THE RESULTS OF MEASURING AND MODELLING SOIL-INDOORS RADON TRANSPORTATION / RADONO PERNAŠOS IŠ DIRVOŽEMIO Į PATALPAS MATAVIMO IR MODELIAVIMO REZULTATAI

The article presents the entry of radon gas into premises and introduces the parameters accelerating and slowing this process. The paper determines the dependence of radon gas entering the premises on ambient temperature and humidity changes. It is noted that a growth in differences under ambient and indoor temperature increases indoor radon concentrations in the air due to an increase in the intensity of radon exhalation from soil. Also, an increase in the moisture content indoors decreases the volumetric activity of radon in the air. The simulated values of radon volumetric activity in ambient air were similar to those measured using radon monitoring device RTM2200. Radon concentration in the air of the first floor was higher than that in the second floor. Indoor radon concentrations were highest in the winter and lowest in summer season. Article in Lithuanian. Santrauka Nagrinėjama radono dujų patekimo į patalpas procesas, šį procesą spartinantys ir lėtinantys parametrai. Nustatoma radono dujų patekimo į patalpas priklausomybė nuo aplinkos temperatūros bei drėgnio kitimo. Pastebėta, kad, didėjant aplinkos ir patalpos temperatūrų skirtumui, didėja ir radono tūrinis aktyvumas patalpos ore (vasarą radono tūrinis aktyvumas siekė 45,0±3,0 Bq/m3, kai temperatūrų skirtumas buvo 3,1 °C, o rudenį – 62,0±5,0 Bq/m3, esant temperatūrų skirtumui 3,9 °C), didėja radono ekshaliacijos iš dirvožemio intensyvumas, o didėjant drėgmės kiekiui patalpose radono tūrinis aktyvumas ore mažėja. Sumodeliuotos radono tūrinio aktyvumo patalpos ore reikšmės buvo panašios kaip ir išmatuotos naudojant radono monitorių RTM2200. Pirmajame aukšte radono tūrinis aktyvumas ore buvo didesnis nei antrajame. Žiemos sezonu jo vertė buvo didžiausia (47,0±10,5 Bq/m3), o vasaros sezonu – mažiausia (15±1,8 Bq/m3).

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EXPOSURE LEVELS OF UKRAINIAN POPULATION IN THE CONTEXT OF AN ACTION PLAN TO REDUCE INDOOR RADON LEVELS

Проблеми радіаційної медицини та радіобіології = Problems of Radiation Medicine and Radiobiology ◽

10.33145/2304-8336-2020-25-220-229 ◽

2020 ◽

Vol 25 ◽

pp. 220-229

Author(s):

T. Pavlenko ◽

◽

A. Serdiuk ◽

A. Operchuk ◽

M. Aksenov ◽

...

Keyword(s):

Indoor Radon ◽

Action Plan ◽

Geometric Mean ◽

Radiation Risk ◽

Reference Level ◽

Annual Number ◽

Indoor Radon Concentration ◽

Radon Gas ◽

Radiation Risks ◽

Radon Concentrations

Objective. To analyze and evaluate the available information to indoor radon concentration in the context of the implementation of the radon action plan. Methods. Object of study: indoor radon-222 in dwellings by area and corresponding radiation risks of the population. Measurements were performed using passive track radonometry. The exposure time of the radonometers is at least 30 days during heating season. Radiation risk calculations were performed according to the dose coefficients and mathematical models of the ICRP. Results. It was found that for the whole country, reference level 300 Bq/m3 (radon gas) is exceeded in 16 % of cases. It was found that geometric mean of radon gas levels was 120 Bq/m3 and varies from 35 to 265 Bq/m3 by different area, namely the difference between radon levels in different territories of the country can be up to 7.5 times. Variability of radon levels at the district level is also significant. It was found, radon activity concentration differing by almost 10 times by districts with lognormal distribution and a geometric mean of 75 Bq/m3. The analysis of radiation risks of the population has established that estimated annual number of lung cancer deaths due to radon in Ukraine is almost 8,900 cases; and а direct economic loss for the country are estimated at more than $ 450 million a year. Conclusions. Surveys of radon levels demonstrated significant variation in radon concentrations between different regions. For the whole country, reference level (300 Bq/m3) is exceeded on above 16 % of the dwellings, but percentage of exceeding varies from 0.1 to 43.0 % by different area. Information on indoor radon concentrations in almost a third of the country is non-available. For an effective implementation of the Action plan, it makes sense to introduce radon risk mapping. Key words: indoor radon, reference level, population, radiation risk, economic cost.

