High Indoor Radon Concentrations Research Articles

Immune status of people living in the Tande-Tande sub-village (Indonesia), an area with high indoor radon concentration.

On Earth, there are significant variations in terms of exposure to naturally occurring radiation among different areas. Radon, a naturally-occurring radioactive gas that is the primary cause of lung cancer in nonsmokers and the second most prevalent cause among smokers, poses a considerable risk. Indoor radon, in particular, constitutes the most substantial source of natural radiation to which individuals are exposed. This study assessed the immune status of a population chronically exposed to high indoor radon concentration in Indonesia. Fifty-seven subjects from the Tande-Tande sub-village (high indoor radon concentration area) were compared to fifty-three participants living in the Topoyo village (low concentration area). We contrasted the immunological conditions of these two populations by measuring levels of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-4 (IL-4), and IL-10 in serum. Moreover, we also measured levels of the nuclear factor kappa B (NF-κB), superoxide dismutase (SOD), glutathione peroxidase (GPX), and protein kinase B in its phosphorylated (pAkt) and non-phosphorylated form (Akt) in peripheral blood mononuclear cells (PBMCs) of a subset of participants (31 from each population). TNF-α, IFN-γ, and IL-4 levels in Tande-Tande sub-village inhabitants were significantly lower than those in the control group living in the Topoyo village (p = 0.001, p = 0.017, and p = 0.002). The concentration of IL-10 also tended to be lower in people living in the high indoor radon concentration area, but it did not differ significantly between Tande-Tande sub-village inhabitants and Topoyo inhabitants (p = 0.106). Protein levels of NF-κB, pAkt, and Akt in Tande-Tande sub-village inhabitants also did not differ significantly between Tande-Tande sub-village inhabitants and Topoyo inhabitants (p = 0.234, p = 0.210, and p = 0.657). Similarly, activities of SOD and GPX did not differ significantly between the two populations (p = 0.569 and p = 0.949). Overall, despite their chronic exposure to high indoor radon concentrations, our study revealed no increase in the levels of TNF-α, IFN-γ, IL-10, IL-4, SOD, and GPX in the inhabitants of Tande-Tande sub-village compared with people living in the Topoyo village. Furthermore, our study demonstrated no activation in the Akt pathway, as indicated by the pAkt/Akt ratio observed in PBMC lysates of individuals residing in the Tande-Tande sub-village.

Characteristics of Indoor and Soil Gas Radon, and Discussion on High Radon Potential in Urumqi, Xinjiang, NW China

Urumqi City, located in the northwest of China, is a city with a high indoor radon concentration in a nationwide indoor radon survey in China. This study focuses on the assessment of the indoor radon level and its distribution in this city. Indoor radon measurement using RAD7 and solid nuclear track detector (SSNTD), soil gas radon measured by RAD7, and the determination of the specific activity of uranium and radium in soil samples by a high pure germanium spectrometer were performed from 2021 to 2023. The results reveal a wide range of indoor radon concentrations in Urumqi, with anomalies above 400 Bq/m3 in some dwellings. The arithmetical and geometric mean values of indoor radon concentration are 80 ± 77 Bq/m3 and 58 Bq/m3, respectively. The geometric mean value of radon measured by SSNTD is 101 Bq/m3. The distribution of areas with a high indoor radon concentration is spatially consistent with deep and large active faults or overlapping and intersection zones of multiple groups of faults. It is recommended to conduct a more comprehensive investigation and research into the elevated radon potential and radioactivity associated with building materials.

Indoor radon mitigation strategies: The Alto Minho region (Northern Portugal) practical case

The article explores techniques for mitigating indoor radon in buildings, including soil depressurization, anti-radon coatings and membranes, interior mechanical building pressurization, and natural and forced ventilation procedures. The effectiveness of each technique depends on various factors, such as indoor radon level or building construction type. The region of Alto Minho, Northern Portugal, mostly comprises single-family housing with different structures and materials, and performing an assessment stage is crucial for selecting the appropriate mitigation method. The ageing and declining population in the region suggests that the rehabilitation of existing buildings is more likely than the implementation of new construction. The article also emphasizes the potential impacts of soil depressurization and pressurization on soil geotechnical properties. Anti-radon barriers and mortars have been effectively used in high indoor radon concentration situations and can be combined with natural or forced ventilation procedures and real-time multi-parameter monitoring for improving indoor air quality and energy efficiency of buildings.

