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A comprehensive evaluation of the results obtained according to the measurement of radon gas in buildings and concrete, which is the most consumed material in the world after water, in accessible studies carried out in the last 40 years is the main objective of this study. The paper additionally aims to address the gap in the literature by comparatively determining which parameters affect radon–concrete and radon–building relationships. The scientific knowledge compiled within the scope of this article was presented under the main headings of radon and radon gas measurements in concrete and buildings. Radon gas, also known as the "invisible killer", is considered the second most important cause of lung cancer after smoking (the gas is responsible for 3–14% of lung cancer cases in the world). The results determined that radon concentration limits have been applied in the range of 100–400 Bqm−3 in houses and 100–3700 Bqm−3 in workplaces. Studies conducted on the exhalation rate of radon showed that the radon exhalation rate of concrete may be in the range of 0.23–510 Bqm−2 h−1. The results of indoor radon concentration measurements revealed that values between 4.6 Bqm−3 and 583 Bqm−3 were obtained. Despite the existing literature, some researchers state that there is an urgent need for an improved and widely accepted protocol based on reliable measurement techniques to standardize measurements of the radon exhalation rate of construction materials and the indoor radon concentration of buildings. [ABSTRACT FROM AUTHOR]

Although radon concentrations in outdoor environments are generally low, the indoor concentrations can become appreciably high thereby affecting the indoor air quality and causing some severe health challenges. Thirty (30) offices from the ground floor and first floor of some buildings within Ibrahim Badamasi Babangida (IBB) University campus, Lapai Nigeria, were randomly selected for indoor radon concentration (CRn) measurement using RAD7 continuous radon monitor. Annual effective dose was also computed to determine the level of public exposure. The results showed that radon concentration values for all the offices on the ground floor ranged between 9.6±2.7 Bqm-3 and 90.7±8.1 Bqm-3, with mean value of 28.5±4.8 Bqm-3 while the range of radon concentration at first floor was 2.5±1.4 Bqm-3 - 80.4±7.5 Bqm-3. All the measured indoor radon concentration levels were less than the 100 Bqm-3 action level proposed by World Health Organization (WHO). Average annual absorbed dose for both ground and first floors were 0.36±0.06 mSvy-1 and 0.24±0.05 mSvy-1 respectively, with corresponding mean annual effective dose of 0.86±0.15 mSvy-1 and 0.58±0.11 mSvy-1 in sequence. These values were below the 1.0 mSvy-1 safety limit set for public. Although the results did not suggest any immediate exposure threat to the public, it is important that the University staffs are adequately informed of indoor radon levels and its attendant health hazards. Improved and adequate ventilation of all the office buildings is highly encouraged in order to keep the radon levels as low as reasonably achievable (ALARA). [ABSTRACT FROM AUTHOR]

A comprehensive evaluation of the results obtained according to the measurement of radon gas in buildings and concrete, which is the most consumed material in the world after water, in accessible studies carried out in the last 40 years is the main objective of this study. The paper additionally aims to address the gap in the literature by comparatively determining which parameters affect radon–concrete and radon–building relationships. The scientific knowledge compiled within the scope of this article was presented under the main headings of radon and radon gas measurements in concrete and buildings. Radon gas, also known as the “invisible killer”, is considered the second most important cause of lung cancer after smoking (the gas is responsible for 3–14% of lung cancer cases in the world). The results determined that radon concentration limits have been applied in the range of 100–400 Bqm−3 in houses and 100–3700 Bqm−3 in workplaces. Studies conducted on the exhalation rate of radon showed that the radon exhalation rate of concrete may be in the range of 0.23–510 Bqm−2 h−1. The results of indoor radon concentration measurements revealed that values between 4.6 Bqm−3 and 583 Bqm−3 were obtained. Despite the existing literature, some researchers state that there is an urgent need for an improved and widely accepted protocol based on reliable measurement techniques to standardize measurements of the radon exhalation rate of construction materials and the indoor radon concentration of buildings.

