICAL PARAMETERS CHANGE IN WORKERS OCCUPATIONALLY EXPOSED TO RADON INHALATION AT CERTAIN CONSTRUCTION MATERIAL INDUSTRIES IN ERBIL, IRAQ

This study examined the effects of radon on the endogenous antioxidants, biochemical, and hematological parameters of workers in Erbil, Iraqi Kurdistan. This was carried out to ascertain how radon affects the health of those who work in certain factories producing building materials. The case study group consisted of 70 workers, who were then divided into seven subgroups (gypsum, cement plant, lightweight block, marble, red brick 1, crushed stone, and concrete block 2), while the control group consisted of 20 healthy volunteers. The total antioxidant capacity (TAC), levels of carcinoembryonic antigen (CEA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), the complete blood count (CBC), and liver function tests were evaluated. The statistical analysis revealed that the antioxidant activities and CEA levels between the case study group and the control group differed significantly. Also, antioxidant enzyme activities and indoor radon concentration, the annual effective dosage, were found to be highly significantly correlated by Pearson and Spearman analyses in the case study group. Additionally, the results demonstrated a substantial correlation in the data between the levels of CEA biomarkers and radon (r=0.478, p˂0.000). The present results showed that radon concentration increased alanine aminotransferase (ALT) activity in a radon concentration-dependent manner (r=0.263 and p ˂0.05). The aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin activities, on the other hand, were not significantly affected by radon. The most significantly influenced CBC parameter was the low white blood cells (WBC) in the case study group compared to the controls. Low platelet count (PLT) was the second-highest problematic metric. The other CBC values, however, did not significantly differ between the research group and the control group. This study offers a preliminary image of the endogenous antioxidant systems in employees, especially to show a connection between radon and the occurrence of cancer among workers in Iraq Kurdistan Region.

Evaluating county-level lung cancer incidence from environmental radiation exposure, PM2.5, and other exposures with regression and machine learning models

Characterizing the interplay between exposures shaping the human exposome is vital for uncovering the etiology of complex diseases. For example, cancer risk is modified by a range of multifactorial external environmental exposures. Environmental, socioeconomic, and lifestyle factors all shape lung cancer risk. However, epidemiological studies of radon aimed at identifying populations at high risk for lung cancer often fail to consider multiple exposures simultaneously. For example, moderating factors, such as PM2.5, may affect the transport of radon progeny to lung tissue. This ecological analysis leveraged a population-level dataset from the National Cancer Institute’s Surveillance, Epidemiology, and End-Results data (2013–17) to simultaneously investigate the effect of multiple sources of low-dose radiation (gross γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma$$\\end{document} activity and indoor radon) and PM2.5 on lung cancer incidence rates in the USA. County-level factors (environmental, sociodemographic, lifestyle) were controlled for, and Poisson regression and random forest models were used to assess the association between radon exposure and lung and bronchus cancer incidence rates. Tree-based machine learning (ML) method perform better than traditional regression: Poisson regression: 6.29/7.13 (mean absolute percentage error, MAPE), 12.70/12.77 (root mean square error, RMSE); Poisson random forest regression: 1.22/1.16 (MAPE), 8.01/8.15 (RMSE). The effect of PM2.5 increased with the concentration of environmental radon, thereby confirming findings from previous studies that investigated the possible synergistic effect of radon and PM2.5 on health outcomes. In summary, the results demonstrated (1) a need to consider multiple environmental exposures when assessing radon exposure’s association with lung cancer risk, thereby highlighting (1) the importance of an exposomics framework and (2) that employing ML models may capture the complex interplay between environmental exposures and health, as in the case of indoor radon exposure and lung cancer incidence.Graphical abstract

Study of the delayed pumping effect in the underground laboratory by the method of correlation analysis of radon and aeroion concentrations

