Radon Concentration In Buildings Research Articles

Factors Affecting Indoor Radon Levels in Buildings Located in a Karst Area: A Statistical Analysis

In this paper, the averages annual radon concentrations in buildings placed in a karst area are analyzed in order to understand which factors may affect the occurrence of high levels of radon indoor. Statistical analysis on the radon dataset is performed using analytical factors described by two or three levels according to the characteristic of the measured buildings. The factors that determine higher radon levels in terms of arithmetic mean (AM) at ground floor (GF) are mainly the presence of sedimentary calcareous rock (SCR) in walls and the direct attack or crawl space as type of foundation. At first floors (FF), the presence of walls of only SCR showed radon levels higher (in terms of AM) than the one found for walls of mixed typology. These outcomes suggest that in karstic area buildings with SCR as the main construction material and direct attack or crawl space as the type of foundation, can be considered as radon-prone buildings. Moreover, this study confirms the need to measure radon levels not only at below ground floor and at GF, but also at FF and above for buildings in karst areas with construction materials including SCR blocks.

Temporal Variation in Indoor Radon Concentrations Using Environmental Public Health Tracking Data.

Indoor radon is the second leading cause of lung cancer in the United States (US) after smoking and the number one for lung cancer in non-smokers. Understanding how indoor radon varies during the year reveals the best time to test to avoid underestimating exposure. This study looks at the temporal variation in 13 years of radon concentrations in buildings located in 46 US states and the District of Columbia (DC). In the dataset, radon concentration varies from 3.7 Bq m -3 (Becquerels per cubic meter) to 52,958.1 Bq m -3 , with an overall mean of 181.4 Bq m -3 . About 35.4% of tests have a radon concentration level equal to or greater than the US Environmental Protection Agency (US EPA) action level 4.0 pCi L -1 (148 Bq m -3 ). 3 Temporal variation in radon concentrations was assessed using the overall monthly mean radon concentration. The highest concentrations were found in January (203.8 Bq m -3 ) and the lowest in July (129.5 Bq m -3 ). Higher monthly mean indoor radon concentrations were found in January, February, and October, and lower in July, August, and June. This result is consistent with findings from other studies and suggests continuing to encourage radon testing throughout the year with an emphasis on testing during the colder months.

Status of the geogenic radon potential investigations in Bulgaria

Radon (222Rn) is a radioactive gas and formed as a result of the radioactive decay of radium. 222Rn relieved from the ground could accumulate in the building and contribute to human exposure. Exposure to indoor radon and its decay products contributes to half of the annual dose received by the public from all natural radioactive sources. Radon is recognized as a carcinogenic agent by the WHO and is the second leading cause of lung cancer after tobacco smoke. The radon concentration in buildings and the exposure to radon depend on many factors, but it can be assumed that geology is the main factor influencing the variation of indoor radon. In this regard, the geogenic radon potential (GRP) of the terrain is the probability of the presence of high radon concentration in a building, the genesis of which is directly related to the influence of the earth's surface, and not e.g. from building materials. In addition, there is a concept “radon index”, which is used to characterize GRP. One of the approaches for quantifying the radon index is based on a multivariate cross-tabulation, which includes two parameters – radon concentration in soil gas and gas permeability of the earth layer. Till 2019, complex studies concerning correlation between the measured radon concentrations and bedrock geology in Bulgaria are only scarce and quite general. In the last three years, there are attempts for detailed investigations for evaluation of the bedrock and superficial geology associating with radon potential or/and radon index determinations. Therefore, research works on geogenic radon so far in Bulgaria can be divided into two main groups: regional research works related to the "radon-rock" relationship and local research aimed at determining the radon index at specific sites. In the first group appertain investigations about defining the rock formations in Bulgaria, in their outcrop presence, with possible high radon potential based on geological and published more general “radon–rock correlations” data. Based on that, a GIS based map for the spatial distribution of the particular rock types in accordance with the expected radon potential is made. Also to this group belongs a study concerning spatial sampling design for the use of the polygons (Sliven Province) as the unit of sampling, data collection, and analysis and reduces the number of observations, as well as would optimize the gathering, analysis and systematization of the data for the preparation of a methodology for the preparation of geogenic radon potential map. In the second group appertain investigations of the radon index determination at the two pilot sites affected by fault systems in Sofia.

