Average Radon Concentration Research Articles

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.

Indoor and outdoor 222Rn and 220Rn and their progeny levels surrounding Bayan Obo mine, China

Abstract More than half of the total natural ionizing radiation dose received by the human population is caused by radon and thoron (Rn and Tn) and their progeny. To estimate the level of radiation due to radon and thoron and their progeny, an investigation was conducted in a residential area near the world’s largest open-pit mine of Bayan Obo in Inner Mongolia, China. The concentration of Rn, Tn, and their decay products in air and soil were studied by using AlphaGUARD, RAD7, and ERS-RDM-2S for a discrete period of time in three different locations. The average indoor concentration of radon and thoron was 62.6 ± 44.6 Bq/m3 and 108.3 ± 94.5 Bq/m3 respectively, and the outdoor concentration was 12.9 ± 6.3 Bq/m3 and 55.8 ± 18.5 Bq/m3, respectively. Relatively high concentrations were recorded in the area near to the mine, with a significant increasing trend observed in indoor thoron concentration. A prominent hotspot in thoron concentration was found in a single-story house with values 747 ± 150 Bq/m3. The equilibrium equivalent thoron concentration (EECTn) varies from 0.48 Bq/m3 to 2.36 Bq/m3 with an arithmetic mean of 1.37 ± 0.64 Bq/m3, and comparatively higher than EECRn. Concluding that the mining activity at Bayan Obo mine is significantly increasing the level of indoor thoron and its progeny in surroundings. It is suggested to further systematically investigate the indoor Rn and Tn progeny concentrations in the residential dwellings of the Bayan Obo mining area, and 232Th content of the building materials, to provide a basis for calculating the radiation dose.

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.

Simultaneous measurements of radon, thoron and their progeny for inhalation dose assessment in indoors of Srinagar, J&K, India

A variety of toxins are known to affect indoor air quality, thereby affecting the health of the inhabitants of that region. One such natural contaminant is radon, which is a dense, colourless, odourless and inert gas. As per BEIR-VI report (Chauhan and Chauhan in J Environ Radioact, 2015. https://doi.org/10.1016/j.jenvrad.2015.03.009), Radon alone contributes to more than 50% of the total natural background radiation and is the second leading element causing lung cancer after smoking. Therefore, its quantification is vital to assess any risk to human health. In order to assess health risks, a recently developed LR-115 detector based technique was employed for time-integrated passive measurements of radon, thoron and their progeny concentrations. The annual average radon concentration was found to be 35.6 Bq m−3 and thus lies well below the global average of 40 Bq m−3. However, thoron concentration exceeded the global average value of 10 Bq m−3.

Radon concentration potential in Bibala municipality water: Consequences for public consumption

The primary motivation for this work is the evaluation of the radon concentration in drinking water for human consumption in Bibala, a municipality in Angola, where granitic rocks are common, and contain a high concentration of uranium that can be mobilized in underground water. Radon is the largest contributor of radioactive pollution in underground water. Its concentration in water, represents a public health risk due to the fact that the gas can easily escape into the air, adding to the total indoor concentration of radon. On the other hand, ingestion of water with a high radon concentration represents an additional risk to the stomach. Measurements of radon concentration, in Bibala municipality's water, were performed by collecting 3 samples from each of the 27 water wells of diverse depth, with DURRIDGEs' RAD7 and the average radon concentration are identified by S1 to S27. Measured concentrations are in the range from 5.3 ± 0.6 to 42 ± 5 Bq L−1, with 67% of the recovered samples presenting values over 11 BqL−1, the USEPA recommended level and all samples present radon concentration below 100 Bq L−1, the WHO recommendation level.

INDOOR RADON AND THORON IN THE VICINITY OF PROPOSED URANIUM MINING SITE: A CASE STUDY AT DASARLAPALLY VILLAGE, TELANGANA STATE, INDIA

Studies are being conducted for the past few decades in and around the uranium mining sites across the globe to identify environmental nuclear radiation risk to the common public. The area near Dasarlapally village was identified for uranium exploration by the AMDER, Hyderabad. The present study was carried out to measure the indoor radon and thoron activity concentrations in the dwellings of Dasarlapally village. For this purpose different types of dwellings were chosen randomly across the village. The measured annual average concentration of radon and thoron in dwellings were found to be 141±42 and 139±77 Bqm-3, respectively, and the calculated annual effective inhalation dose due to radon was determined to be 3.5mSv. Seasonal variation and diurnal variation of radon and thoron activity concentration were investigated. The variation of radon and thoron activity concentration in different types of dwellings was also studied, and the variation was found to be statistically insignificant. The uncertainty propagated in the effective inhalation dose due to thoron was discussed.