Measurements and correlation analysis of radon and aeroion concentrations in the underground laboratory were carried out. For pairs of variables “pressure — radon” and “pressure — ions”, a delayed pumping effect was found, similar to that previously observed for neutrons and gamma quanta. A simple phenomenological model explaining the results is presented. In this model, the reason for the delay is the gradual accumulation of radon in the room with a decrease in atmospheric pressure. The balance of the radon accumulation rate, the time of its radioactive decay and the characteristic time of pressure variations leads to an effective delay of 2 days between atmospheric pressure variations and radon concentration. Correlation analysis for the variables “pressure — ions” indicates that ions formed in the pores of the soil are already present in the air carrying radon to the laboratory. These ions make up approximately 21% of the total number of ions in the laboratory.

Comparative study of the radon and thoron concentrations in the indoor environment of the Budhakedar region of the Garhwal Himalaya, India

Comparative study of the radon and thoron concentrations in the indoor environment of the Budhakedar region of the Garhwal Himalaya, India

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.

Automatic tracking of the energy spectrum areas of Po-218 and Po-214 at various temperatures

Radon and its decay products emit internal radiation in the respiratory system upon inhalation, which is a significant contributor to the development of lung cancer in humans. Accurate measurement of radon concentration is undoubtedly very important. Among the commonly used radon measurement methods, the electrostatic collection method stands out. This method involves counting the energy spectrum peaks of alpha particles, generated by the decay of radon daughters Po-218 and Po-214, which are collected on the surface of a semiconductor detector to determine radon concentration. According to experimental findings, measurements at different ambient temperatures cause Po-218 and Po-214 to peak drift. This drift adversely affects the accuracy of radon measurement using traditional methods. This study focuses on the characteristics of α-energy spectra from Po-218 and Po-214. It calculates the peak heights for all α-energy spectra and identifies the two peaks with the highest heights. Subsequently, an algorithm is developed to automatically track the peak positions of Po-218 and Po-214, accurately locating their counting intervals. The results demonstrate that the algorithm successfully achieves the desired outcomes through experiments conducted at different temperatures and measurement durations, thus validating its effectiveness. This method holds significant practical value in ensuring the accuracy of radon measurement.

РАДИОЭКОЛОГИЧЕСКАЯ ОБСТАНОВКА В РАЙОНЕ ПЛОЩАДКИ УРАНОВОГО НАСЛЕДИЯ – ШАХТА «СТЕПНАЯ» (КАЛМЫКИЯ)

Purpose: To study the radio-ecological situation on the “uranium legacy” site of the former Stepnaya mine in the Republic of Kalmykia. Material and methods: To measure the ambient dose equivalent rate (ADER), the pedestrian gamma survey method was used using a portable spectrometric complex MKC-01A Multirad-M and dosimeter-radiometer MKC-AT6101c. The activity of gamma-emitting radionuclides in soil samples was measured using a stationary gamma spectrometer from CANBERRA. The activities of 210Po and 210Pb were measured using a radiometric installation UMF-2000 following their radiochemical separation from samples. Short-term measurements of activity concentration (AC) and equivalent equilibrium activity concentration (EEAC) of radon were carried out with an aerosol alpha radiometer for radon and thoron RAA-20P2 Poisk. Doses of radiation exposure to biological objects were estimated using dose coefficients provided by ICRP Publication 136 taking into account recommendations R52.18.820-2015. Results: Gamma ADER values at the mine site vary over the range from 0.1 to 0.36 µSv/h, and on 80 % of the area these values do not exceed the background value of 0.14 µSv/h. Along the road from the mine to Narta village the ADER values do not exceed background values with exception of the area around the dam, where in a local part of this area of about 300 m2 these values reach 0.49 µSv/h. The specific activities of natural radionuclides in the soil are below the criteria for classification as solid radioactive waste (SRW). Under the certain weather conditions, radon EEAC inside the buildings on the site reaches 13 kBq/m3, and on the territory 1-1.5 kBq/m3. Ecological risk for the terrestrial biological objects under consideration (grass, soil worm, snake and mouse-like rodents) does not exceed 0.025. Conclusions: The radiation situation at the Stepnaya mine site meets the requirements of SP LKP-91, which were in force until 2020. However, in order to transfer the facility to a local government body, reclamation work should be carried out in accordance with the Federal Law “On the Transfer of Lands or Land Plots from One Category to Another” dated December 21, 2004 No. 172-FZ and GOST R 59057— 2020 «Environmental Protection. Lands. General Requirements for Reclamation of Affected Lands». Doses of exposure to biological objects do not impact significantly on morbidity, reproduction and life expectancy of terrestrial biological objects.

