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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]

A 222Rn survey and analysis for dwellings in Edirne (Türkiye) were performed to secure the radiological safety of persons and to provide information on the reduction of 222Rn exposure. Measurements of the 222Rn activity concentration, together with meteorological conditions were carried out using an AlphaGuard 2000 Pro monitor. Excess lifetime cancer risks (ELCRs) and annual effective dose rates (AEDs) were estimated to indicate associated human health risks. The mean indoor radon concentration was within the reference value of 200–300 Bq m−3 as suggested by International Commission on Radiological Protection (ICRP) and World Health Organization (WHO). [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]

In order to assess the radiological impact of radon on >250,000 students, the total annual effective dose was estimated inside 204 Moroccan primary schools sampled in the Doukkala-Abda region. The measurement of indoor radon concentrations was conducted using the LR115 detector for each month, each season and throughout the year. The evolution of indoor radon concentrations showed a decrease in annual average radon concentrations of 20–26% and 10–14%, respectively, compared to the monthly and seasonal annual average radon concentrations. For this purpose, a corrective model of short-term radon concentrations was developed to calculate the seasonal correction factors in order to estimate the annual indoor radon concentrations. For the qualitative evaluation of these factors, a percentage of deviation between the measured and estimated annual radon concentrations was calculated. Almost half of the estimated annual concentrations were 10% less than the measured concentration and the majority of these estimated values were within 40%. The estimated total annual effective doses received by students, except those in the Sidi Bennour city, were higher than the world average (1.15 mSv/y). Nevertheless, all these doses remained below the permissible limit recommended by the International Commission on Radiological Protection (3–10 mSv/y). [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).

Annual average indoor radon activity concentration was studied in 88 Hungarian kindergartens in 76 towns of 10 different counties. Annual average indoor radon activity concentration in the kindergartens was 61 Bq m− 3, maximum was 160 Bq m− 3. In the kindergartens the seasonal variation of radon is not so strong like in dwellings, because of the permanent ventilation and the closed period during the summer break. [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 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]

Purpose: Soil is the prime source of radon and thoron concentrations in the household dwellings. The presence of radioactive gases in the environment is mainly due to the presence of radionuclide content in soil, rocks, and building materials. So, it is necessary to estimate the radionuclide content in the living environment. The annual effective dose has been assessed from the radionuclide content, and an effort has been made to correlate the concentration of these radionuclides with exhalation rates of their daughter products, i.e., radon and thoron. Theoretically determined indoor radon concentration has also been compared with experimentally observed results.Material and methods: Scintillation-based Smart RnDuo monitor (SRM) and gamma spectrometry (NaI(Tl)) have been utilized for the estimation of exhalation rates and radionuclide (226Ra, 232Th, and 40K) contents in soil samples.Results and discussions: The range of radon mass and thoron surface exhalation rate in soil samples are found to vary from 11.57 to 65.62 mBq kg−1 h−1 with an average of 28.20 mBq kg−1 h−1 and from 52 to 930 mBq m−2 s−1 with an average of 312 mBq m−2 s−1, respectively. The average activity concentrations of 226Ra, 232Th, and 40K are 24.52 Bq kg−1, 41.15 Bq kg−1, and 343 Bq kg−1, respectively.Conclusions: The average values of 226Ra, 232Th, and 40K are well within the safe range recommended by the United Nations Scientific Committee on the Effects of Atomic Radiations. The calculated annual effective dose and radiation hazard risks have been found to be well below the recommended levels. Results obtained from theoretical evaluation are compared with experimentally obtained results and are in good agreement with each other. Different occupancy factors have also been analyzed according to the populace indoor occupancy. [ABSTRACT FROM AUTHOR]