Radon survey in office room and effective dose estimation for staff

This study aims to: (1) Acquire the radon level in closed office rooms, providing radon exposure data for preliminary health risk assessment of office-working population. (2) Pre-analyze the relationship between radon concentration and indoor temperature, relative humidity. (3) Estimate seasonal, annual and total radon effective dose for ordinary office-working population. The results show that the 24-h or 8-h average radon concentrations in closed office rooms were about 32.0 Bq/m3 and 29.5 Bq/m3 during detection period, and the estimated effective doses in office rooms calculated by using 24-h and 8-h average radon concentrations were all far below that in residential environment.

Human Health Risk Assessment for Exposure to Radioactive Radon with Due Regard for Its Nanodispersed Decay Products

A technique was designed to assess the human health risk associated with exposure to radioactive radon. As a focus, a dose–effect relationship model was developed on the basis of international and first-hand experience. The model suggests a multiplicative dependence on the probability of spontaneous lung cancer and takes account of the fact that radiation effects on the lungs are exerted by the radon decay daughter products entering the lungs in a nanodispersed form. The effects of radon are already present in the statistics of spontaneous lung cancer, and the risk of death from spontaneous and radiation-induced lung cancer depends strongly on the smoking status. A test calculation of the radon-associated risk was performed for a region of the Russian Federation and showed that radon may substantially contribute to mortality from lung cancer in areas with relatively high radon concentrations in the ambient air. Exposure to radon at an annual average radon concentration comparable with the standard level for new buildings under construction (200 Bq/m3) increases the risk of death from lung cancer by 20%. The method is suitable for assessing the health risk associated with exposure to radon for miners and the general population.

Thermal Performance and Comfort Condition Analysis in a Vernacular Building with a Glazed Balcony

The increase in global environmental problems requires more environmentally efficient construction. Vernacular passive strategies can play an important role in helping reducing energy use and CO2 emissions related to buildings. This paper studies the use of glazed balconies in the North of Portugal as a strategy to capture solar gains and reduce heat losses. The purpose is understanding thermal performance and comfort conditions provided by this passive heating strategy. The methodology includes objective (short and long-term monitoring), to evaluate the different parameters affecting thermal comfort and air quality, and subjective assessments to assess occupants’ perception regarding thermal sensation. The results show that the use of glazed balconies as a passive heating strategy in a climate with cold winters is viable. During the mid-seasons, the rooms with balcony have adequate comfort conditions. In the heating season, it is possible to achieve comfort conditions in sunny days while in the cooling season there is a risk of overheating. Regarding indoor air quality, carbon dioxide concentrations were low, but the average radon concentration measured was high when the building was unoccupied, rapidly decreasing to acceptable values, during occupation periods when a minimum ventilation rate was promoted. Occupants’ actions were essential to improving building behavior.

A Study on Distribution and Characteristics of Radon Concentration in Metro Line 1 in Busan

Objective : Adverse health effects of Radon with a particular focus on indoor environment has been outlined. Most of the metro stations and platforms are situated under the ground where relatively enhanced concentration of radon has been observed.Method : On-line measurements of indoor Radon have been made in Metro Line 1 in Busan using RAD-7.Results and Discussion : The average concentration of Radon was 8.9 Bq/m<sup>3</sup> (n=40). In general, a positive relation was shown between the level of radon and the depth of station. Slightly enhanced radon concentrations were observed between 0 a.m. ~ 5 a.m. when the station is closed under the non-operation of ventilation system. Interestingly, the negative relation was seen between the radon revel and temperature.Conclusions : Relatively low levels of indoor radon has been observed in Metro Line 1 in Busan, which may be associated with geographical location of non-granite regions.

Problem of radon exposure in energy-efficient buildings: a review

The paper presents an overview of the international scientific and technical publications on a problem of radon accumulation in new energy efficient buildings and in houses reconstructed according to requirements of energy saving. Energy efficiency is an important requirement of the environmentally sustainable development. Housing and communal services have significant potential for energy saving. In Russia, the construction of highest energy efficiency classes buildings occurs at an accelerated rate and reached 75% of all multiapartment houses built in 2017. The applying of modern technologies that reduce heat loss is accompanied by a decrease in the air exchange rate, which leads to deterioration of indoor air quality, in particular, the accumulation of radon. In the international literature, there are examples of the several times growth of radon concentration after the reconstruction of the building, the average radon concentration in retrofitted buildings increased by 22–120%. In new houses built to meet energy saving requirements, there can also be a significant increase in radon concentration compared to low-energy efficiency classes houses. Excess of sanitary and hygienic norms was found in some countries, including Russia. Radon exposure of dwellers of energy-efficient buildings is largely determined by the living habits. Based on the review data, it can be assumed that the average level of Russian population exposure to radon can increase under conditions of intensive construction of energy-efficient buildings.