Study of the Delayed Pumping Effect in an Underground Laboratory by Correlation Analysis of Radon and Air Ion Concentrations

Study of the Delayed Pumping Effect in an Underground Laboratory by Correlation Analysis of Radon and Air Ion Concentrations

Investigating and Measuring Radon Gas Concentration in Tehran and Alborz Metro Stations

Abstract Humans are regularly exposed to various types of radioactive radiation and, of course, to Radon-222 over the course of their lives. According to the report of the United Nations scientific committee on the effects of atomic radiation in 2000, the average human is estimated to be exposed to about 4.2 mSv of radioactive radiation each year, 52% of which is caused by inhalation of radon gas. The radon gas is one of the most important elements that is emitted from the decay of natural uranium and radium in the earth. Therefore, the concentration of this gas can be higher in enclosed spaces, especially underground locations, and it is important to measure the amount of radon gas radiation in these underground stations. In this research, a domestically manufactured environmental meter for radon gas was used to measure the concentration of this gas in different Tehran metro stations. In general, all 42 subway stations of Tehran and Karaj cities were measured at continuous time intervals during the spring season. On average, trace amounts of radon gas were observed in all the stations, but high concentrations of radon gas were measured at some stations, such as Tajrish and Ghaem stations in the northern Tehran-Karaj plain due to underground water resources, fault type and distinct geological structures. According to the US Environmental Protection Agency (EPA) standard, the maximum permissible amount of radon gas concentration in the air is 148 Bq/m3, while the average amount was 156 Bq/m3 at Tajrish station. This amount is above the permissible limit and can therefore be considered hazardous to health. Geologically, the Meydan-e-Azadi (Azadi square) station on line 4 located in the center of Tehran also revealed a near high radon concentration due to bedrock that it mainly has been consisted of calcite. Consequently, measures for better ventilation and easier air movement are required in such stations.

P450 Influence of radon levels at home in the clinical course of inflammatory bowel disease incident 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 evolution of the disease. The aim of this study is to analyze if residential radon exposure is associated with the evolution and development of flares or hospitalizations of IBD new diagnosed patients in a radon-prone area. Methods An observational prospective study was developed between June 2020 and September 2023, including incident cases with IBD that had been 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. All patients were followed-up through one year to assess the evolution of the disease. Hospitalizations related with the disease during the period, and number and severity of flares (measured by Partial Mayo Score and Harvey- Bradshaw) were collected. Radon levels were measured over three months in the participants’ home. 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. 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 136 patients with IBD (78 ulcerative colitis, 52 Crohn’s disease and 6 unclassified colitis) were included and prospectively followed, with a median age of 52 years old (IQR 40 – 59). 50% were females. There were no statistically significant differences in radon levels, taking levels of 0-99 Bq/m3 as reference, between patients hospitalized compared with non-hospitalized (OR 0.8 95%CI 0.3-2.1 for 100-299 Bq/m3, OR 1.7 95%CI 0.6-5.0 for &amp;gt;299 Bq/m3) nor in patients with a flare compared with patients without flares during the follow-up year (OR 0.4 95%CI 0.0-4.5 for 100-299 Bq/m3, OR 5.4 95%CI 0.8-34.3 for &amp;gt;299 Bq/m3). Radon levels were not associated with the number of flares either (OR 0.6 95%CI 0.3-1.7 for 100-299 Bq/m3, OR 1.5 95%CI 0.5-4.5 for &amp;gt;299 Bq/m3). Results are shown in table 1. Stratifying by type of IBD, results do not vary. For Crohn’s disease, OR for flare are 2.5 (95%CI 0.4-16.1) and 4.1 (95%CI 0.6-27.9), and for hospitalization 1 and 6.5 (OR95% (0.2-205-2). For ulcerative colitis, OR for flare are 0.6 (95%CI 0.2-1.8) and 1.8 (95%CI 0.4-7.8) and for hospitalization 0.9 (95%CI 0.1-17.1) and 9.3 (95%CI 0.6-134.0). Conclusion Indoor radon concentration seems to be not associated with an initial worst evolution of IBD patients in terms of hospitalizations or flares.