Radon Concentrations in Dwellings in the Mining Area-Are There Observed Effects of the Coal Mine Closure?

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/m3, 644 Bq/m3, and 1041 Bq/m3, 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?

Radon in Indoor Air: Towards Continuous Monitoring

Radon poses significant health risks. Thus, the continuous monitoring of radon concentrations in buildings’ indoor air is relevant, particularly in schools. Low-cost sensors devices are emerging as promising technologies, although their reliability is still unknown. Therefore, this is the first study aiming to evaluate the performance of low-cost sensors devices for short-term continuous radon monitoring in the indoor air of nursery and primary school buildings. Five classrooms of different age groups (infants, pre-schoolers and primary school children) were selected from one nursery and one primary school in Porto (Portugal). Radon indoor concentrations were continuously monitored using one reference instrument (Radim 5B) and three commercially available low-cost sensors devices (Airthings Wave and RandonEye: RD200 and RD200P2) for short-term sampling (2–4 consecutive days) in each studied classroom. Radon concentrations were in accordance with the typical profiles found in other studies (higher on weekends and non-occupancy periods than on occupancy). Both RadonEye low-cost sensors devices presented similar profiles with Radim 5B and good performance indices (R2 reaching 0.961), while the Airthings Wave behavior was quite different. These results seem to indicate that the RadonEye low-cost sensors devices studied can be used in short-term radon monitoring, being promising tools for actively reducing indoor radon concentrations.

A pilot survey on indoor radon concentration in Beijing

ObjectiveTo 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. MethodsA 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. ResultsThe 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. ConclusionsThere 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.

Comparative analysis of radon concentrations in buildings of different energy efficiency classes on example of five Russian cities

A comparative analysis of the radon concentrations in modern multi-storey residential buildings of high energy efficiency class and buildings typical for urban areas of the twentieth century was carried out. The study was conducted in Russian cities located in various climatic zones – Ekaterinburg, Krasnodar, St. Petersburg, Salekhard, Chelyabinsk. The radon concentration in samples of buildings was measured using integrated radon radiometers based on nuclear track detectors according to a single method. The surveyed sample included 498 apartments in multi-apartment buildings. Among all the examined building types, the highest average radon concentration is observed in modern energy-efficient houses – 43 Bq/m3. In other types of buildings, the following average radon concentrations were obtained: brick 2–5 floors – 35 Bq/m3; panel 5 floors – 32 Bq/m3; panel 7–12 floors 1970-1990 years of construction – 22 Bq/m3; brick> 5 floors 1970–1980 years of construction – 20 Bq m3; panel, built since 1990 – 24 Bq/m3. The results of the study confirm the assumption that radon concentration in modern multi-storey energy-efficient houses is on average higher than in typical residential buildings of the Soviet period. The increased accumulation of radon in energy-efficient buildings is associated with a decrease in the building envelope permeability and the contribution of fresh air to the general air exchange. Despite the fact that there were no cases of exceeding hygienic standards for the indoor radon concentration in the framework of this study, the higher radon concentration in buildings of increased energy efficiency requires attention from the point of view of implementing the principle of optimization of radiation protection. In the future, extensive construction of energy-efficient buildings may increase the average and collective doses to the urban population in the Russian Federation.