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. [ABSTRACT FROM AUTHOR]

Objective: To explore the level of indoor radon concentration especially after recent 3 decades’ great economic development in metropolis Beijing, so as to describe the outline of indoor radon level in Beijing. Methods: A one-year integrated measurement on 800 dwellings was carried out from September 2018 to August 2019. Passive integrated radon cup monitor with CR-39 as an alpha-track detector was adopted for the survey. As a pilot study, measurement scheme was designed in detail. For measurement quality control, the background track density of CR-39 was strictly defined and controlled throughout the operation of the survey. Results: The annual geometric and arithmetic mean of radon concentration of the surveyed are (39.3 ​± ​12.9) and (42.0 ​± ​13.7) Bq/m3, respectively, varying from (12.1 ​± ​2.5) to (119.0 ​± ​7.8) Bq/m3. Radon concentration of the ground floor dwellings is obviously higher than that of other floors. No difference of radon level is found among the dwellings of other floors. Higher radon concentration in buildings built after 2010 is obtained compared with buildings built in 1980s, 1990s, and 2000s. Conclusions: There is no big change of radon concentration level in dwellings in Beijing area observed in general compared with a previous survey performed more than ten years ago. For high-rise buildings, building materials are suggested to be the main source of indoor radon. For higher radon concentration in buildings built in latest ten years, the change on building materials and indoor ventilation rate are thought to be the causes, further study in detail is needed to clarify.

In this study, the indoor radon concentrations map, starting from a sparse measurements survey, was realized with the Gini index method. This method was applied on a real dataset coming from indoor radon measurements carried out in Kpong, Ghana. The Gini coefficient variogram is shown to be a good estimator of the inhomogeneity degree of radon concentration because it allows for better constraining of the critical distance below which the radon geological source can be considered as uniform. The indoor radon measurements were performed in 96 dwellings in Kpong, Ghana. The data showed that 84% of the residences monitored had radon levels below 100 Bqm−3, versus 16% having levels above the World Health Organization's (WHO) suggested reference range (100 Bqm−3). The survey indicated that the average indoor radon concentration (IRC) was 55 ± 36 Bqm−3. The concentrations range from 4–176 Bqm−3. The mean value 55 Bqm−3 is 38% higher than the world's average IRC of 40 Bqm−3 (UNSCEAR, 1993). [ABSTRACT FROM AUTHOR]

This paper reviews the changes in indoor radon concentrations, measured in a university building in Gyeongju, Rep. of Korea, to find the relationship, it exists, between the indoor radon concentrations and the seismic activities in the area neighboring Gyeongju. The measurement period was from June 1, 2017, to May 31, 2019. During this period, numerous seismic activities occurred in the southeastern region of the Korean peninsula. Considering the magnitude and distances from our measurement place to epicenters, 11 earthquakes for analysis were chosen. Among these, nine earthquakes were found to have radon anomalies before their occurrences. Three earthquakes with a magnitude greater than 4.0 were scrutinized for the correlation between radon anomalies. Effects of the environmental variables such as relative humidity, barometric pressure, rainfall, and inlet temperature were also examined. Similar to those found in our previous study, spike-like patterns were also found in the indoor radon concentration distributions before the earthquakes. [ABSTRACT FROM AUTHOR]

The indoor radon concentrations in Kirklareli, Turkey were measured in living rooms of 19 houses during winter in 2019 using Airthings 222 Corentium Home Radon Gas Detector. The short-term and long-term measurements were performed in 1 and 7 days for each house to investigate radioactive radon gas exposure in Kirklareli buildings. The indoor radon concentrations were varied from 23 to 156 Bq m-3 for 1 day period and were varied from 16 to 77 Bq m-3 for 7 days period. The average radon gas concentration was found as 43.5 Bq m-3 and this result is higher than the average of Turkey and the world average. The annual effective doses due to radon gas exposure were also estimated. The annual effective dose rate ranged from 0.61 to 2.94 mSv y-1 with a mean value of 1.09 mSv y-1. [ABSTRACT FROM AUTHOR]

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.

In this study, the indoor radon concentrations map, starting from a sparse measurements survey, was realized with the Gini index method. This method was applied on a real dataset coming from indoor radon measurements carried out in Kpong, Ghana. The Gini coefficient variogram is shown to be a good estimator of the inhomogeneity degree of radon concentration because it allows for better constraining of the critical distance below which the radon geological source can be considered as uniform. The indoor radon measurements were performed in 96 dwellings in Kpong, Ghana. The data showed that 84% of the residences monitored had radon levels below 100 Bqm−3, versus 16% having levels above the World Health Organization’s (WHO) suggested reference range (100 Bqm−3). The survey indicated that the average indoor radon concentration (IRC) was 55 ± 36 Bqm−3. The concentrations range from 4–176 Bqm−3. The mean value 55 Bqm−3 is 38% higher than the world’s average IRC of 40 Bqm−3 (UNSCEAR, 1993).