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.

Radon Exposure, Clonal Hematopoiesis, and Stroke Susceptibility in the Women's Health Initiative.

Studies suggest that clonal hematopoiesis of indeterminate potential (CHIP) may increase risk of hematologic malignancy and cardiovascular disease, including stroke. However, few studies have investigated plausible environmental risk factors for CHIP such as radon, despite the climate-related increases in and documented infrequency of testing for this common indoor air pollutant.The purpose of this study was to estimate the risk of CHIP related to radon, an established environmental mutagen. We linked geocoded addresses of 10,799 Women's Health Initiative Trans-Omics for Precision Medicine (WHI TOPMed) participants to US Environmental Protection Agency-predicted, county-level, indoor average screening radon concentrations, categorized as follows: Zone 1 (>4 pCi/L), Zone 2 (2-4 pCi/L), and Zone 3 (<2 pCi/L). We defined CHIP as the presence of one or more leukemogenic driver mutations with variant allele frequency >0.02. We identified prevalent and incident ischemic and hemorrhagic strokes; subtyped ischemic stroke using Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria; and then estimated radon-related risk of CHIP as an odds ratio (OR) and 95% CI using multivariable-adjusted, design-weighted logistic regression stratified by age, race/ethnicity, smoking status, and stroke type/subtype. The percentages of participants with CHIP in Zones 1, 2, and 3 were 9.0%, 8.4%, and 7.7%, respectively (ptrend = 0.06). Among participants with ischemic stroke, Zones 2 and 1 were associated with higher estimated risks of CHIP relative to Zone 3: 1.39 (1.15-1.68) and 1.46 (1.15-1.87), but not among participants with hemorrhagic stroke: 0.98 (0.68-1.40) and 1.03 (0.70-1.52), or without stroke: 1.04 (0.74-1.46) and 0.95 (0.63-1.42), respectively (pinteraction = 0.03). Corresponding estimates were particularly high among TOAST-subtyped cardioembolism: 1.78 (1.30-2.47) and 1.88 (1.31-2.72), or other ischemic etiologies: 1.37 (1.06-1.78) and 1.50 (1.11-2.04), but not small vessel occlusion: 1.05 (0.74-1.49) and 1.00 (0.68-1.47), respectively (pinteraction = 0.10). Observed patterns of association among strata were insensitive to attrition weighting, ancestry adjustment, prevalent stroke exclusion, separate analysis of DNMT3A driver mutations, and substitution with 3 alternative estimates of radon exposure. The robust elevation of radon-related risk of CHIP among postmenopausal women who develop incident cardioembolic stroke is consistent with a potential role of somatic genomic mutation in this societally burdensome form of cerebrovascular disease, although the mechanism has yet to be confirmed.

An Evaluation of Radon Concentrations in Arin Lake, Bitlis

Arin Lake, situated in the Bitlis province, is a soda lake that holds significant ecological importance as a habitat for migratory bird species such as flamingos and white-headed ducks. In order to investigate the potential radiation exposure to the environment and living organisms in the area, radon concentration levels and dose calculations were determined for water samples collected from 27 different points in Arin Lake. The radon levels were determined using the AlphaGUARD PQ2000 PRO radon monitoring system, which has the range of 2–2.106 Bqm−3. The results of the radon concentration measurements are between 0.06 and 0.39 Bq/L, with a mean of value of 0.17 Bq/L. The annual effective doses for ingestion (Deff-ing) and inhalation (Deff-inh) were calculated at values ranging from 0.14 to 0.99 µSv/year. The radon levels were found to be lower than international standard values. Furthermore, the outcomes of this research were subjected to comparison with other studies in the literature.

