An approach to predicting indoor radon concentration based on depressurisation measurements

Entry Rate ◽

Energy Retrofit ◽

Building Characteristics ◽

Passive Measurements ◽

Exposure to radon is recognised as the second-leading cause of lung cancer after tobacco smoke. The passive measurements typically take up to three months to be representative of the annual radon concentration. A recently developed approach depressurises a dwelling to heighten the convective radon flux determining radon entry rate coefficients. The current study characterises the ventilation status, air tightness and eight selected hourly air change rates measurements, of a sample of naturally ventilated dwellings in Ireland. The household averaged air change rate ranged from 0.28 to 1.87 h−1 and airtightness measurements ranged from 4.830 to 9.423 m3 h−1 m−2 @ 50 Pa, depending on the building characteristics. The experimentally obtained values were used to parameterise a computational model for these selected dwellings and to predict radon concentrations. The radon entry rate power laws ranged from 0.18ΔP0.97 to 1.28ΔP1.18 Bq s−1. Probabilistic functions were generated based on the experimental data and predicted radon concentrations were within one standard deviation of the experimentally measured values in three out of four cases. The data generated can be used in modelling simulations to predict indoor radon concentrations based on local meteorological conditions, building characteristics, ventilation guidelines and energy-retrofit measurements.

Long-Term Impacts of Weather Conditions on Indoor Radon Concentration Measurements in Switzerland

Atmosphere ◽

10.3390/atmos13010092 ◽

2022 ◽

Vol 13 (1) ◽

pp. 92

Author(s):

Joan Frédéric Rey ◽

Stéphane Goyette ◽

Mauro Gandolla ◽

Martha Palacios ◽

Fabio Barazza ◽

...

Keyword(s):

Radon Concentration ◽

Indoor Radon ◽

Weather Conditions ◽

Indoor Environments ◽

Prone Area ◽

Building Characteristics ◽

Study Sites ◽

Radon Measurements

Radon is a natural and radioactive gas that can accumulate in indoor environments. Indoor radon concentration (IRC) is influenced, among other factors, by meteorology, which is the subject of this paper. Weather parameters impact indoor radon levels and have already been investigated, but rarely in Switzerland. Moreover, there is a strong need for a better understanding of the radon behaviour inside buildings in Switzerland for public health concerns as Switzerland is a radon prone area. Based on long-term, continuous, and hourly radon measurements, radon distributions classified according to different weather event definitions were investigated and then compared at three different study sites in Western Switzerland. Outdoor temperature influences the most indoor radon, and it is globally anti-correlated. Wind influences indoor radon, but it strongly depends on intensity, direction, and building characteristics. Precipitation influences periodically indoor radon levels relatively to their intensity. Atmospheric pressure and relative humidity do not seem to be huge determinants on IRC. Our results are in line with previous findings and provide a vivid example in Western Switzerland. This paper underlines the different influence complexities of radon, and the need to communicate about it within the broader public and with construction professionals, to raise awareness.

Radon measurements with CR-39 track detectors at specific locations in Turkey

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp0401046u ◽

2004 ◽

Vol 19 (1) ◽

pp. 46-49 ◽

Cited By ~ 6

Author(s):

Asiye Ulug ◽

Melek Karabulut ◽

Nilgün Celebi

Keyword(s):

Radon Concentration ◽

Indoor Radon ◽

Active Faults ◽

Arithmetic Means ◽

Radon Measurements ◽

New Buildings ◽

Main Factor ◽

Ventilation Conditions ◽

Indoor radon concentration levels at three sites in Turkey were measured using CR-39 solid state nuclear track detectors. The annual mean of radon concentration was estimated on the basis of four quarter measurements at specific locations in Turkey. The measuring sites are on the active faults. The results of radon measurements are based on 280 measurements in doors. The annual arithmetic means of radon concentrations at three sites (Isparta Egirdir, and Yalvac) were found to be 164 Bqm?3, 124 Bqm?3, and 112 Bqm?3 respectively, ranging from 78 Bqm?3 to 279 Bqm?3. The in door radon concentrations were investigated with respect to the ventilation conditions and the age of buildings. The ventilation conditions were determined to be the main factor affecting the in door radon concentrations. The in door radon concentrations in the new buildings were higher than ones found in the old buildings.