It is commonly known that people are exposed to radon and its progenies since they spend about 35% of daytime at workplaces. This exposure has been reported to be more than 50% of the natural radiation. Therefore, determination of indoor radon concentration has been widely conducted by the scientists. This work presents indoor radon measurements and the associated annual dose equivalentsobtained in 28 public buildings of the Afyonkarahisar province. The survey was conducted using passive nuclear track detectors and repeated quarterly during a year.The investigation focused on the seasonal and regional effects in indoor radon concentration anomalies. The measured values ranged from 13 Bq.m-3to 1932 Bq.m-3, whereas the calculated average values were in the range of 21,75 Bq.m-3and 1032,50Bq.m-3. Moreover, the mean indoor radon concentration and the corresponding annual dose equivalent valueswere obtained as 158,83±13,16Bq.m-3and 1,25±0,10mSv.y-1, respectively.

Radon gas is the main natural source of exposure of the population to ionizing rays. Because of its impact on the health, this radioactive gas has become a great concern worldwide. In this study, radon concentrations in the air of some dwellings in Yopougon, one of the commune with the highest population rate of the district of Abidjan (Côte d’Ivoire), are reported using Solid State Nuclear Tracks Detectors (SSNTD) LR 115 type 2. The concentration values found vary from 26.3 to 173.3 Bq.m−3 with an average of 93.04 Bq.m−3. This mean value is inferior to the world minimum level (100 Bq.m−3). The corresponding annual effective doses obtained vary from 0.66 to 4.37 mSv.y−1. The mean value calculated which is 2.35 mSv.y−1 is higher than the action level (1 mSv.y−1) prescribed by ICRP 103, and also to the limits recommended by the WHO and the International Research on Cancer Center (IRCC). In this view, the Excess lung Cancer Risk (ECR) for the population living in the commune of Yopougon is evaluated. The values of ECR found associated to the average radon concentration are between 46 and 204 according to EPA and UNSCEAR standards.

This paper presents an analysis of indoor radon measurements carried out in municipality of Zubin Potok, northwestern part of Kosovo and Metohija. Annual measurements in two rooms of each house were performed by solid state nuclear track detectors commercially known as Gammadata. Average indoor radon concentration in different type of houses varied from 29-326 Bq/m3. A different year of house's construction including various types of building materials were selected for survey. A detail analysis showed that the differences in radon concentration occur between various building materials used for construction, flooring level, type of room and behavior of inhabitants. It was found that building materials in some houses contribute additionally to indoor radon.

Introduction: Radon ( 222 Rn or 222 radon) is a radioactive gas emitted from building materials, foundations, and soil. Children are especially susceptible to radon exposure, underscoring the need to assess indoor radon levels in kindergartens. This study monitored radon concentrations in 37 Beijing kindergartens from June to October 2023., Methods: A random sample of 37 kindergartens was selected from 18 administrative districts in Beijing. The indoor radon concentration was measured using the solid track accumulation method, with radon detectors continuously monitored over a 3-month period., Results: The mean indoor radon level in 37 kindergartens, observed at 252 monitoring points, was 84.3 Bq/m 3 , with values varying from 12.9 to 263.5 Bq/m 3 . About 20.2% of points showed radon levels between 100.0 and 200.0 Bq/m 3 , while 2.4% exceeded 200.0 Bq/m 3 . Notably, radon levels were significantly elevated on the ground floor compared to the upper floors., Conclusion: Indoor radon levels in 37 kindergartens remained below the national standard limit of 300.0 Bq/m 3 for buildings (GB/T 16146-2015). Nonetheless, 18.9% of the kindergartens exceeded the 100.0 Bq/m 3 limit set for new constructions. It is advised to improve radon monitoring in kindergartens and consider developing a national standard for maximum permissible radon levels in such facilities., Competing Interests: No conflicts of interest., (Copyright and License information: Editorial Office of CCDCW, Chinese Center for Disease Control and Prevention 2024.)