Radon on the ground floor in the buildings of pre-university education in Montenegro

Abstract A national radon survey was performed recently in all buildings of pre-university education in Montenegro. During the school year 2016/2017, radon (222Rn) was measured with passive detectors (Radosys, RSFV type) in 2855 ground-floor rooms of 468 buildings. The average 9-month radon activity concentrations above the level of 300 Bq/m3 were found in 728 rooms, which belong to 213 buildings, while in 111 rooms, belonging to 47 buildings, they were above 1000 Bq/m3. Radon concentrations in the educational buildings, averaged over all sampled ground-floor rooms in a building, range from 16 Bq/m3 to 2810 Bq/m3, with arithmetic mean (AM) = 275 Bq/m3. They follow a log-normal distribution with geometric mean (GM) = 174 Bq/m3 and geometric standard deviation (GSD) = 2.58. There are 135 buildings with average indoor radon concentrations on the ground floor above 300 Bq/m3 and 18 buildings where they are above 1000 Bq/m3. The influence of the nine factors (climate, urban/rural area, age of building, number of stories, building materials, basement, foundation slab, window frames, and heating) on radon concentrations in the buildings was analysed by univariate (UVA) and multivariate (MVA) methods. The univariate analysis revealed the significant relationship of the four factors: age of buildings, basement, building materials, and window frames with radon concentrations on the ground floor in the buildings, while multivariate analysis added to those factors urban/rural area and number of stories, but excluded building materials as a factor influencing significantly radon concentrations.

Radon Concentration in Buildings in the South Region of Kingdom of Saudi Arabia

Radon Concentration in Buildings in the South Region of Kingdom of Saudi Arabia

Radon Concentration in Buildings in the South Region of Kingdom of Saudi Arabia

Radon Concentration in Buildings in the South Region of Kingdom of Saudi Arabia

Reducing the risks from radon indoors: an IAEA perspective.

The IAEA has a mandate to develop, in collaboration with other relevant international organisations, 'standards of safety for protection of health and minimisation of danger to life and property', and to provide for the application of these standards. The most recent edition of the International Basic Safety Standards includes, for the first time, requirements to protect the public from exposure due to radon indoors. As a result, the IAEA has already developed guidance material in line with accepted best international practice and an international programme to assist its Member States in identifying and addressing high radon concentrations in buildings is being prepared. This paper overviews the current situation around the world and summarises the management approach advocated by the IAEA. A number of important scientific and policy issues are identified and discussed from the point-of-view of how they may impact on national action plans and strategies. Finally, the assistance and support available through the Agency is described.

Assessment of Radon Concentrations Inside a High School Building in Guarda (Portugal): Legislation Implications and Mitigation Measures Proposed

The maximum accepted radon concentration in buildings represents the national reference level for radon and is an important parameter in the indoor air quality (IAQ). In Portugal, national regulations defines the maximum concentrations of 400 Bq/m3 of radon, being there search mandatory only in dwellings in granitic areas as Guarda district. With the aim of assessing the average values of indoor radon, it was made a study of radon concentrations inside of Instituto Politécnico da Guarda (IPG). It was used a continuous Radon Monitoring equipment for real-time measurements in two different periods – winter and summer. The results obtained show an IAQ for radon gas above 400 Bq/m3, with some seasonal variations, as well as variations related to the occupation of these divisions.According to that some mitigation solutions are proposed.

Counting radon tracks in Makrofol detectors with the “image reduction and analysis facility” (IRAF) software package

