Measurements Of Indoor Radon Concentrations Research Articles

Radon survey in Chelyabinsk Oblast, Russia, in 2008–2011. Analysis of spatial variability of indoor radon concentration

An extensive radon survey was conducted in 2008-2011 in the framework of the Federal target program on the territory of 29 districts of Chelyabinsk Oblast. SSNTDs were used to measure indoor radon concentrations in public buildings, dwellings and industrial buildings. The results are stored in the database “Radon” owned by Research and Technical Center of Radiation-Chemical Safety and Hygiene of Federal Medical-Biological Agency. The paper presents the results of the analysis of spatial variability of indoor radon concentration and the relationship of this value with a set of geological predictors of radon potential of the territory integrated into a map of ecological and radiogeochemical zones. The results show that in all districts and the whole Chelyabinsk Oblast radon concentrations conform to a lognormal distribution, but in ten districts log-logistic distribution fits the data slightly better. Nevertheless, relative difference between the median values of indoor radon concentration calculated from the two fitted distributions yields zero. The results show that dose assessment based on the arithmetic means could lead to an overestimation of the doses from radon in 1.4 times on average compared to that based on the medians. The median value does not exceed 400 Bq/m3 in any of the surveyed territories and the 95th percentile lies between 96 and 1274 Bq/m3. The fraction of indoor radon concentrations above 400 Bq/m3 expected from the fitted distribution lies between less than 0.1 and 26.8%. The highest values of this fraction were obtained for the Sosnovsky, Kaslinsky, Bredinsky districts and the Miassky urban district (except for the city of Miass). A map of ecological and radiogeochemical zones in Chelyabinsk Oblast was released in 1993-1995 and it was based on a set of geological predictors of radon potential of the territory. We analyzed the relationship of these zones with the results of the radon survey. One-way ANOVA on ranks with the Bonferroni correction showed that there is no statistically significant difference at the 95% confidence level amongst the medians of indoor radon concentration on basement, ground and first floors in settlements, which are located on the territory of three of four of these zones and outside of the territory of all zones. In the fourth zone the median was even two times lower than outside of the zones. These results lead to the conclusion that the possibility of using this map as a map of radon-prone areas is very doubtful. Each datapoint stored in the “Radon” database has a number of additional properties, which allows analyzing other types of indoor radon concentration variability such as seasonal or floor-to-floor. It is expected that later this dataset could be used for estimating regional seasonal correction factors.

A study on correlation of measured indoor radon concentrations by RadonEye and RS9A in multi-use facilities

A study on correlation of measured indoor radon concentrations by RadonEye and RS9A in multi-use facilities

Study of baseline radon levels in the context of a shale gas development

This study reports the results from continuous measurement of indoor and outdoor radon concentrations in the area surrounding an unconventional shale gas exploration site in North Yorkshire, England, prior to the commencement of hydraulic fracturing. Public Health England has monitored the baseline radon levels in homes and in outdoor air in the Vale of Pickering since 2015. The statistical analysis presented here includes three full years (November 2015‐ –December 2018) of indoor and four and half years (October 2015 – April 2019) of outdoor radon measurements.Stratified sampling was used to select 171 dwellings in four areas, with two different radon potential. Statistical analysis confirms that homes in Kirby Misperton and Little Barugh and those in Yedingham are situated in areas with low radon potential, as was predicted by the UK radon potential map. On the other hand, both Pickering and Malton are confirmed as radon Affected Areas.Radon was measured continuously in the outdoor air using a newly developed outdoor kit containing passive radon detectors. The monitoring points were set up at 36 locations in the same local areas as those selected for the indoor monitoring. The results from statistical analysis show that outdoor radon had a different seasonality pattern to indoor radon. The monitoring of outdoor radon levels over the four and half years indicates a year-to-year variation in outdoor radon concentrations with levels fluctuating between 3 and 9 Bq m−3.There was a very good agreement between long-term average radon concentrations measured using passive detectors and using an active AlphaGUARD monitor.