Radon-222 is a naturally occurring radioactive gas arising from the decay of Uranium-238 present in the earth's crust. The knowledge of the radon effects on human health is generating a growing attention by national and international authorities aimed at assessing the exposure of people to this radioactive gas and identifying building types and geographic areas where high indoor radon concentrations (IRCs) are likely to be found. However, given its multi-factorial dependence and the substantial regional variation, the analysis of IRC is not a simple task. There have been several efforts to evaluate the impact of the major influencing factors on IRCs. In this paper we illustrate how the complex relationships between the IRCs and a set of associated variables can be analysed using profile regression, a Bayesian non-parametric model for clustering responses and regressors simultaneously. Analyzing a geo-referenced database of annual IRCs for the Abruzzo region (Central Italy), we show that the proposed methodology allows to identify clusters of buildings according to their proneness to IRCs and that, through cluster assignment, it is possible to disentangle the effect of regressors on IRC and predict its levels for specific combinations of the explanatory variables. [ABSTRACT FROM AUTHOR]

This paper made a continuous measurement of the indoor radon concentrations at a university building in Gyeongju, Rep. of Korea, to check if there is any notable pattern between the indoor radon concentrations and seismic activities. On September 12, 2016, earthquakes with a magnitude of 5.1 and 5.8 consecutively occurred in Gyeongju. 14 months later, an earthquake with a magnitude of 5.5 occurred in Pohang, about 30 km away from Gyeongju, on November 15, 2017. This study investigated the change in the indoor radon concentrations before and after earthquakes to identify if there is any pattern between them and found an interesting pattern. Prior to earthquakes, radon anomalies, which are radon concentration deviating by more than ±2σ from the seasonal average, was usually identified. When 5.0 or greater magnitude earthquakes occurred, the indoor radon concentrations decreased sharply a few days before them, and then continuously increased until the occurrence of the earthquake. [ABSTRACT FROM AUTHOR]

It is commonly known that people are exposed to radon and its progenies since they spend about 35% of daytime at workplaces. This exposure has been reported to be more than 50% of the natural radiation. Therefore, determination of indoor radon concentration has been widely conducted by the scientists. This work presents indoor radon measurements and the associated annual dose equivalents obtained in 28 public buildings of the Afyonkarahisar province. The survey was conducted using passive nuclear track detectors and repeated quarterly during a year. The investigation focused on the seasonal and regional effects in indoor radon concentration anomalies. The measured values ranged from 13 Bq.m-3 to 1,932 Bq.m-3, whereas the calculated average values were in the range of 21.75 Bq.m-3 and 1,032.50 Bq.m-3. Moreover, the mean indoor radon concentration and the corresponding annual dose equivalent values were obtained as 158.83±13.16 Bq.m-3 and 1.25±0.10 mSv.y-1, respectively. [ABSTRACT FROM AUTHOR]

The objective of the present work was to assess the distribution of radon in the University of Technology buildings, Baghdad - Iraq and to identify the effective dose of radon exposure to the staff using passive dosimeter (SSNTD) CR-39. One hundred CR-39 dosimeters were distributed over different buildings in the University campus according to the number of floors area. The exposure time started from December 2012, and the dosimeters were left inside buildings for 40 days. Only 93 dosimeters were collected, while the remaining 7 were considered lost. The average concentrations were calculated in units of Bqm-3, for each sample in each building, and then are repeated after grouping in each floor of the same building. The average radon concentrations per building and at the university as a whole were also calculated. Radon concentrations were found to vary from 80.1 to 416.7 Bqm-3. The highest radon concentration with a mean value of 416.7 Bqm-3 was found atuniversity press section building, while the lowest radon concentration was found at the welding division 2 building with a mean value of 80.1 Bqm-3. The average value of radon concentration at the university was found to have the value of 181.9 Bqm-3 which is less than the recommended value of 200 Bqm-3 UNSCEAR [18]. Dose rate (in µSv/h), annual dose rate (in mSv/y & WLM/y), cumulative dose (in mSv& WLM) and cancer risk were also calculated. It was found that the university staffs are exposed annually to 2.083 mSv which equal to 0.231 Working Level Month (WLM) from radon gas and its short-lived daughters. Hence, a person takes on the average an annual effective dose equivalent to 2.56and 1.84mSv according to average value considered by UNSCEAR [18] and ICRP [19], respectively. This implies an expected value for lung cancer probability of 0.0046.