Public exposure in the Orenburg region due to natural sources of ionizing radiation. Part 2: Doses to the population of the eastern districts of the Orenburg region

The paper presents the estimated doses to the population of six eastern districts of the Orenburg region, Russia, based on the results of a comprehensive radiation survey conducted in 2019 in 34 settlements with previously found elevated levels of activity concentration of natural radionuclides in tap water from groundwater sources of drinking water supply. It is shown that the average individual annual effective dose due to all natural sources of ionizing radiation in 18 of 34 settlements corresponds to ‘elevated level’ of exposure due to natural sources according to established classification (from 5 to 10 mSv/year), and in another 7 settlements to ‘high level’ (over 10 mSv/year) with radon being the main contributor to the dose. Four settlements of Kvarkensky and Adamovsky districts, where the highest indoor radon concentrations had been found, were selected for a detailed survey, which included measurements of density of radon flux from the soil, radon concentration in soil gas, activity concentration of natural radionuclides in samples of building materials and in soil samples, and activity concentration of radon in tap water from groundwater sources of drinking water supply. Results of the detailed survey proved that the main source of radon in the buildings was the soil gas infiltration; compared to it, the contribution of waterborne radon release was insignificant.

Modeling and predicting mean indoor radon concentrations in Austria by generalized additive mixed models

Radon is a noble gas that occurs naturally as a decay product of uranium. Aside from smoking, radon is considered to be one of the major causes of lung cancer. Indoor environments, where radon can accumulate and potentially reach high concentrations, are of a particular concern. A mixed effects additive model along with a data-driven cross validation model selection method is applied to model the mean indoor radon concentration of dwellings in Austria. For this model a prediction approach is introduced, which enables the mapping of indoor radon potential to identify radon areas in Austria. The data used for modeling was collected in monitoring campaigns for private dwellings in Austria from 2013 to 2019. The proposed method allows policy makers to identify regions with high indoor radon concentrations and enables them to meet regulatory requirements or prioritize radon protection measures. The currently published Austrian radon map and the delineation of radon areas in Austria is based on this proposed method.

Rock-avalanche deposit causes extreme high indoor radon concentrations in Kinsarvik, Ullensvang municipality, Western Norway

The radon problem in Kinsarvik, Ullensvang municipality in Western Norway, is among the most severe in the world. Annual average indoor radon concentrations as high as 56,000 Bq/m3 have been measured. The problem affects >100 houses, where average yearly indoor radon concentrations of 4340 Bq/m3 has been reported. Indoor radon concentrations vary during the year, which has been explained by thermally induced flows of radon-bearing air through a porous ice-margin deposit.Updated geological knowledge and new mapping methods (LIDAR data) have allowed for a re-examination of the problem. There is significant evidence that does not fit with the established geological understanding that classifies the Kinsarvik deposit to be an ice-marginal moraine. Instead, the landforms and internal structures of the deposit are characteristic of a rock-avalanche deposit. The LIDAR data suggests a rockslide deposit of approximately 50 million m3.Airborne and ground gamma-ray spectroscopy show elevated uranium content in the granitic bedrock north and east of Kinsarvik. These uranium-bearing rocks are also found in an open pit in the Kinsarvik deposit.Terrestrial cosmogenic nuclide dating of four surface boulders shows an average age of 10,900 ± 600 years. This suggests the rock avalanche fell immediately after the last deglaciation of Western Norway.Our results support that the radon problem in Kinsarvik is caused by uranium bearing bedrock and a porous rock-avalanche deposit that emanates radon, which in turn exhibits an alternating, temperature driven flow direction.

Public exposure in the Orenburg region due to natural sources of ionizing radiation. Part 1: Results of the comprehensive survey of settlements in the eastern districts of the Orenburg region

The paper presents results of a comprehensive radiation survey conducted in 2019 in six districts of the eastern part of the Orenburg region in 37 settlements with previously found elevated levels of activity concentration of natural radionuclides in tap water from groundwater sources of drinking water supply. The survey included measurements of indoor radon concentrations and EEC in residential and public buildings, as well as measurements of ambient dose equivalent rate of gamma radiation indoors and outdoors. The survey revealed that annual average indoor radon EEC in many residential buildings in 23 settlements and public buildings in 25 settlements exceeded the hygienic norm (action level) of 200 Bq/m3 adopted in Russia for existing buildings. The highest values of annual average indoor radon EEC were obtained in residential buildings in Novovinnitskoe (1242 Bq/m3), Bratslavka (987 Bq/m3) and Anikhovka (942 Bq/m3) in Adamovsky district, and in public buildings in Kvarkeno (2291 Bq/m3) in Kvarkensky district, Karabutak (1114 Bq/m3) and Novovinnitskoe (923 Bq/m3) in Adamovsky district. The established hygienic norms in terms of ambient dose equivalent rate indoors and outdoors were not exceeded in the surveyed settlements. Results of the survey showed that the main reason for high indoor radon concentrations in residential and public buildings in the settlements of the eastern part of the Orenburg region is not related to the usage of tap water from groundwater sources of drinking water supply with elevated levels of activity concentration of natural radionuclides.