Makrofol detectors are commonly used for long-term radon ( 222Rn) measurements in houses, schools and workplaces. The use of this type of passive detectors for the determination of radon concentrations requires the counting of the nuclear tracks produced by alpha particles on the detecting material. The “image reduction and analysis facility” (IRAF) software package is a piece of software commonly used in astronomical applications. It allows detailed counting and mapping of sky sections where stars are grouped very closely, even forming clusters. In order to count the nuclear tracks in our Makrofol radon detectors, we have developed an inter-disciplinary application that takes advantage of the similitude that exist between counting stars in a dark sky and tracks in a track-etch detector. Thus, a low cost semi-automatic system has been set up in our laboratory which utilises a commercially available desktop scanner and the IRAF software package. A detailed description of the proposed semi-automatic method and its performance, in comparison to ocular counting, is described in detail here. In addition, the calibration factor for this procedure, 2.97 ± 0.07 kBq m - 3 h track - 1 cm 2 , has been calculated based on the results obtained from exposing 46 detectors to certified radon concentrations. Furthermore, the results of a preliminary radon survey carried out in 62 schools in Tenerife island (Spain), using Makrofol detectors, counted with the mentioned procedure, are briefly presented. The results reported here indicate that the developed procedure permits a fast, accurate and unbiased determination of the radon tracks in a large number of detectors. The measurements carried out in the schools showed that the radon concentrations in at least 12 schools were above 200 Bq m - 3 and, in two of them, above 400 Bq m - 3 . Further studies should be performed at those schools following the European Union recommendations about radon concentrations in buildings.

Seasonal changes in radon concentrations in buildings in the region of northeastern Poland

In this study, seasonal observations of radon concentration changes inside buildings carried out in the northeastern region of Poland is presented. One-year measurements of radon concentrations were performed in chosen buildings. The integral method of Cr-39 trace detectors in diffusive chambers was used. Mean values of radon concentrations were determined in monthly, 2-, 3-, 6-month, and annual observations. The fraction of a mean annual concentration of the value obtained in a shorter observation was calculated. Monthly concentration values were from about 0.2 to 14.9 of the annual mean. All buildings revealed seasonal fluctuation of radon concentration. Negative correlation of indoor radon concentration in the buildings and the mean temperature outside was observed in most examined buildings. The lowest coefficient range, determining which part of the annual mean value would be obtained in the 6-month observation, was gained for exposure begun in April or October.

The regional distribution of indoor radon concentration in Germany

According to the recommendations of the ICRP and the German Commission on Radiological Protection, areas should be identified where increased radon concentrations in buildings occur more frequently than on the countrywide average. Based on investigations of radon concentration in soil air, the areas of Germany have been classified. Comparing the soil gas classes with the radon concentrations in dwellings, we found that in regions with a soil gas radon concentration of up to 10 kBq/m 3 (about 25% of the total area of Germany), the probability that indoor concentrations above 400 Bq/m 3 occur is in the order of 0.1%; values of more than 1000 Bq/m 3 can be excluded. The assessment of about 20 000 indoor measurements in areas with radon concentrations in soil air in the range between 10 and 100 kBq/m 3 showed that radon concentrations >400 Bq/m 3 occur only in 0.2% of the investigated dwelling stock. However, occurrences of more than 1000 Bq/m 3 cannot be excluded completely. A rather clear increase of the number of dwellings with radon concentrations greater than 400 and 1000 Bq/m 3 has been found in areas with soil gas radon concentration >100 kBq/m 3 (about 6% of the area).

Radon Concentrations in Buildings in the North-eastern Region of Poland

The paper presents the results of radon concentration measurements in dwelling houses in Poland’s northeastern region. The investigations were carried out using PICO-RAD carbon detectors. The results from 412 measurements ranged from 4 to 1300 Bq m −3. In the inhabited parts of houses the respective values were: arithmetical mean =25 Bq m −3, geometrical mean =17 Bq m −3 and median =16 Bq m −3. In the basements these values were 76, 36 and 32 Bq m −3, respectively. By taking into account the population density and the mean radon concentration in the inhabited part of the houses, the mean annual dose equivalent from radon was estimated to be 0·63 mSv for the northeastern region of Poland.