The presented, very simplified model provides a possibility for estimation of surface Pb-210 activity, depending on the changes of Rn-222 concentration during the long-term radon presence inside the closed room. This can be useful for retrospective assessment of the average indoor radon concentration for certain historical period, based on the surface contamination by the radionuclide Pb-210 in a closed or poorly ventilated room over a long period of time. However, the surface Pb-210 contamination depends on the pattern of radon concentration changes, and in this model is supposed that the change of indoor radon concentration, which periodically enters the room, is affected only by the radioactive decay and the inserted amount of radon in each entry. So, each radon entry can be comprehended as a “net amount” of radon, or excess which remains inside the room due to radon’s periodical in-out flow. It is shown, that under the conditions of the model, the achieved average value of radon concentration of 275 Bq/m3, implies that the saturated surface contamination by the Pb-210 of 160 Bq/m2 after approximately 150 years. [Projekat Ministarstva nauke Republike Srbije, br. 171002: Nuclear Methods Investigations of Rare Processes and Cosmic Rays i br. 43002: Biosensing Technologies and Global System for Continuous Research and Integrated Management of ecosystems]

Results of indoor radon survey in the dwellings of district Bhimber are presented. Current study is continuation of our preceding studies aiming to setup baseline indoor radon data for the state of Azad Jammu & Kashmir, Pakistan. In this context, 60 representative houses were carefully selected and CN-85 based box type radon detectors were installed in bedrooms and living rooms of each house. The detectors were exposed to indoor radon for 90 days. After etching CN-85 detectors in 6M NaOH at 70°C for 3 hours, the observed track densities were related to the indoor radon concentration using calibration factor of 0.0092 tracks cm2/h per Bq/m3. The measured indoor radon concentration ranged from 29 ± 11 to 58 ± 8 Bq/m3, 40 ± 9 to 60 ± 7 Bq/m3, and 29 ± 12 to 66 ± 7 Bq/m3 in the regions of Bhimber, Samani, and Barnala, respectively. Excess relative risk factors were calculated using measured indoor radon concentrations, by using the risk model reported in the Biological Effects of Ionizing Radiation (BEIR VI, 1999) report. Excess relative risk was calculated for age groups of 35 and 55 years. Using local occupancy factor, average excess lung cancer risk for the population group of 35 and 55 years of age was found to be 0.42 ± 0.09 and 0.34 ± 0.08. The mean annual effective dose for Bhimber, Samani, and Barnala regions were found to be 1.05 ± 0.17 mSv, 1.09 ± 0.17 mSv, and 1.16 ± 0.17 mSv, respectively. These values are within in the safe limits recommended by the international organizations.

Abstract: Building materials are the second major source of indoor radon after soil. The contribution of building materials towards indoor radon depends upon the radium content and exhalation rates and can be used as a primary index for radon levels in the dwellings. The radon flux data from the building materials was used for calculation of the indoor radon concentrations and doses by many researchers using one and two dimensional model suggested by various researchers. In addition to radium content, the radon wall flux from a surface strongly depends upon the radon diffusion length (L) and thickness of the wall (2d). In the present work the indoor radon concentrations from the measured radon exhalation rate of building materials calculated using different models available in literature and validation of models was made through measurement. The variation in the predicted radon flux from different models was compared with d/L value for wall and roofs of different dwellings. The results showed that the radon concentrations predicted by models agree with experimental value. The applicability of different model with d/L ratio was discussed. The work aims to select a more appropriate and general model among available models in literature for the prediction of indoor radon. [Copyright &y& Elsevier]

We present an overview of the potential of active monitoring techniques to investigate the many factors affecting the concentration of radon in houses. We conducted two experiments measuring radon concentration in 25 apartments in Rome and suburban areas for two weeks and in three apartments in the historic center for several months. The reference levels of 300 and 100 Bq/m 3 are overcome in 17% and 60% of the cases, respectively, and these percentages rise to 20% and 76% for average overnight radon (more relevant for residents' exposure). Active detectors allowed us to identify seasonal radon fluctuations, dependent on indoor-to-outdoor temperature, and how radon travels from the ground to upper floors. High levels of radon are not limited to the lowest floors when the use of heating and ventilation produces massive convection of air. Lifestyle habits also reflect in the different values of gas concentration measured on different floors of the same building or in distinct rooms of the same apartment, which cannot be ascribed to the characteristics of the premises. However, the finding that high residential radon levels tend to concentrate in the historic center proves the influence of factors such as building age, construction materials, and geogenic radon.

