scholarly journals Radon and thoron exhalation rate measurements from building materials used in Serbia

Nukleonika ◽  
2020 ◽  
Vol 65 (2) ◽  
pp. 111-114
Author(s):  
Igor T. Čeliković ◽  
Gordana K. Pantelić ◽  
Miloš Z. Živanović ◽  
Ivana S. Vukanac ◽  
Jelena D. Krneta Nikolić ◽  
...  

AbstractThe second most important source of indoor radon, after soil beneath dwelling, is building material. With the increase in environmental awareness and new energy-saving policies, residents tend to replace the existing windows with tighter windows, which leads to a decrease in air exchange rate and consequently an increase in indoor radon concentration. In case of low exchange rates, dose caused by inhalation of radon and its progeny can exceed external dose originating from the radium content in the surrounding building material. In this paper, surface exhalation rates of radon (222Rn) and thoron (220Rn) from typical building materials used for construction and interior decoration of houses in Serbia were investigated. Surface exhalation rate measurements were performed using the closed-chamber method, while concentrations of radon and thoron in the chamber were continuously measured using an active device, RTM1688-2, produced by SARAD® GmbH. Finally, the impact of the replacement of windows on the indoor radon concentration was estimated.

2019 ◽  
Vol 188 (1) ◽  
pp. 30-37
Author(s):  
Irene Opoku-Ntim ◽  
Aba Bentil Andam ◽  
Vicenzo Roca ◽  
J J Fletcher ◽  
T T Akiti

Abstract 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 6 months each. Average indoor radon concentration varied from 63.9 to 364.9 Bqm−3 with a mean of 152.2 ± 10.9 Bqm−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 ± 0.3 mSvy−1 for the rainy season and for the dry season, effective dose of 0.6 mSvy−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.


2020 ◽  
pp. 1420326X2096338
Author(s):  
Chenhua Wang ◽  
Dong Xie ◽  
Chuck Wah Yu ◽  
Hanqing Wang

Radium, which is naturally present in many building materials, decays to the radioactive gas radon, which is exhaled from the surface of concrete block and is a major source of human exposure to radioactivity. In this study, an experimental evaluation of radon exhalation was conducted on a concrete block covered with mortar and acrylic render. Factors such as sand aggregates content and water content of the mortar cover layer, the thickness of the double cover layer were considered. Results showed that the radon exhalation rate was increased with an increase of sand content in mortar cover layer, and the radon exhalation rate was reduced with an increase of the thickness and water content. Besides, indoor radon concentration and effective dose estimation involving concrete block with cover layer were evaluated. The calculated indoor radon concentration was reduced from 234.9 to 201.1 Bq m−3 as the thickness of the cover layer was increased from 15 to 35 mm, and the effective dose was reduced by 0.61 mSv y−1. Therefore, the addition of a cover layer on the indoor walls, floors and ceilings could reduce the indoor radon concentration and the radon dose on exposure to occupants.


Nukleonika ◽  
2020 ◽  
Vol 65 (2) ◽  
pp. 71-76
Author(s):  
Carlo Lucchetti ◽  
Mauro Castelluccio ◽  
Matteo Altamore ◽  
Alessandra Briganti ◽  
Gianfranco Galli ◽  
...  

AbstractIn the frame of Radon rEal time monitoring System and Proactive Indoor Remediation (RESPIRE), a LIFE 2016 project funded by the European Commission, the contribution of building materials of volcanic origin to indoor radon concentration was investigated. First, total gamma radiation and related outdoor dose rates of geological materials in the Caprarola area (Central Italy) were measured to define main sources of radiation. Second, 222Rn and 220Rn exhalation rates of these rocks used as building materials were measured using an accumulation chamber connected in a closed loop with a RAD7 radon monitor. Among others, the very porous “Tufo di Gallese” ignimbrite provided the highest values. This material was then used to construct a scale model room of 62 cm × 50 cm × 35 cm (inner length × width × height, respectively) to assess experimental radon and thoron activity concentration at equilibrium and study the effects of climatic conditions and different coatings on radon levels. A first test was carried out at ambient temperature to determine experimental 222Rn and 220Rn equilibrium activities in the model room, not covered with plaster or other coating materials. Experimental 222Rn equilibrium was recorded in just two days demonstrating that the room “breaths”, exchanging air with the outdoor environment. This determines a dilution of indoor radon concentration. Other experiments showed that inner covers (such as plasterboard and different kinds of paints) partially influence 222Rn but entirely cut the short-lived 220Rn. Finally, decreases in ambient temperature reduce radon exhalation from building material and, in turn, indoor activity concentration.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Dicu ◽  
B. D. Burghele ◽  
M. Botoş ◽  
A. Cucoș ◽  
G. Dobrei ◽  
...  