Measurement of Indoor Radon Concentration in the Hunza Valley of Karakoram Ranges Northern Pakistan

Among the lofty mountains of Karakoram ranges in Northern Pakistan, lies the Hunza Valley, home of a community of disease and cancer free people said to survive longer with life expectancy of around 100 years, whereas the average life expectancy in Pakistan is 67 years. Indoor radon measurements were carried out in the five villages of Hunza-Valley. The average Radon concentration levels were found to be 52.97 ± 25.25, 43.49 ± 16.04, 34.15 ± 17.93, 30.38 ± 10.82 and 30.80 ± 19.48 Bqm−3 respectively in Hassianabad, Altit, Murtazabad, Karimabad and Aliabad. The annual effective dose was calculated as 0.68 ± 0.32, 0.5 ± 0.20, 0.44 ± 0.23, 0.4 ± 0.14 and 0.25 ± 0.06 mSvy−1 in the above mentioned five villages. The radon concentration levels, are much below the action level recommended by the ICRP (300 Bqm−3), USEPA (150 Bqm−3), and WHO (300 Bqm−3). Radiation hormesis that the low doses of ionizing radiation are beneficial, stimulating the activation of repair mechanisms that protect against diseases, is the possible reason for their long life and absence of diseases and cancer from the region.

Indoor Radon Measurements in Finnish Daycare Centers and Schools-Enforcement of the Radiation Act.

Background: Indoor radon exposure is the second leading cause of lung cancer. Finnish radiation legislation obligates employers to measure indoor radon concentrations in workplaces, including schools and daycare centers, if they are in radon prone areas. Surveillance campaigns were conducted to ensure that the required radon measurements were performed and to gain knowledge on current indoor radon levels in daycare centers and schools. Methods: Daycare centers located in the high-radon risk municipalities were identified. Schools where indoor radon level measurements were obligatory but not performed, were identified. Results: Indoor radon measurements were performed in 633 daycare centers where the mean radon concentration was 86 Bq/m3 and the median 40 Bq/m3. The radon level was greater than 300 Bq/m3 in 8% (n = 49) of daycare centers. The radon measurements were performed in 1176 schools, which is 95% of the schools to be measured. The mean radon concentration was 82 Bq/m3 and the median 41 Bq/m3. The radon levels were greater than 300 Bq/m3 in 14% (n = 169) of the schools. Conclusions: The systematic surveillance campaigns by the radiation protection authority were very efficient in order to ensure that the measurements are performed in schools and daycare centers. The campaigns also reduced the radon exposure of employees, children, and adolescents, where necessary.

Short-Term Measurement of Indoor Radon Concentration in Northern Croatia

(1) Background: Radon concentrations in the environment are generally very low. However, radon concentrations can be high indoors and can cause some serious health issues. The main source of indoor radon (homes, buildings and other residential objects) can be soil under the house, while other sources can be construction materials, groundwater and natural gas. Radon accumulates mainly in the lower levels of the buildings (especially low-ventilated underground levels and basements). (2) Methods: in this paper, we have measured the indoor radon concentrations at 15 locations in various objects (basements and ground floor/1st floor rooms) in the area of northern Croatia. (3) Results: the results show a higher concentration of radon in the basement area in comparison to values measured in the ground floor and first-floor rooms. The arithmetic mean (AM) and geometric mean (GM) of basement rooms were 70.9 ± 38.8 Bq/m3 and 61.2 ± 2.2 Bq/m3 compared to ground floor and first-floor rooms 42.5 ± 30.8 Bq/m3 and 32.8 ± 2.9 Bq/m3, respectively. (4) Conclusions: results obtained (AM and GM values) are within the maximal allowed values (300 Bq/m3) according to the Euroatom Directive. However, there are periods when maximum radon concentration exceeds 300 Bq/m3. Indoor radon concentrations vary with the occupancy of the rooms and it is evident that the ventilation has significant effect on the reduction of concentration.

Occupational and residential radon exposure: a study in North-Western Greece

Measurements of indoor radon concentrations were performed in 44 workplaces and 87 dwellings in the region of Epirus, north-western Greece, using electret and alpha-track detectors. Radon concentrations followed a log-normal distribution with an arithmetic mean of 92 Bq/m3 in workplaces and 86 Bq/m3 in dwellings. A mean annual effective dose of 0.64 and 1.63 mSv/y was estimated for occupational and residential exposure, respectively. The reported data contribute to the assessment of radon distribution and dose estimate at the national level.