Abstract: Indoor radon is regularly measured in Switzerland. However, a nationwide model to predict residential radon levels has not been developed. The aim of this study was to develop a prediction model to assess indoor radon concentrations in Switzerland. The model was based on 44,631 measurements from the nationwide Swiss radon database collected between 1994 and 2004. Of these, 80% randomly selected measurements were used for model development and the remaining 20% for an independent model validation. A multivariable log-linear regression model was fitted and relevant predictors selected according to evidence from the literature, the adjusted R², the Akaike''s information criterion (AIC), and the Bayesian information criterion (BIC). The prediction model was evaluated by calculating Spearman rank correlation between measured and predicted values. Additionally, the predicted values were categorised into three categories (50th, 50th–90th and 90th percentile) and compared with measured categories using a weighted Kappa statistic. The most relevant predictors for indoor radon levels were tectonic units and year of construction of the building, followed by soil texture, degree of urbanisation, floor of the building where the measurement was taken and housing type (P-values <0.001 for all). Mean predicted radon values (geometric mean) were 66 Bq/m³ (interquartile range 40–111 Bq/m³) in the lowest exposure category, 126 Bq/m³ (69–215 Bq/m³) in the medium category, and 219 Bq/m³ (108–427 Bq/m³) in the highest category. Spearman correlation between predictions and measurements was 0.45 (95%-CI: 0.44; 0.46) for the development dataset and 0.44 (95%-CI: 0.42; 0.46) for the validation dataset. Kappa coefficients were 0.31 for the development and 0.30 for the validation dataset, respectively. The model explained 20% overall variability (adjusted R²). In conclusion, this residential radon prediction model, based on a large number of measurements, was demonstrated to be robust through validation with an independent dataset. The model is appropriate for predicting radon level exposure of the Swiss population in epidemiological research. Nevertheless, some exposure misclassification and regression to the mean is unavoidable and should be taken into account in future applications of the model. [Copyright &y& Elsevier]

Radon is the only alpha emitting radioactive gas. Inhalation of radon and radon daughters may cause serious health risks. Thus, it is crucial to determine indoor radon concentrations. In this study, radon level measurements have been presented for Prof. Dr. Hasan Gürbüz Information Center, which has 8000 square meters closed area, in Silleyman Demirel University. Measurements were performed by Using passive nuclear etched track detectors. For this purpose, CR-39 detectors were placed into 20. measurement points in the Information Center for a 67 days period between December 2008 and February 2009. It was found that the average radon concentration of the center was 188 Bq/m3. Furthermore, in three measurement points high radiation levels were recorded, which were higher than the 500 Bq/m3 that is the lower limit value of ICRP (International Commission on Radiological Protection) for the work places. As a result, annual equivalent dose values for library users, full-time and part-time staff have been calculated as 0,49 mSv/y, 1,97 mSv/y and 0,98 mSv/y respectively. Necessary precautions that might be taken for the locations with high radon levels were also considered. [ABSTRACT FROM AUTHOR]

Using high-sensitivity radon (222Rn) portable detectors (passive electronic devices of the type RADIM3), the airborne 222Rn concentration in the interior of various Cypriot buildings and dwellings was measured. For each preselected building and dwelling, a calibrated detector was put into a closed room, and the 222Rn concentration was registered in sampling intervals of 2 to 4 h for a total counting time of typically 48 h. 222Rn activity concentrations were found to be in the range of 6.2 to 102.8 Bq m−3, with an overall arithmetic mean value of (19.3±14.7) Bq m−3. This value is by a factor of two below the world average (population-weighted) value of 39 Bq m−3. The total annual effective dose equivalent to the Cypriot population was calculated to be between 0.16 and 2.6 mSv with an overall arithmetic mean value of (0.49±0.37) mSv. [Copyright &y& Elsevier]

The article presents the results of radon research, carried out in the area of the mining commune in the Upper Silesian Coal Basin (USCB), Poland. Past investigations in the 1990s on radon concentrations in buildings, located within the mining area, showed that the indoor radon concentrations measured in the area affected by mining were higher than in buildings located outside that area. Currently, all underground hard coal mines within the boundaries of the observed commune have been closed. In 2020, after the closure of the last active mine, radon measurements were started again. The current results of indoor radon concentrations were compared with the archival results from the 1990s. It was found that the radon concentration increased significantly in the basements of buildings where measurements were made in 1990, 2020, and 2021: the maximum values were 260 Bq/m 3 , 644 Bq/m 3 , and 1041 Bq/m 3 , respectively. Therefore, these questions were posed: Do the mine closure processes increase radon migration? How long is the period of the occurrence of changes in radon concentrations in buildings after the cessation of mining operations?