Influence of Shallow Mine-Workings on the Radon Concentrations in Houses: A Problem of Old Mining Regions

Abstract In some regions of the German New Federal Lands, residues from early mining characterise the radiological situation and can also influence the radon concentration in buildings. Construction on waste rock with increased radium concentration, the use of waste rock as building material and construction above shallow mine shafts and adits are important in this connection. In Saxony, for instance, one has to reckon with probably hundreds of buildings that may be influenced by radon from shallow mine workings. Very short-term changes of radon concentrations in buildings over several orders of magnitude was well as their close temporal correlation with the underground airflow clearly indicate influences from underground. In Schneeberg and Schlema, fluctuations of radon concentration in buildings of several 10,000 Bq.m-3 within one hour were observed. In Schneeberg, the old mine was ventilated artificially by installing a ventilator with an output volume of 500 m3min-1. Thus the radon concentration in buildings of the central city area has been reduced. In Schlema, the radon rich shafts of early mining are ventilated at present by the still active ventilation system of the suspended uranium ore mining. In 1992, during the first six months, 4.5 x 109 m3 of mine air with a radon activity of 6.3 x 1014Bq were extracted from the mine. If the mine ventilators are switched off, radon concentration in buildings over mine shaft increases sharply by two orders of magnitude.

Influence of Shallow Mine-Workings on the Radon Concentrations in Houses: A Problem of Old Mining Regions

In some regions of the German New Federal Lands, residues from early mining characterise the radiological situation and can also influence the radon concentration in buildings. Construction on waste rock with increased radium concentration, the use of waste rock as building material and construction above shallow mine shafts and adits are important in this connection. In Saxony, for instance, one has to reckon with probably hundreds of buildings that may be influenced by radon from shallow mine workings. Very short-term changes of radon concentrations in buildings over several orders of magnitude was well as their close temporal correlation with the underground airflow clearly indicate influences from underground. In Schneeberg and Schlema, fluctuations of radon concentration in buildings of several 10,000 Bq.m-3 within one hour were observed. In Schneeberg, the old mine was ventilated artificially by installing a ventilator with an output volume of 500 m3min-1. Thus the radon concentration in buildings of the central city area has been reduced. In Schlema, the radon rich shafts of early mining are ventilated at present by the still active ventilation system of the suspended uranium ore mining. In 1992, during the first six months, 4.5 x 109 m3 of mine air with a radon activity of 6.3 x 1014Bq were extracted from the mine. If the mine ventilators are switched off, radon concentration in buildings over mine shaft increases sharply by two orders of magnitude.

Radon in Eastern German Houses - Surveys and Outcomes

Abstract Comprehensive systematic investigations of the problem of radon in Eastern German houses have been launched by the Federal Office for Radiation Protection after German unification. Results obtained so far show the dominant contribution of the ground below to enhanced radon concentrations in buildings. Granitic formations near the surface give rise to extended high median values of the frequency distribution. Extremely high concentrations are observed in ore mining regions where direct connections exist between buildings and mining relics in the ground, e.g. uranium bearing waste rock or near-surface drives. Mining and building type peculiarities require specific solutions of remediation which are studied in a federal-promoted project. Outside areas determined geologically or by mining the frequency distribution of radon in Eastern German houses is expected to analogous to Western Germany so that, in Germany as a whole, the percentage of houses with radon concentrations above the normal range as defined by the German Radiation Protection Commission will probably be increased only moderately.

The Use of Computed Radon Entry Rates to Understand Radon Concentration in Buildings

The central role played by basement depressurization in drawing radon-contaminated soil gas into a structure has been demonstrated by calculating the radon entry rate from radon concentration and air infiltration measurements at different levels of basement depressurization in a single-family research house. The radon entry rate is found to be a linear function of basement depressurization in this house which indicates that the flow of soil gas into the structure is laminar. The radon entry rates calculated before and after using a mitigation procedure is shown to provide a better measure of the mitigation efficacy than the standard before and after mitigation radon measurements in a research house. In addition, an analysis of the possible flow characteristics of soil gas and uncontaminated air into a basement indicates that any attempt to predict long-term average radon exposure from short-term screening measurements will only be possible under severely restricted conditions.