The Alpha Particle Doses Received by Students and Staff in Twenty Schools in the North of Hebron Region - Palestine

Jordan Journal of Physics ◽

10.47011/14.4.4 ◽

2021 ◽

Vol 14 (4) ◽

pp. 309-316

Keyword(s):

Effective Dose ◽

Radon Concentration ◽

Annual Effective Dose ◽

Indoor Radon ◽

Alpha Particles ◽

The North ◽

Cr 39 Detectors ◽

Average Effective Dose ◽

Abstract: The aim of the current study was to measure indoor radon concentration levels and its resulting doses received by the students and staff in schools of the directorate of education in the north of Hebron region- Palestine, during the summer months from June to September (2018), using CR-39 detectors. In this study, a total of 567 CR-39-based radon detectors were installed in the selected schools. The average radon concentrations were found to be 90.0, 66.5 and 58.0 Bqm-3 in Halhul, Beit Umar and Alarrub camp schools, respectively. Based on the measured indoor radon data, the overall average effective dose for the studied area was found to be 0.31 mSvy-1. Reported values for radon concentrations and corresponding doses are lower than ICRP recommended limits for workplaces. The results show no significant radiological risk for the pupils and staff in the schools under investigation. Consequently, the health hazards related to radiation are expected to be negligible. Keywords: Radon concentration, Alpha particles, Annual effective dose, Schools. PACs: 29.40.−n.

A reconnaissance study of radon concentrations in Hamadan city, Iran

Natural Hazards and Earth System Science ◽

10.5194/nhess-10-857-2010 ◽

2010 ◽

Vol 10 (4) ◽

pp. 857-863 ◽

Cited By ~ 14

Author(s):

G. K. Gillmore ◽

N. Jabarivasal

Keyword(s):

Radon Concentration ◽

Limit Of Detection ◽

Indoor Radon ◽

Alluvial Fan ◽

Winter Period ◽

Radiological Protection ◽

Western Iran ◽

Surficial Deposits ◽

Abstract. This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 (i.e. below the lower limit of detection for the method) to 364 Bq/m3 with a mean value of 108 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration – these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March) with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP) in 1993. This study supports other work in a number of countries that indicates such permeable "surficial" deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings.

Short-Term Measurement of Indoor Radon Concentration in Northern Croatia

Applied Sciences ◽

10.3390/app10072341 ◽

2020 ◽

Vol 10 (7) ◽

pp. 2341 ◽

Cited By ~ 1

Author(s):

Anita Ptiček Siročić ◽

Davor Stanko ◽

Nikola Sakač ◽

Dragana Dogančić ◽

Tomislav Trojko

Keyword(s):

Radon Concentration ◽

Indoor Radon ◽

Geometric Mean ◽

Construction Materials ◽

Health Issues ◽

Short Term ◽

Ground Floor ◽

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.

Construction a process to measurement the indoor radon concentration

Science and Technology Development Journal ◽

10.32508/stdj.v16i3.1619 ◽

2013 ◽

Vol 16 (3) ◽

pp. 53-60

Author(s):

Hien Thi To ◽

Nguyen Thao Nguyen ◽

Huy Huu Duong

Keyword(s):

Lung Cancer ◽

Exposure Time ◽

Radon Concentration ◽

Indoor Radon ◽

Construction Process ◽

Radon Exposure ◽

Indoor Location ◽

Radon Inhalation ◽

Radon is a naturally radioactive gas , but it causes lung cancer to humans. The risk of lung cancer due to radiation depends on the amount of radon inhalation and radon exposure time. In Vietnam, radon concentrations are usually determined by RAD7, however RAD7 just showed the immediate values of radon, and have to regularly calibrate it. The construction process to determine the accumulates indoor radon concentration by detector CR- 39 in order to be widely used in the study of environmental pollution, especially the study of health risks of radon for humans and mapping radon pollution. Detector CR - 39 is placed in a 7 cm - plastic holder, and in exposure time, the holders were covered with glass fiber filter paper ∅ 47mm on the bottom of the detector to avoid the exposure of dust. Then it is hung in the indoor location as Vietnam Standard 7889:2008. After 3 months, holders are returned to a laboratory, and CR - 39 will be soaked in 6M NaOH at 700C. Indoor radon concentrations will be proportional to the density traces obtained on CR-39. The study uses an radium 226 source of the NIST (National Institute for Standards and Technology) with the released radon coefficient : f = 0.891 ± 0.015. Results show the calibration factor K is 4.533 ± 0.218 [(Bq.m-3. day)]/(tracks / CR-39)]. Using K factor, we can determine the cumulative indoor radon concentration.

A study of diurnal and short-term variations of indoor radon concentrations at the University of Michigan, USA and their correlations with environmental factors

Indoor and Built Environment ◽

10.1177/1420326x16660755 ◽

2016 ◽

Vol 26 (8) ◽

pp. 1051-1061 ◽

Cited By ~ 14

Author(s):

Dong Xie ◽

Maili Liao ◽

Hanqing Wang ◽

Kimberlee J. Kearfott

Keyword(s):