In the present study, the soil-gas radon concentration was assessed at different depth intervals, i.e., 15 cm, 30 cm, 60 cm, and 100 cm from the 30 villages of Jammu & Kashmir, India using RAD7, an electrostatic solid state alpha detector. The radon mass exhalation and thoron surface exhalation rate has also been measured in the selected 18 soil samples out of 30 of different grain sizes (i.e., 1 mm, 300 µm, 150 µm). The active radon and thoron concentrations were also assessed in the 20 villages. Both the exhalation rates and active radon/thoron concentration were measured using SMART Rn Duo, a portable radon monitor. The average values of soil-gas radon concentration were 210 ± 84 Bq m−3, 1261 ± 963 Bq m−3, 4210 ± 1994 Bq m−3, and 671 ± 305 Bq m−3 at the depth intervals of 15 cm, 30 cm, 60 cm, and 100 cm, respectively. The exhalation rate of radon and thoron from soil was found to decrease with the increase of grain size, as smaller soil particles make relatively more contribution to radon and thoron exhalations from the ground surface than larger soil particles. The measured Pearson's correlation coefficient was obtained as statistically significant between different quantities under two-tailed test. [ABSTRACT FROM AUTHOR]

In this study, indoor (air) and tap water Radon ( 222 Rn) measurements were performed at various campus areas of Giresun University. The measurement and analysis results were compared with the values recommended by international and national organizations and those reported in literature studies. The measured and calculated values were found to be under the recommended limits. Also, annual effective dose values were evaluated to determine the annual radon exposure of an individual working in the measurement area. Indoor radon concentration values measured by CR-39 detectors were in the range of 76 Bq/m 3 –504 Bq/m 3 and the mean concentration value was obtained as 193.7 Bq/m 3 . The radon concentrations in tap water samples were found to be in the range of 0.98 Bq/L–27.28 Bq/L. The annual mean effective doses ( E Wig ) of drinking water samples were calculated in the range of 9.9–150.4 (μSv/y) for ingestion and 0.97–14.84 (μSv/y) for inhalation calculations. Excess life time cancer risk (ELCR ) was estimated as 0.54%. Radon dose rate in terms of mean annual working level month was calculated as 0.246 WLM/year. The study was performed with a view to contribute to further studies in the related field and constitute a basis for the measurements conducted in this area. [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 study was conducted to assess the spatiality of the building factors' effect on air quality through evaluation of indoor radon concentration in areas with different geology and geographical position. For that matter, a survey of indoor radon concentration was carried out in 174 kindergartens of three Bulgarian cities. The time-integrated measurements were performed in 777 ground floor rooms using alpha tract detectors, exposed for 3 months in cold period of 2014. The results of indoor radon concentrations vary from 20 to 1117 Bq/m. The differences in the mean radon concentrations measured in the different cities were related to geology. The effect of building-specific factors: elevator, basement, mechanical ventilation, type of windows, number of floors, building renovation, building materials, type of room, type of heating, construction period, and availability of foundation on radon concentration variations was examined applying univariate and multivariate analysis. Univariate analysis showed that the effects of building-specific factors on radon variation are different in different cities. The influence of building factors on radon concentration variations was more dominant in inland cities in comparison to the city situated on the sea coast. The multivariate analysis, which was applied to evaluate the impact of building factors simultaneously, confirmed this influence too. [ABSTRACT FROM AUTHOR]

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.

The areas pertaining the hydrocarbon and non-hydrocarbon in the Attock district of Pakistan were selected for the measurement of indoor radon concentration. This area was not previously surveyed for such kind of study. CR-39-based NRPB radon dosimeters were utilized for this study. Attock city, Hassan Abdal and Jand belong to the non-hydrocarbon areas, where radon concentration was measured to be 57 ± 11, 58 ± 11 and 56 ± 11 Bq m−3, respectively. The hydrocarbon pertaining areas consist of Toot and Meyal villages, the concentration of radon was found to be 48 ± 10 and 37 ± 8 Bq m−3, respectively. The cap rock in the geological structures of the hydrocarbon areas may have restricted the migration of underneath radon. The annual effective dose in the studied locations was estimated to be 1.28 ± 0.25 mSv y−1, which is less than the action level recommended by the ICRP. Estimated excess lung cancer risks per million persons per year in the surveyed area show higher values 96, 69, 32–110 and 41–124 as compared to the world average reported by the BEIR-IV (1988), ICRP (1987), US-EPA (1986) and UNSCEAR (1993) models, respectively. Present results could be used as a reference for any future studies in Pakistan for the problems of radon emissions with respect to the types of rocks. [ABSTRACT FROM AUTHOR]