Simultaneous measurements of radon, thoron and thoron progeny and induced cancer risk assessment in Djeno, Pointe-Noire, Republic of Congo.

In this study, the activity concentrations of radon (222Rn), thoron (220Rn) and thoron progeny were measured simultaneously in Djeno (Pointe-Noire, Republic of Congo) using RADUET detectors to evaluate the air quality and the radiological risks due to the inhalation of these radionuclides. Activity concentrations of radon progeny were calculated from those of radon. Indoor radon, thoron and progenies followed a lognormal distribution ranging between 20 and 40, 6 and 62, 8 and 17.6 and 0.4 and 19.6Bqm-3 for radon, thoron, radon progeny and thoron progeny, respectively. Mean values for radon were lower than the worldwide values estimated by the United Nation Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), which are 40Bqm-3 (arithmetic mean) and 45Bqm-3 (geometric mean). Radon concentrations in the dwellings under study were below the World Health Organization and the International Commission on Radiological Protection recommended reference levels, which are, respectively, 100 and 300Bqm-3. The mean concentration of thoron was twice the world average value of 10Bqm-3 estimated by UNSCEAR. Thoron progeny mean concentration was sharply greater than the typical value (0.3Bqm-3) for indoor atmosphere provided by UNSCEAR. Annual effective dose ranges were 0.40-0.87mSv (arithmetic mean, 0.57±0.11mSv) for radon and 0.10-4.14mSv (arithmetic mean, 0.55±0.77mSv) for thoron. The mean value for radon was lower than the value (1.15mSv) estimated by UNSCEAR, while the mean value for thoron was five times higher than the UNSCEAR value (0.10mSv). The study showed that the use of the typical equilibrium factor value given by UNSCEAR to compute effective dose led to an error above 80%. Finally, the results of this study showed that the excess relative risk of radon-induced cancer was low, below 2% for the population under 55y. The results presented in the present study prove that the population of Djeno is exposed to a relatively low potential risk of radon- and thoron-induced cancer.

Radon levels and dose assessment at the basement workplaces of hospitals in different regions of Taiwan

The basements of large hospitals in Taiwan are usually working areas for image radiometry, radiation therapy, and nuclear medicine, where the radon concentration can be accumulated. This study investigated radon concentrations in the basement working environments of 30 hospitals in different regions with various geology of Taiwan, aiming to explore the relationship between geological conditions and radon concentrations and estimate the radiation dose received by the working staff. Portable MR107+ semiconductor radon detectors calibrated with a radon chamber were used for radon measurement at the hospital basement working areas according to the protocol of MAH-2019 instrument placement recommendations from the US EPA. The excess lung cancer risk (ELCR) as well as the lung cancer cases per million persons (LCC) were further derived from the radiation dose.The basement working areas investigated are located on the first to sixth underground floors of hospitals in Taiwan mainland and islands, Penghu and Kinmen. The 222Rn concentration higher than 100 Bq/m3 was observed at CH-1 (122.1 Bq/m3) in Changhua City and CY-1 (114.7 Bq/m3) in Chiayi City. This is attributed to that the central air conditioning systems of these hospitals were turned off during off-duty hours. The radon concentrations of all hospitals were lower than the action level, 150 Bq/m3, regulated by the US EPA. No significant relationship was found between radon concentration and the geological characteristics of the measured sites. That is, the ventilation of the basement working areas in hospitals is more important than local geological characteristics on indoor radon concentration, and therefore proper ventilation is crucial for reducing radon gas concentration in the hospital basements. Estimated annual effective dose from 222Rn for the hospital staff was higher than 1 mSv/y at YL (1.24 mSv/y), CH-1 (1.64 mSv/y), CY-1 (1.54 mSv/y), CY-2 (1.34 mSv/y), and PH-2 (1.14 mSv/y), and that for the rest sites was <1 mSv/y. The maximum mean ELCR was found to be 0.63% at CH-1, and the related LCC was estimated to be 29.5 per million persons.