Concentration of Radon in Indoor Air in Lalibela, Ethiopia

The second largest cause of lung cancer is related to radon (²²²Rn) and its progenies in our environment. Building materials, such as concrete, contribute to the production of radon gas through the natural decay of ²³⁸U from its constituents. This Radon has been recognized as one of the major contributor to the natural radiation and health hazards in the human dwellings. Even lung cancer is expected if it is present in enhanced levels beyond maximum permissible (acceptable) limit. This thesis reports the measurements of indoor radon concentration in the Lalibela dwellings of the Amhara region in Northern Ethiopia using the cellulose nitrate (LR-115 type-II) plastic track detectors. Eleven cellulose nitrate films (LR-115 SSNTD) were distributed over the study area dwellings according to the fraction of the population. The exposure time was started from February 21/2013 and lasted for 90 days. It is found that the values of radon concentration vary from 52.45 to 353.95 Bqm^-3 with the average value of 140.64 Bqm^-3. The effective dose rates have been calculated and found to vary from 1.38 to 9.34 mSvy^-1 with over all mean value of 3.71 mSvy^-1. It is also found that mud houses (houses use unbaked bricks) have relatively lower indoor radon as compared to the houses which are made of the baked bricks and cement.

Occupational and residential radon exposure: a study in North-Western Greece

Measurements of indoor radon concentrations were performed in 44 workplaces and 87 dwellings in the region of Epirus, north-western Greece, using electret and alpha-track detectors. Radon concentrations followed a log-normal distribution with an arithmetic mean of 92 Bq/m3 in workplaces and 86 Bq/m3 in dwellings. A mean annual effective dose of 0.64 and 1.63 mSv/y was estimated for occupational and residential exposure, respectively. The reported data contribute to the assessment of radon distribution and dose estimate at the national level.

Indoor Radon Concentrations Measurements for Selected Dwellings in Some Baghdad Districts – Iraq

In this work, measurements of indoor radon concentrations were completed for selecteddwellings in Baghdad governorate using DURRIDGE RAD7 detector. The spectra measuredby this detector demonstrated that, the radon concentrations were changed from 89 Bq/m 3(Hay Ur district) to 191 Bq/m 3 (Al-Mansour district) with an average value of 123.3±24.3Bq/m 3 which is below the recommended range (200-300 Bq/m 3 ) given by (ICRP, 2009). Allother studied parameters such as EP, PAEC, AED and CPPP their values were less than orcorresponding to the allowed worldwide average values.

County-level indoor radon concentration mapping and uncertainty assessment in South Korea using geostatistical simulation and environmental factors

This paper presents a geostatistical simulation approach to not only map the county-level indoor radon concentration (IRC) distributions in South Korea, but also quantify the uncertainty that can be used as decision-supporting information. For county-level IRC mapping in South Korea, environmental factors including geology, radium concentration in surface soil, gravel content in subsoil, and fault line density, which are known to be associated with the source and migration of radon gas, were incorporated into IRC measurements using multi-Gaussian kriging with local means. These four environmental factors could account for about 36% of the variability of noise-filtered IRCs, implying that regional variations of IRCs were affected by these factors. Sequential Gaussian simulation was then applied to generate alternative realizations of county-level IRC distributions. By summarizing the multiple simulation results, we identified some counties that lay on the great limestone series showed elevated IRCs. In addition, there were some counties in which the proportion of grids exceeding the recommended level was high but the uncertainty was also large according to the analysis of several uncertainty measures, which indicates that additional sampling is required for these counties. From the local cluster analysis in conjunction with simulation results, we found that the counties with higher levels of IRC belonged to the statistically significant clusters of high values, and these counties should be the prime targets for radon management and in-depth survey. The geographical distributions of IRC and uncertainty measures presented in this study provide guidance for effective radon management if they are consistently combined with both future IRC measurements and a geogenic radon potential map.