Radon is a radioactive gas which is present everywhere on the earth with different proportions according to the place. Known as an alpha emitter, the World Health Organization (WHO) declared it as carcinogenic for lungs since 1987. In order to prevent the population of Côte d’Ivoire from the health risks linked to radon, several indoor measurements have been carried out in the District of Abidjan (capital of Côte d’Ivoire), precisely in Abobo, the commune with the second national highest population rate. 18 sites have been selected in this commune for radon concentration monitoring using the Solid State Nuclear Tracks Detectors (SSNTD) technique.Radon concentrations measured in Abobo vary from 27.5 to 211.2 Bq.m-3 with an average of 113 Bq.m-3. Our results are analyzed and compared to the limit levels in other countries and also to those recommended by the WHO and the International Agency for Research on Cancer (IARC). Except one site, most of our values are far inferior to international limits standards. Moreover, the Excess lung Cancer Risk (ECR) has been evaluated. Some protection measures have been proposed in order to reduce indoor radon concentration and the number of lung cancer related to radon in Côte d’Ivoire. [ABSTRACT FROM AUTHOR]

A comprehensive grid-based study of indoor Rn concentration in all accessible urban areas of the Republic of Cyprus, where 67.3% of the population resides, is presented. During the years 2004–2012, a total of 407 measurements of indoor Rn in the four highly-populated urbanised areas of Lefkosia, Lemesos, Larnaka, and Pafos districts were conducted, using high-sensitivity active Rn portable detectors. The four districts were subdivided into 189 grid cells, each of 1 km 2 in area. The grid cell mean indoor Rn concentration is in the range of 1.7 to 86.4 Bq/m 3 , with an overall geometrical mean of 14.3 ± 10.0 Bq/m 3 , and a median of 14.3 ± 3.9. The Rn mean in Cyprus is almost two-and-a-half times lower than the estimated world average of 39 Bq/m 3 . The equivalent annual effective dose rate for each measurement was also calculated and compared to the corresponding world value. The spatial distribution and variation of Rn concentration values are also shown on maps of the urban areas of these districts. The conclusion of the present extensive and systematic Rn survey is that the Rn risk in the highly populated areas of Cyprus is low. [ABSTRACT FROM AUTHOR]

Radon-222 is a noble gas arising naturally from decay of uranium-238 present in the earth's crust. In confined spaces, high concentrations of radon can become a serious health concern. Hence, experts widely agree that prolonged exposure to this gas can significantly increase the risk of lung cancer. A range of variables, such as geological factors, soil properties, building characteristics, the living habits of dwellers and meteorological parameters, might have a significant impact on indoor radon concentration and its variability. In this paper, the effect of various factors that are believed to influence the indoor radon concentrations is studied at the municipal level of L'Aquila district (Abruzzo region, Italy). The statistical analysis is carried out through a hierarchical Bayesian spatial quantile regression model in which the matrix of explanatory variables is partially defined through a set of spatial common latent factors. The proposed model, here referred to as the Generalized latent-spatial-quantile regression model, is thus appropriate when some covariates are indicators of latent factors that can be used as predictors in the quantile regression and the variables are supposed to be spatially correlated. It is shown that the model has an intuitive appeal and that it is preferable when the interest is in studying the effects of covariates on one or both the tails of the response distribution, as in the case of indoor radon concentrations. Full probabilistic inference is performed by applying Markov chain Monte Carlo techniques. [ABSTRACT FROM AUTHOR]

In order to carry out indoor radon measurement in new and old buildings of the Dera Ismail Khan city, CR-39 based radon detectors were installed in bed rooms and sitting rooms/TV lounges in 25 (each) old and new houses and were exposed to indoor radon for 90 days. After processing, mean weighted average indoor radon concentrations in old and new houses were found to be 275 ± 33 and 86 ± 18 Bq m whereas mean annual effective doses expected to be received by the occupants were 6.86 ± 0.79 and 2.1 ± 0.43 mSv year, respectively. From the measured weighted average indoor radon concentration, excess relative risk factor was calculated using the risk model of BEIR VI for the age group of 35 and 55 years. Average excess lung cancer risk was found to be 1.63 ± 0.19 and 1.35 ± 0.16 and 0.5 ± 0.10 and 0.4 ± 0.08 for old and new houses, respectively. [ABSTRACT FROM AUTHOR]