Radon Concentration ◽

Indoor Radon ◽

Environmental Parameters ◽

Barometric Pressure ◽

University Of Michigan ◽

Outdoor Temperature ◽

Hourly Rainfall ◽

The University ◽

Measurements of indoor radon concentrations and environmental parameters were collected continuously on an hourly basis over a three-month period (April 2012 to June 2012). These were performed both in a well-ventilated ground floor laboratory and in the unventilated basement directly below it in a two-storey building at the University of Michigan, USA. The diurnal variations of indoor radon concentration were investigated along with their correlations to the environmental parameters. The results showed that in the laboratory with typical air exchange, the highest radon values appeared in the early morning while lower values emerged in the afternoon. A similar time-course was followed by radon concentrations in the basement with stagnant air. The day-average radon concentrations in the laboratory ranged from 27 ± 2 Bq m−3 to 54 ± 5 Bq m−3, with the overall mean of 37 ± 6 Bq m−3 over the three-month data collection period. The overall basement average, 900 ± 92 Bq m−3 is significantly higher than the population-weighted world average value of 39 Bq m−3. For the ground-level laboratory, the indoor humidity, outdoor temperature and indoor–outdoor temperature difference were positively correlated with indoor radon. The indoor radon negatively correlated with outdoor barometric pressure, wind speed and indoor–outdoor barometric pressure differences. However, for the unventilated basement, the only statistically significant correlation of indoor radon concentration was a positive one with hourly rainfall.

Radon concentrations in multi-story buildings in Montenegro

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp181108020v ◽

2019 ◽

Vol 34 (2) ◽

pp. 165-174

Author(s):

Perko Vukotic ◽

Ranko Zekic ◽

Nevenka Antovic ◽

Tomislav Andjelic

Keyword(s):

Radon Concentration ◽

Building Materials ◽

Indoor Radon ◽

Small Contribution ◽

Climate Conditions ◽

Floor Level ◽

Radon Activity ◽

Activity Concentrations ◽

Change of radon concentrations in dwellings with floor level was studied in six multi-story buildings, in four towns of Montenegro with different climate conditions. The annual aver- age radon activity concentrations in 35 dwellings are found to be very low, mostly at a level of 20-30 Bqm?3. Absorbed gamma dose rates in these dwellings are in the range of 14-58 nGyh?1. The low radon concentrations are a consequence of a good tightness of the structures in contact with the ground and a small contribution of building materials to radon indoors. A clear general trend of changes in radon concentrations with floor level is not observed. In most of the dwellings on different floors in the multi-story building radon concentration varies very little, mostly within measurement error. A small decrease in radon concentration is noted between the two or three floors closest to the ground, but only in some of the buildings. Therefore, a decrease of indoor radon concentration with floor level cannot be considered as a general characteristic of multi-story buildings. Although the seasonal radon variations have not been in the focus of this study, it was found that the average radon activity concentrations in dwellings of the multi-story buildings are higher in warmer than in cooler half-year period, what is contrary to the general rule for homes in the world and in Montenegro as well.

Comparison of Predicted and Measured Variations of Indoor Radon Concentration

Radiation Protection Dosimetry ◽

10.1093/oxfordjournals.rpd.a080276 ◽

1988 ◽

Vol 24 (1-4) ◽

pp. 231-235 ◽

Cited By ~ 20

Author(s):

H. Arvela ◽

A. Voutilainen ◽

I. Mäkeläinen ◽

O. Castrén ◽

K. Winqvist

Keyword(s):

Seasonal Variations ◽

Radon Concentration ◽

Pressure Difference ◽

Indoor Radon ◽

Entry Rate ◽

Concrete Walls ◽

Factors Affecting ◽

Air Infiltration ◽

Concentration Ratios

Abstract Prediction of the variations of indoor radon concentration were calculated using a model relating indoor radon concentration to radon entry rate, air infiltration and meteorological factors. These calculated variations have been compared with seasonal variations of 33 houses during 1-4 years, with winter-summer concentration ratios of 300 houses and the measured dirunal variation. In houses with a slab in ground contact the measured seasonal variations are quite often in agreement with variations predicted for nearly pure pressure difference driven flow. The contribution of a diffusion source is significant in houses with large porous concrete walls against the ground. Air flow due to seasonally variable thermal convection within eskers strongly affects the seasonal variations within houses located thereon. Measured and predicted winter-summer concentration ratios demonstrate that, on average, the ratio is a function of radon concentration. The ratio increases with increasing winter concentration. According to the model the diurnal maximum caused by a pressure difference driven flow occurs in the morning, a finding which is in agreement with the measurements. The model presented can be used for differentiating between factors affecting radon entry into houses.

Estimation of Seasonal Correction Factors for Indoor Radon Concentrations in Korea

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15102251 ◽

2018 ◽

Vol 15 (10) ◽

pp. 2251 ◽

Cited By ~ 7

Author(s):

Ji Park ◽

Cheol Lee ◽

Hyun Lee ◽

Dae Kang

Keyword(s):

Lung Cancer ◽

Radon Concentration ◽

Indoor Radon ◽

Seasonal Adjustment ◽

Correction Factors ◽

Housing Type ◽

Adjustment Factors ◽

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.