광주도시철도 지하역사 내 실내공기 및 지하수 중 라돈농도 분포연구

In this study, the radon concentration in the indoor and underground water of Gwangju subway stations were measured from December 2021 to September 2022 with long-term(more than 90 days) and short-term cycles(48hr). As the measurement places, platform, office, and pump room were selected. Ventilation time and underground water volume are main influencing factors for indoor radon concentration. As a result of study, the long-term radon concentration of indoor air was 17.3 ㏃/㎥ at the platform, 31.0 ㏃/㎥ at the office, and 112.1 ㏃/㎥ at the pump room. The radon concentration per hour in indoor air was measured using Rad-7 with short-term cycle(48 hours), the highest concentration was measured at 53.9 ㏃/㎥ at the platform, 88.9 ㏃/㎥ at the office, and the radon concentration in the office showed about 39% higher than that in the platform. The radon concentration of indoor air in the subway stations was affected by bedrock and depth. As a result of additional measurement for a week in the pump room with a high concentration of radon distribution, it was confirmed that the radon concentration decreased periodically at the operating time of the ventilation system and decreased by 86%. The three sites with a large amount of underground water showed high indoor radon concentration in order. There was a close correlations between the radon concentration of underground water in the subway station and the radon concentration in indoor air.

Indoor radon levels in apartments of Erbil city by using long and short term techniques

Inhalation of radon (222Rn) and daughter products are a major source of natural radiation exposure. Measurement of indoor radon concentrations were performed in the two hundred rooms for the 25 apartments in Erbil city by using long term technique (CR-39 SSNTDs) for 90 days exposure time and short term technique (radon monitor) for 2 hours exposure time. The higher value of average indoor radon concentration for long and short term techniques was found in Office rooms 56.72±14.72 Bq/m3 and 48.64±12.52 Bq/m3, respectively and lower value was found in Drawing rooms 42.11±10.82 Bq/m3 and 34.45±8.66 Bq/m3, respectively. The mean annual estimated effective dose was received by the residents of the studied area was 1.14 mSv. The highest indoor radon concentrations was found in ground floor for all apartment comport with the first, second and third floors. The rate indoor radon concentration in different type rooms depended of the ventilation rate and the age of the building.

Confined Spaces in Buildings with High Indoor Radon Concentration: A Case Study Analysis with the Application of Constructive Remediation Measures

Radon is an increasingly common concern, mainly when it is found indoors exposing the users of the space to radiation. As a gas, radon is an element produced due to uranium decay; it emanates naturally from soil and is considered by the World Health Organization as the second most common cause of lung cancer. Several methodologies are available for mitigating the indoor radon concentration, with distinct improvements and efficiencies that need to be proved with on-site testing. The case study here presented analyzes the effect of applying a barrier membrane, covering the pavement of a ground floor room located in a historic building with a high occupancy rate, on an abnormal radon concentration evidenced by experimental data. After the barrier membrane installation, a new long-term monitoring campaign (3 months) was carried out to assess indoor radon concentration. The obtained results showed that the barrier membrane lowered the indoor radon concentration by 90%. However, the radon exposure level remained higher than the recommended level to enable safe occupation and the regular use of space. Nevertheless, as the reduction in the radon concentration was very significant by the adoption of a barrier membrane, the combination of this technical solution with other mitigation methodologies, namely including the adoption of mechanical ventilation procedures, can become a very efficient solution for radon remediation, reducing the number of air changes per hour (ACH) from 30–60 to 4–6.

Residential Homes with Extremely High Indoor Radon Concentrations in Southern Lehigh County, Pennsylvania.