Radon concentration assessment in bank cellars in three Nigerian cities

Cellar workplaces are considered as confined environment with challenging indoor air quality having higher than normal pollutants particularly that of soil gas origin. Radon, a major soil gas, infiltrates and accumulates within indoor spaces and becomes harmful in the absence of ventilation. Radon level in bank basements (cellars) in Ilorin, Lagos and Akure have been sampled and analysed in this study. In Nigeria, most workers in basements are unaware of radon, and there is limited documented research on its health hazards. The survey parameters of radon concentrations were floor types, geographical locations and the influence of atmospheric conditions. Corentium monitor, a continuous, digital radon monitor, temperature meters and Prologue wireless weather station were used for the experiments. Annual average indoor radon concentration for the survey period was 23 Bq/m 3 . The calculated mean annual effective doses in basements and different floors were below the recommended ICTR level of 3 mSv/y. Keywords: Indoor air quality, Pollutants, Radon, Ventilation

Predicting residential radon concentrations in Finland: Model development, validation, and application to childhood leukemia.

Objectives Inhaled radon gas is a known alpha-emitting carcinogen linked especially to lung cancer. Studies on higher concentrations of indoor radon and childhood leukemia have conflicting but largely negative results. In this study, we aimed to create a sophisticated statistical model to predict indoor radon concentrations and apply it to a Finnish childhood leukemia case-control dataset. Methods Prediction was based on ~80 000 indoor radon measurements, which were linked to national registries for potential indoor radon predictors based on the literature. In modelling, we used classical methods, random forests and deep neural networks. We had 1093 cases and 3279 controls from a nationwide case-control study. We estimated odds ratio (OR) for childhood leukemia using conditional logistic regression adjusted for potential confounders. Results The r 2of the final log-linear model was 0.21 for houses and 0.20 for apartments. Using random forest method, we were able to obtain slightly better fit for both houses (r 2= 0.28) and apartments (r 2= 0.23). In a risk analysis based on the case-control data with log-linear model, we observed a non-significant (P=0.54) increase with predicted radon concentrations [OR for the 2 ndquartile 1.08, 95% confidence interval (CI) 0.77-1.50, OR 1.10 with 95% CI 0.79-1.53 for the 3 rd, and 1.29 with 95% CI 0.93-1.77 for the highest quartile]. Conclusions Our modelling and the previously published models performed similarly but involves major uncertainties, and the results should be interpreted with caution. We observed a slight non-significant increase in risk of childhood leukemia related to higher average indoor radon concentrations.

INDOOR RADON CONCENTRATION AND RISK ASSESSMENT IN SOME DWELLINGS OF OBUASI, MINING TOWN.

222Rn concentration indoors was measured in 40 dwellings in the Obuasi municipality, a gold-mining town in the Ashanti Region of Ghana using the LR 115 type II strippable detectors for the two major seasons in Ghana, rainy and dry. The detectors were placed in the bed rooms of dwellers for 6months each. Average indoor radon concentration varied from 63.9 to 364.9Bqm-3 with a mean of 152.2±10.9Bqm-3 in the rainy season and 26.1-119.0 Bqm-3 with a mean of 50.5±3.9 Bqm-3 in the dry season. The effective dose of 3.90±0.3mSvy-1 for the rainy season and for the dry season, effective dose of 0.6mSvy-1 were recorded. The seasonal variation of 222Rn concentration indoors showed higher values in the rainy season than the dry season. A dependence was observed between the type of building materials used in building and the indoor radon level.

RADON, THORON AND THEIR PROGENY DISTRIBUTION AND ESTIMATION OF ANNUAL EFFECTIVE DOSE AND EXCESS LIFETIME CANCER RISK IN PANATHADY, KASARAGOD DISTRICT, KERALA.

Radon and thoron are natural radioactive gases that tend to accumulate in the indoor environment and one of their major health implications is the ability to cause lung cancer. Present study comprises the quantification of radon and thoron activity concentrations and measurement of gamma exposure rates in different types of dwellings from the endosulfan-affected area, Panathady, Kasaragod district, Kerala. It is observed that, residents of this area were more prone to various diseases and health problems including cancer. The LR-115 type II solid state nuclear track detectors with single entry pin-hole based dosemeters have been used for the measurement of 222Radon and 220Rn activity concentrations. The assessment of radiological parameters such as annual effective doses and excess lifetime cancer risk has also been done in order to understand the dose level and the associated risk. The estimated values have been compared with the limit recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and International Commission on Radiological Protection (ICRP). The average indoor radon and thoron activity concentrations observed in these dwellings were 134±30 and 111±28Bqm-3, respectively. The estimated activity concentrations, effective doses, etc. are found to be within the recommended level by the UNSCEAR or ICRP.

Radon (222Rn) concentrations in the touristic Jumandy cave in the Amazon region of Ecuador.