Measurement of Indoor Radon Concentration in Bahraich and Barabanki District of Eastern U.P. using LR-115 Type II Plastic Track Detector (SSNTDS)

Measurement of Indoor Radon Concentration in Bahraich and Barabanki District of Eastern U.P. using LR-115 Type II Plastic Track Detector (SSNTDS)

Measurement of indoor radon concentration and annual effective dose estimation for a university campus in Istanbul

Radiation is a natural part of the environment that people interact continuously, and radon is one of the most important sources because of its abundance and mobility. Due to gas form, radon can reach and accumulate in living places easily. Inhalation of radon and its progenies is an important risk factor for health hazards. Accurate measurement of radon levels is quite essential for the dose evaluation of radon exposure in buildings. In this study, radon activity measurements have been performed by using AlphaGUARD portable radon detector at several locations in Akfirat campus of Istanbul Okan University. Annual effective doses were calculated by using ICRP regulations for various exposure periods.

Indoor risk assessment of radon gas in the science college buildings-University of Mustansiriyah using RAD-7 detector

In the present work, a set of indoor Radon concentration measurements was carried out in a number of rooms and buildings of Science College in the University of Mustansiriyah for the first time in Iraq using RAD-7 detector which is an active method for short time measuring compared with the passive method in solid state nuclear track detectors (SSNTD's). The results show that, the Radon concentrations values vary from 9.85±1.7 Bq.m-3 to 94.21±34.7 Bq.m-3 with an average value 53.64±26 Bq.m-3 which is lower than the recommended action level 200-300 Bq/m3 [ICRP, 2009].The values of the annual effective dose (A.E.D) vary from 0.25 mSv/y to 2.38 mSv/y, with an average value 1.46±0.67 mSv/y which is lower than the recommended the range 3-10 mSv/y [ICRP, 1993]. While the values of lung cancer cases per year per million person vary from 4.50 per million person to 42.84 per million person with an average value 24.35±12 per million person which is lower than the recommended range 170-230 per million person [ICRP, 1993].The values of the potential alpha energy concentration were found to vary from 10.18 mWL to 1.06 mWL, with an average value 5.79±2.8 mWL which is lower than the recommended value of 53.33 mWL given by [UNSCEAR, 1993].

Measurement of Indoor Radon Concentration in Some Selected Offices of Adigrat University, Tigray Region, Ethiopia

Radon is an inert radioactive gas. A long term exposure to high concentration of radon causes lung cancer. Taking this into account, an investigation in some offices of Adigrat Universityhas been made to estimate the radon concentrations and to determine the health risk of the workers in the community. In the present study, Solid State Nuclear Track Detectors (LR-115 type II) has been used to measure the emission of radon from 12 offices for a period of 3 months. After an exposure time of 3 months, films were removed from each office andtaken for etching. After the etching, films were washed with distilled water and allowed to dry for 1day. Finally, alpha tracks were counted using an optical microscope at magnification power of 400X. Results obtained in the present study show that the value of concentration of radon ranges from 171.31 Bq.m−3 to 394.05 Bq.m−3 with mean concentration273.79 Bq.m−3 and standard deviation of 79.7Bq.m−3 and the inhalation dose rate varies from a minimum of 1.54 mSv.y−1 to a maximum of 3.55 mSv.y−1 with an average of 2.46 mSv.y−1 and standard deviation of 0.72 mSv.y−1. Even though, radon concentration levels were found to be higher the inhalation dose rate is safe within recommended limits

Measurement of Indoor Radon Concentration in Dalat area

A significant contribution to natural exposure of humans is radon gas, which emanates from the soil and may concentrate in dwellings. The level of radon exposure varies around the globe, but limited data are available on the daily variations of indoor radon concentrations. In this study, indoor radon measurements were performed continuously within one week at six different places in Dalat, Vietnam using the real time Smart Radon Detector Radon Eye+. The indoor radon behavior in a day follows a sine pattern, with peak values in the early morning and lowest values in the late afternoon. There are also some fluctuations at specific times due to different weather conditions. Indoor radon concentrations in the Dalat regions were found to exceed the recommended guidelines and thresholds; excessive radon levels warranting health concern were found (150.7-340.0 Bq/m3). Some corrective actions to reduce indoor radon concentrations were recommended. Annual effective doses on different age categories were also calculated.

Estimation of Seasonal Correction Factors for Indoor Radon Concentrations in Korea.