A housing development of 87 new homes on approximately 300 acres of former farm land was found to have 19 homes with basement radon-222 ( 222 Rn) concentrations greater than 37,000 Bq m -3 , with the highest recorded result to date being 648,000 +/- 1,031 Bq m -3 , based upon the diffusion barrier charcoal canister result. The US Environmental Protection Agency (EPA) Action Level for 222 Rn is 148 Bq m -3 . This single-family housing development is in the southeast corner of Lehigh County, Pennsylvania, about 58 km northwest of Philadelphia, in a geologic unit known as the Epler Formation. Radon testing in homes in this development began in the fall of 2014 and is now complete. Initial testing consisted of charcoal canisters mailed to homeowners. Subsequent testing in newly built homes consisted of testing prior to occupancy. This testing was quite extensive, with continuous radon monitors, passive radon monitors, and grab sampling for radon gas and progeny in the basement and on the first floor of each home as well as gamma surveys in the basement, on the first and second floors, and outside of each home. All but one of the new houses in this development had passive radon resistant features installed during the construction phase. In all cases, fans were added to the passive systems to make them active systems, which were needed to control these extremely high radon levels. Additional radon mitigation work such as adding additional suction points was also needed in several homes to reduce levels to below EPA guidelines. The unique geology and high 226 Ra soil concentrations in this specific area are the causes of these extremely high radon levels. Radon measurement data both inside these homes and in the outdoor ambient air, as well as 238 U and 222 Ra rock and soil concentrations, are presented.

Chromosome aberrations, micronucleus frequency, and catalase concentration in a population chronically exposed to high levels of radon

Purpose To deepen our knowledge on the effects of high levels of indoor radon exposure, we assessed the frequencies of unstable and stable chromosome aberrations and micronucleus (MN), as well as the concentration of an endogenous antioxidant (catalase, CAT), in blood samples of individuals chronically exposed to high indoor radon concentrations in Indonesia (Tande-Tande sub-village, Mamuju, West Sulawesi). Moreover, we also investigated the occurrence of a radio-adaptive response (RAR) in Tande-Tande sub-village inhabitants using the G2 MN assay. Materials and Methods The frequencies of dicentric (DC), acentric (AF), ring (R), and translocation (Tr) chromosomes in Tande-Tande inhabitants were compared to those in people living in a reference area with low levels of indoor radon levels (Topoyo village, Indonesia). The number of MN per 1000 binucleated cells (BNC) and CAT concentration per total protein was quantified and compared between groups. Lastly, we irradiated (2 Gy) phytohemagglutinin-stimulated samples in vitro and measured the frequency of MN to verify the occurrence of a RAR in Tande-Tande sub-village inhabitants. Results and Conclusion The frequencies of DC, AF, and Tr did not differ between Tande-Tande inhabitants and control subjects (p = 0.350, 0.521, 0.597). The frequency of MN in Tande-Tande inhabitants was significantly lower than that in the control group (p = 0.006). Similarly, CAT concentration in Tande-Tande inhabitants was also significantly lower than that in the control population (p < 0.001). Significant negative correlations were identified for MN number and CAT concentration versus indoor radon concentration, annual effective dose, or cumulative dose both within groups and when all data were analyzed together. Our findings indicate that, despite the high indoor radon levels, Tande-Tande inhabitants are not under oxidative stress, since this group had lower CAT concentration and MN frequency than those in the control group. The negative correlation between MN frequency and indoor radon concentration, annual effective dose, and cumulative dose suggests the occurrence of an RAR phenomenon in Tande-Tande sub-village inhabitants. This interpretation is also supported by the results of the G2 MN assay, which revealed lower MN frequencies after in vitro irradiation of samples from Tande-Tande sub-village inhabitants than those in samples from the control group (p = 0.0069, for cumulative MN frequency; p = 0.0146, for radiation-induced MN only).

DETAILED INDOOR RADON SURVEY IN DWELLINGS OF PROVISIONAL RADON-PRONE AREAS IN KOREA.

The objective of this study is to determine indoor radon concentrations for 11 counties in Korea, develop a detailed radon distribution map and compare the results by some factors influencing indoor radon levels. The radon survey was conducted for 7y in provisional radon-prone areas selected based on the previous national surveys. The total number of samples was >2.5% of the entire dwellings by each county. The annual average indoor radon concentration for the survey areas had a geometric mean of 94Bqm-3 with 6.6% of all sampled dwellings showing values exceeding 300Bqm-3. Some areas with relatively high indoor radon concentration were identified through a spatial distribution map. Seasonal variations were observed with commonly the highest concentration in winter, and house characteristics influencing indoor radon levels. This study can serve as a basis for developing national radon action plans and guide for additional regional radon surveys.