ABSTRACTThis work consists of the detection and quantification of the concentration levels of radioactive gas radon-222 (222Rn) of natural origin, as well as the determination of the critical points and the estimation of the effective dose absorbed by the tourists and guides inside the Jumandy cavern in Napo, Ecuador. According to the feasibility map of uranium of Ecuador, the study area is located in one of the top-priority areas for obtaining uranium, suggesting possible radioactivity in this unstudied region. The measurements were carried out from July to October of 2017, in three different monitoring points inside the cavern. The average radon concentrations measured in the cavern exceeded the maximum recommended environmental level by a factor of 28, and the effective dose absorbed by the guides exceeded the recommended maximum by a f actor of 10. Meteorological parameters such as temperature and relative humidity have an impact on the 222Rn concentrations in different parts of the cave.

Radiological impact assessment of soil and groundwater of Himalayan regions in Uttarakhand, India

In this study, we present the results of measurements and radiological impact of natural radioactivity in soil and groundwater of the Himalayan region in the Uttarakhand State of India. The concentrations of primordial radionuclides (226Ra, 232Th and 40K) in soil samples of the study area were determined using gamma-ray spectrometry by employing the NaI(Tl) detector. The concentrations of radon and uranium were also measured in potable groundwater samples using RAD7 and Inductively Coupled Plasma Mass Spectrometry (ICPMS) techniques, respectively. The average specific activities of 226Ra (116 Bq kg−1), 232Th (137 Bq kg−1) and 40K (735 Bq kg−1) in soil were found considerably higher than the corresponding global average values. The average concentrations of radon (35 Bq l−1) and uranium (1.3 µg l−1) in potable groundwater were found well within the safe limits recommended by the World Health Organization. The effects of natural radioactivity in soil and groundwater are discussed in terms of different risk assessment parameters and dose quantities.

Studies on Indoor and Outdoor Radon/Thoron Concentration and Estimation of Radiological Parameters from Gamma Dose Rates along the Coastal Regions of Trivandrum and Kollam Districts, Kerala, India

The indoor and outdoor radon and thoron and γ-exposure rates were measured in different types of houses in selected locations along coastal regions of Trivandrum and Kollam districts, Kerala, which are reported as high-background-radiation areas (HBRAs). The dose to lungs due to indoor radon, the annual effective dose due to radon and thoron, and the γ-dose rates were estimated. The average concentrations of radon and thoron are well within the action level recommended by ICRP. The average effective doses are also within the safe limit (3-10 mSv year−1). The average value of excess lifetime cancer risk (ELCR) is 6.8 × 10−3, being higher than the world-average value of 0.29 × 10−3.

Radon Monitoring: Pathway to Environmental Sustainability

One important dimension of environmental sustainability is the need to maintain ecosystem services critical to the human population. These services include providing food, shelter, and construction materials. It has been discovered that construction materials contain certain amount of radon. So humans are most susceptible to radon related problems because we spend at least one third of the day indoor. Maintaining environmental sustainability is crucial to attaining the Sustainable Development Goals (SDGs). Radon monitoring is essential in determining the actual level of exposure in buildings. The indoor radon concentration in Covenant University Centre for Research Innovation and Development (CUCRID) has been studied using RAD7 radon detector machine. The result fro the study revealed that the average cumulative radon concentration for the building is 16.15 Bqm−3 which is lower than the permissible recommended level. Hence, it can be concluded that the radon level in CUCRID building does not pose any risk level to the occupants therefore the environment is safe for workers.

Measurement of radon in soils of Lima City - Peru during the period 2016-2017

Lima City is situated on alluvial fan deposits of rivers flowing through geological formations that contain different levels of uranium. In this paper, a study is made on the average spatial and temporal behavior of radon gas in soils of Lima City. Radon concentration was determined using the LR-115 type 2 track detector during 36 periods, of 14 days each, in twenty holes distributed in the fifteen districts of Lima City. Radon concentration in soil pores ranged from 0.1 to 64.3 kBq/m3 with an average value of 5.6 kBq/m3. The average radon concentration in soil gas was about two times lower in winter than in the other seasons. High radon values during October/November 2017 were related to the earthquakes perceived in Lima City in that period. The highest radon concentrations were found in areas of alluvial deposits whose parental material has been removed from the Quilmaná and Huarangal volcanics by the Chillón and Huaycoloro Rivers. Soil gas radon concentrations were even higher in areas closer to volcanic and less distant from rivers. During the period of maximum flooding of the Chillón, Rímac and Lurín rivers, due to the natural phenomenon “El Niño Costero”, anomalous high soil radon concentrations were observed in most of the measurement sites located near rivers. These high radon values were associated with ground vibrations caused by rock and debris avalanches in rivers and creeks.