Long-term exposure to high radon concentration exerts pathological effects and elicits changes in respiratory function, increasing an individual’s risk of developing lung cancer. In health risk assessment of indoor radon, consideration of long-term exposure thereto is necessary to identify a relationship between indoor radon exposure and lung cancer. However, measuring long-term indoor radon concentration can be difficult, and a statistical model for predicting mean annual indoor radon concentrations may be readily applicable. We investigated the predictability of mean annual radon concentrations using national data on indoor radon concentrations throughout the spring, summer, fall, and winter seasons in Korea. Indoor radon concentrations in Korea were highest in the winter and lowest in the summer. We derived seasonal correction and seasonal adjustment factors for each season based on the method proposed by previous study. However, these factors may not be readily applicable unless measured in a specific season. In this paper, we separate seasonal correction factors for each month of the year (new correction factors) based on correlations between indoor radon and meteorological factors according to housing type. To evaluate the correction factors, we assessed differences between estimated and measured mean annual radon concentrations. Roughly 97% of the estimated values were within ±40 Bq/m3 of actual measured values in detached houses, and roughly 85–87% of the estimated values were within ±40 Bq/m3 of the measured values in other residences. In most cases, the seasonal correction factors and the new correction factors had slightly better agreement than the seasonal adjustment factor. For predicting mean annual radon concentrations, the seasonal correction factors or seasonal adjustment factors can be of use when actual measurements of indoor radon concentrations for a specific season are available. Otherwise, the new correction factors may be more readily applicable.

Indoor Radon Levels and Annual Effective Dose in Dwellings of Najran City, Saudi Arabia

The main objective of this study is to assess the health hazard due to the indoor radon. CR-39 as time-integrated passive solid-state nuclear track detectors (SSNTDs) were used in the indoor radon measurements of Najran City, Saudi Arabia. CR-39 detectors were distributed in dwellings of different places of the city. The detectors were exposed in the dwellings for two months and then etched in NaOH 6.25 N solution at 70 ±1°C for 5 h. This study revealed that the radon concentration in the dwellings ranged from 15.03±1.9 to 70.48±3.3 Bq m-3 with an average of 34.00±14.0 Bq m-3. Comparison of indoor radon concentration measurements in the different floors showed that the radon concentration in ground floors was slightly higher than that in first floors. Results showed that there is no significant health risk from indoor radon concentration and annual effective dose in the study region.

Indoor radon in Spanish workplaces. A pilot study before the introduction of the European Directive 2013/59/Euratom

ObjectiveTo explore whether there is a possible problem regarding indoor radon concentration surpassing the new European Directive 2013/59/Euratom threshold in Spanish workplaces. We also aim to find out whether radon concentration might be associated with certain characteristics of workplaces. MethodWe performed a cross-sectional study to measure indoor radon concentrations in Spanish workplaces including five different sectors (education, public administration, the health sector, the tourist sector and the private sector). To be measured, the workplace should be occupied permanently by at least one worker. Alpha-track type radon detectors were placed for at least three months and read at the Galician Radon Laboratory at the University of Santiago de Compostela. A descriptive analysis was performed on radon distribution by sector, building characteristics and number of workers affected. ResultsWe faced enormous difficulties in finding volunteers for this study. Galicia and Madrid had the highest number of measurements. Of a total of 248 measurements, 27% had concentrations above 300 Bq/m3. Median radon concentration was 251 Bq/m3 in Galicia, followed by Madrid, with 61.5 Bq/m3. Forty-six percent of the workplaces measured in Galicia had radon concentrations higher than 300 Bq/m3 followed by 10.6% in Madrid. Nineteen percent of all workers were exposed to more than 300 Bq/m3 and 6.3% were exposed to radon concentrations higher than 500 Bq/m3. ConclusionIndoor radon exposure might be a relevant problem in Spanish workplaces and the number of affected workers could be high. The prevalence of workers exposed to high radon concentrations probably depends on the geographical area.

Measurement of indoor radon concentration in district Mardan, Khyber Pakhtunkhwa, Pakistan

Measurement of indoor radon concentration in district Mardan, Khyber Pakhtunkhwa, Pakistan