Rock-Avalanche Deposit Causes Extreme High Indoor Radon Concentrations in Kinsarvik, Ullensvang Municipality, Western Norway

Rock-Avalanche Deposit Causes Extreme High Indoor Radon Concentrations in Kinsarvik, Ullensvang Municipality, Western Norway

High Indoor Radon Concentration Observed in Yomitan-son,Okinawa Prefecture, Southwestern Part of Japan

High Indoor Radon Concentration Observed in Yomitan-son,Okinawa Prefecture, Southwestern Part of Japan

Superoxide dismutase and glutathione peroxidase activities in a population exposed to high indoor radon concentration: a preliminary report

The objective of this study was to assess the effect of radon exposure on the modulation of endogenous antioxidants in a population chronically exposed to high levels of radon indoors. To do so, we measured the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) in peripheral blood mononuclear cells (PBMCs) of people living in an area with high indoor radon concentration (Tande-Tande sub-village, Indonesia). The activities of SOD and GPX in Tande-Tande inhabitants were compared with those in subjects living in the Topoyo village (Indonesia), an area with low indoor radon levels. The activities of SOD and GPX in Tande-Tande sub-village inhabitants did not differ from those in people living in the Topoyo village (0.37 ± 0.021 versus 0.28 ± 0.018 U/mg protein and 8.46 ± 1.48 versus 8.34 ± 1.65 U/mg protein, p > .05). For both populations, there was a significant positive correlation between SOD and GPX activities (p < .001). No significant effects of gender, age, smoking habit, and body mass index on SOD and GPX activities were found for both groups. Although no significant modulation of SOD and GPX activities in PBMCs was detected, further studies should expand the sample size and also assess antioxidant levels in the serum. This study provides a first picture of endogenous antioxidant systems in Tande-Tande sub-village inhabitants, but a more comprehensive analysis, including the measurement of catalase (CAT) activity, might provide additional insight into the effects of chronic exposure to high indoor radon concentrations.

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.

Indoor exposure levels of radon in dwellings, schools, and offices in China from 2000 to 2020: A systematic review.

After decades of development, the indoor environment in China has changed. A systematic review was conducted from peer-reviewed scientific papers with field test data of indoor radon in China from 2000 to 2020 for three types of buildings. The mean concentrations of indoor radon for dwellings, school buildings, and office buildings are 54.6, 56.1, and 54.9Bq/m3 . The indoor radon concentration was related to seasons, climate regions, ventilation, decoration, and other factors such as soil and outdoor air. Colder seasons, especially in severe colder areas of China, newer decorated buildings, closed windows, and doors were all associated with higher indoor radon concentrations. Variables like climate region and ventilation showed statistical significance in the correlation analysis. Regarding the increasing trend of indoor radon concentration in China during the last two decades, further study of indoor radon is necessary especially for school buildings and office buildings, and will help access its environmental burden of disease in China more accurately.

General Overview of Radon Studies in Health Hazard Perspectives.

The adverse human health effects due to ionizing radiation are well known. Radon is the major source of background radiation among those that are of natural origin. It contributes about 55% of the natural radiation dose to humans. It is a colorless, odorless, and tasteless radioactive noble gas that comes from the natural radioactive decay series of uranium. Radon can be found everywhere in the atmosphere and become attached to aerosols in the air. The aerosols carrying radon and its progeny can be inhaled and deposited in different regions of the human respiratory tract. The deposited radioactive aerosols continue to decay and exposing the lung to ionizing radiation can destroy sensitive cells in the lung, causing a mutation that turns to be cancerous. Different countries and international and national organizations put their action levels to reduce radon lung cancer risk. The Environmental Protection Agency recommends 148 Bq/m3 as the action level. On the other hand, International Commission for Radiation Protection (ICRP) recommends 200 Bq/m3 as the action level. The main objective of this review is to focus on how radon is established as a health hazard, ways of radon detection and measurements, methods of reducing and controlling high indoor radon concentration, and what are the recommended international action levels of radon concentrations. It mainly focuses on the health perspective of radon studies because it is now a crucial and hot issue in the world. In most developing countries like our country Ethiopia, radon studies are not well investigated.

Study of the possibility of using radon potential maps for identification of areas with high indoor radon concentration

In this study, five different methods for determining the geogenic radon potential are compared in the Mochovce region, Slovakia. Based on these methods, maps of radon potential were made and localities with suspected elevated indoor radon levels were identified. Subsequently, indoor radon concentrations measurements were performed there. Based on the measurements in six municipalities, an approximately linear relationship was found between the values of geogenic radon potential and indoor radon concentrations. These results confirm the usability of radon potential maps as valuable tools for characterizing radon-prone areas.