The performance of continuous radon monitors (CRMs) is usually evaluated under controlled conditions in a radon chamber during calibrations or intercomparison exercises. The impact of thoron on CRMs response is rarely evaluated; in case the evaluation is performed, it is carried out in a controlled atmosphere with relatively constant, homogeneous, and generally high thoron concentrations and very low radon levels. In a real indoor environment, both radon and thoron concentrations are extremely variable, so the thoron interference evaluations reported in the literature are generally not applicable to CRMs used to measure radon concentration indoors. For this reason, an experimental study was carried out with four different CRMs in an indoor environment (an office room) where medium-to-high concentrations of both radon and thoron were expected. Thoron concentration has been separately evaluated throughout two different active monitors. Three CRMs resulted in overestimations of radon concentration by about 10% due to thoron interference, whereas such interference results were negligible for the fourth CRM. However, the thoron interference can also be used to assess thoron concentration by using CRM not specifically designed to do so. Based on the results of this study, an indirect method to assess thoron concentration is indeed proposed, relying on the combination of two identical monitors (one placed right close to the wall and the other one far enough from there).

In the present study, we aimed to determine the changes of indoor radon concentrations depending on various environmental parameters, such as the outdoor temperature, relative humidity, and air pressure, in university building premises of different applications and heights. The environmental parameters and indoor radon concentrations in four different premises were measured each working day over an eight-month period. The results showed that the indoor radon levels strongly depended on the outside temperature and outside relative humidity, whereas the weakest correlations were found between the indoor radon levels and indoor and outdoor air pressures. The obtained indoor radon concentration and environmental condition correlations were different for the different premises of the building. That is, in two premises where the ventilation effect through unintentional air leakage points prevailed in winter, positive correlations between the radon concentration and outside temperature were obtained, reaching the values of 0.94 and 0.92, respectively. In premises with better airtightness, negative correlations (R = −0.96 and R = −0.62) between the radon concentrations and outside temperature were obtained. The results revealed that high quality air isolation in premises could be an important factor for higher indoor radon levels during summer compared to winter. [ABSTRACT FROM AUTHOR]

Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Radon-222 is a radioactive natural gas produced by the decay of radium-226, known to be the main contributor to natural background radiation exposure. Effective risk management needs to determine the areas in which the density of buildings with high radon levels is likely to be highest. Predicting radon exposure from the location and characteristics of a dwelling could also contribute to epidemiological studies. Beginning in the nineteen-eighties, a national radon survey consisting in more than 10,000 measurements of indoor radon concentrations was conducted in French dwellings by the Institute for Radiological Protection and Nuclear Safety (IRSN). Housing characteristics, which may influence radon accumulation in dwellings, were also collected. More recently, the IRSN generated a French geogenic radon potential map based on the interpretation of geological features. The present study analyzed the two datasets to investigate the factors influencing indoor radon concentrations using statistical modeling and to determine the optimum use of the information on geogenic radon potential that showed the best statistical association with indoor radon concentration. The results showed that the variables associated with indoor radon concentrations were geogenic radon potential, building material, year of construction, foundation type, building type and floor level. The model, which included the surrounding geogenic radon potential (i.e. the average geogenic radon potential within a disc of radius 20 km centered on the indoor radon measurement point) and variables describing house-specific factors and lifestyle explained about 20% of the overall variability of the logarithm of radon concentration. The surrounding geogenic radon potential was fairly closely associated with the local average indoor radon concentration. The prevalence of exposure to radon above specific thresholds and the average exposures to radon clearly increased with increasing classes of geogenic radon potential. Combining the two datasets enabled improved assessment of radon exposure in a given area in France., (Copyright © 2013 Elsevier Ltd. All rights reserved.)