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.

Investigating Radon Concentration in Groundwater and Seawater in the Eastern Coast of India

Investigating Radon Concentration in Groundwater and Seawater in the Eastern Coast of India

Simulation of excess lifetime cancer risk due to the presence of radon in groundwater in Wamba town of Wamba local government area, Nasarawa state, Nigeria

The measurements of Radon concentration in ten groundwater (4-wells and 6-boreholes) from Wamba town of Wamba Local Government Area of Nigeria had been carried out. The annual effective dose (AED) and the Excess Lifetime Cancer Risk (ELCR) due to ingestion of the groundwater was established to ascertain the risk outcome from the samples. Radon concentration was detected using RAD7. The minimum Radon concentration was 0.146 Bql-1 while the maximum was 0.474 Bql-1 with mean average of 0.3134 Bql-1 which are within the United States Environmental Protection Agencies (USEPA) 11.1 Bq/L recommendation. Moreso, the maximum and minimum Annual Effective Dose (AEDing) was 3.5×10^(-6) and 1.10×10^(-6) Sv/yr which are also within the 0.1 mSv/yr World Health Organization (WHO) recommendation, while the maximum and minimum Excess Lifetime Cancer Risk (ELCR) was 1.44×10^(-5) and 4.50×10^(-6) respectively. Cumulative probability simulation of the Excess Lifetime Cancer Risk (ELCR) was carried out using Oracle Crystal Ball software validated by 10 and 90% percentiles. Comparison of all the results with the European Union (EU)/World Health Organization (WHO) value of 500 Bq/L recommendation revealed that all the samples analyzed have Radon concentration below the recommended limit. The average mean Radon concentration in the ten locations from Wamba Town are within the recommended levels as confirmed by the simulation results. At 10% Probability, the highest risk was found in Event center (1.26×10^(-5)) while the lowest was found in the water sample collected from Angwan dalatu (1.05×10^(-6)) while at 90% probability the highest (1.62×10^(-5)) and lowest (1.37×10^(-6)) risk was found in the same Events center and Angwan dalatu. Though there is variation in the results based on locations which means that the concentration of Radon gas depends on the geological nature of the bedrock and generally increases with the uranium concentration in the local geology. The Excess Lifetime Cancer Risk (ELCR) dose results are far lower than the UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiations) recommended maximum contamination level of 0.003875. Therefore, no indication of any likelihood of cancer incidence as a result of waterborne radon within the studied community that may demand urgent intervention from radiological point of view.

Evaluation of radon concentrations in drinking water available in Baghdad Governorate markets, Iraq

Radon dust was measured in 15 samples Results: The mass of radon in potable water from Baghdad Governorate markets ranged from 3.5 (Bq/m3) to 74 (Bq/m3) with a mean value of 26.6 ±25.311 (Bq/m3). illustrated The annual effective dose (Ed) results for each group (3 months, 10 years, 15 years, and adults). The Ed values for the 3-month age group range from 0.10 to 0.88 μSv/year. as seen for the 10-year age group they range from 0.02 to 0.96 μSv/year; as seen for the 15-year age group they range from 0.13 to 0.98 μSv/year and as seen for the adult age group they range from 0.07 to 0.92 μSv/year Results indicated that the content of radon- 222 in healthy drinking water in Baghdad's market was within permissible limits set by the World Health Organization in 2008 and United Nations Scientific Committee on the Effects of Atomic Radiation in 2000. The annual effective dose of drinking water for infants in Baghdad's market is also within these limits.