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Measurement of radon concentrations for some houses in Al-Najaf city /Iraq

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v11i22.352 ◽

2019 ◽

Vol 11 (22) ◽

pp. 51-55 ◽

Cited By ~ 1

Author(s):

Ali A. Al-Hamidawi

Keyword(s):

Solid State ◽

Radon Concentration ◽

Concentration Level ◽

Indoor Radon ◽

Summer Season ◽

Alpha Particles ◽

Indoor Radon Concentration ◽

Long Term Measurement ◽

Radon Concentrations

Measurement of radon concentration level was carried out in 40 houses in Al – Najaf city during summer season of 2012. Long term measurement of indoor of old building radon concentrations have been taken, using a previously calibrated passive diffusion dosimeters containing CR – 39 solid state nuclear track detectors which are very sensitive for alpha particles. The measurement of the indoor radon concentration obtained in summer in these regions ranged from 11.654±4.216 Bq.m-3 to 53.610±8.777 Bq.m-3. The results were within universally permitted levels.

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Measurement of indoor radon concentrations in Kuwait

Environment International ◽

10.1016/0160-4120(87)90187-5 ◽

1987 ◽

Vol 13 (4-5) ◽

pp. 323-330 ◽

Cited By ~ 2

Author(s):

Adel A. Mustafa ◽

C.M. Vasisht ◽

J. Sabol

Keyword(s):

Indoor Radon ◽

Radon Concentrations

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Radiological Assessment of Indoor Radon and Thoron Concentrations and Indoor Radon Map of Dwellings in Mashhad, Iran

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18010141 ◽

2020 ◽

Vol 18 (1) ◽

pp. 141

Author(s):

Mohammademad Adelikhah ◽

Amin Shahrokhi ◽

Morteza Imani ◽

Stanislaw Chalupnik ◽

Tibor Kovács

Keyword(s):

Limit Of Detection ◽

Indoor Radon ◽

Absolute Error ◽

Soil Gas ◽

Indoor Radon Concentration ◽

Soil Gas Radon ◽

Distance Weighting ◽

The City ◽

Monitoring Devices ◽

Radon Concentrations

A comprehensive study was carried out to measure indoor radon/thoron concentrations in 78 dwellings and soil-gas radon in the city of Mashhad, Iran during two seasons, using two common radon monitoring devices (NRPB and RADUET). In the winter, indoor radon concentrations measured between 75 ± 11 to 376 ± 24 Bq·m−3 (mean: 150 ± 19 Bq m−3), whereas indoor thoron concentrations ranged from below the Lower Limit of Detection (LLD) to 166 ± 10 Bq·m−3 (mean: 66 ± 8 Bq m−3), while radon and thoron concentrations in summer fell between 50 ± 11 and 305 ± 24 Bq·m−3 (mean 115 ± 18 Bq m−3) and from below the LLD to 122 ± 10 Bq m−3 (mean 48 ± 6 Bq·m−3), respectively. The annual average effective dose was estimated to be 3.7 ± 0.5 mSv yr−1. The soil-gas radon concentrations fell within the range from 1.07 ± 0.28 to 8.02 ± 0.65 kBq·m−3 (mean 3.07 ± 1.09 kBq·m−3). Finally, indoor radon maps were generated by ArcGIS software over a grid of 1 × 1 km2 using three different interpolation techniques. In grid cells where no data was observed, the arithmetic mean was used to predict a mean indoor radon concentration. Accordingly, inverse distance weighting (IDW) was proven to be more suitable for predicting mean indoor radon concentrations due to the lower mean absolute error (MAE) and root mean square error (RMSE). Meanwhile, the radiation health risk due to the residential exposure to radon and indoor gamma radiation exposure was also assessed.

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Environmental Effects on the Static and Fatigue Behaviours of Hemp Fibre under Tensile Loading

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.798.410 ◽

2015 ◽

Vol 798 ◽

pp. 410-418

Author(s):

Anh Dung Ngo ◽

Thu Nga Ho ◽

Khalid Sefrioui Manar

Keyword(s):

Mechanical Properties ◽

Moisture Content ◽

Failure Modes ◽

Harmful Effect ◽

Tensile Loading ◽

Ambient Air ◽

Absorption Mechanism ◽

Hemp Fibre ◽

Temperature And Humidity ◽

Static Tensile

Environmental and loading mode effects on the tensile properties of Hemp fibre were investigated. At first, absorption of moisture into the fibre from ambient air and absorption of water into the fibre in immersion were studied. Then static and cyclic loadings tensile tests were conducted in various temperature and humidity conditions. It was found that, in ambient air (0% < RH < 80%) the moisture content of the studied fibre decreased with the increase of temperature conformed to the GAB model suggesting a multilayer absorption mechanism. On the contrary, for the fibre immersed in water, the moisture content increased with the increase of temperature. The activation of temperature on the diffusion of the water into the fibre by micro-pores and lumens jointly with the lack of possibility for the imprisoned water to evaporate might be the cause of this effect. Experimental results suggested that temperature and humidity could individually reduce the mechanical properties of Hemp fibre. Their interaction caused even a more harmful effect. Semi empirical and neural networks were used to predict the hygro-thermal effects on the mechanical properties under static tensile loading. Broken surfaces of the specimens were also examined showing different failure modes for static and cyclic tensile loadings. Finally, the value of the cellulose micro-fibrils angle (MFA) estimated using the static tensile stress-strain curve was 8.4o±1.9o.

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