AbstractThe present study aims to identify novel means of increasing the accuracy of the estimated annual indoor radon concentration based on the application of temporal correction factors to short-term radon measurements. The necessity of accurate and more reliable temporal correction factors is in high demand, in the present age of speed. In this sense, radon measurements were continuously carried out, using a newly developed smart device accompanied by CR-39 detectors, for one full year, in 71 residential buildings located in 5 Romanian cities. The coefficient of variation for the temporal correction factors calculated for combinations between the start month and the duration of the measurement presented a low value (less than 10%) for measurements longer than 7 months, while a variability close to 20% can be reached by measurements of up to 4 months. Results obtained by generalized estimating equations indicate that average temporal correction factors are positively associated with CO2 ratio, as well as the interaction between this parameter and the month in which the measurement took place. The impact of the indoor-outdoor temperature differences was statistically insignificant. The obtained results could represent a reference point in the elaboration of new strategies for calculating the temporal correction factors and, consequently, the reduction of the uncertainties related to the estimation of the annual indoor radon concentration.


2020 ◽  
Vol 191 (2) ◽  
pp. 219-222
Author(s):  
Tatiana Petrova ◽  
Petr Miklyaev

Abstract Continuous indoor radon measurements were carried out in two traditional Russian rural houses located in different villages of the Moscow region in summer of 2017 and 2018. In additional, in the summer of 2017, continuous measurements of soil gas radon activity concentration at depth 0.8 m and radon exhalation rate from the ground surface near the house were performed simultaneously. It was found that the indoor radon concentration in rural houses is subject to strong daily variations, which are characterized by highs at night and lows during the day. Indoor radon concentration is directly proportional to indoor and outdoor temperature difference and inversely proportional to wind speed. While the radon exhalation rate from the ground surface, as well as the ventilation of premises (opening doors and windows) practically do not affect the concentration of radon in Russian rural wooden houses.


Author(s):  
Sheldwin A. Yazzie ◽  
Scott Davis ◽  
Noah Seixas ◽  
Michael G. Yost

Uranium is naturally found in the environment as a radioactive metal element with high concentrations in the Southwestern US. In this region is the Navajo Nation, which spans approximately 69,930 square kilometers. A decay product of uranium is radon gas, a lung carcinogen that has no color, odor, or taste. Radon gas may pass from soil into homes; and, indoor accumulation has been associated with geographical location, seasonality, home construction materials, and home ventilation. A home and indoor radon survey was conducted from November 2014 through May 2015, with volunteers who reported residence on the Navajo Nation. Home geolocation, structural characteristics, temperature (°C) during radon testing, and elevation (meters) were recorded. Short-term indoor radon kits were used to measure indoor radon levels. 51 homes were measured for indoor radon levels, with an arithmetic mean concentration of 60.5 Becquerels per cubic meter (Bq/m3) (SD = 42.7). The mean indoor radon concentrations (Bq/m3) by house type were: mobile, 29.0 (SD = 22.9); wood, 58.6 (SD = 36.0); hogan, 74.0 (SD = 0.0); homes constructed of cement and wood, 82.6 (SD = 3.5); and homes constructed of concrete and cement, 105.7 (SD = 55.8). A key observation is that house construction type appears to be associated with the mean home indoor radon concentration. This observation has been published in that the basic structural make-up of the home may affect home ventilation and therefore indoor radon concentration levels.


2017 ◽  
Vol 27 (7) ◽  
pp. 1001-1014 ◽  
Author(s):  
Sudhir Mittal ◽  
Asha Rani ◽  
Rohit Mehra ◽  
B. K. Sahoo ◽  
B. K. Sapra

The annual variation in radon and thoron concentrations in different seasons has been revealed for 40 different locations of Jodhpur, Nagaur, Bikaner and Jhunjhunu districts of Northern Rajasthan by using pinhole dosimeter, and the results have been compared with ventilation conditions and building materials. The indoor radon concentration was observed to vary from 109 ± 17 to 334 ± 13 Bq m−3, 63 ± 17 to 255 ± 21 Bq m−3, 45 ± 11 to 128 ± 19 Bq m−3 and 74 ± 9 to 300 ± 21 Bq m−3 and thoron concentration varies from 26 ± 15 to 418 ± 21 Bq m−3, 3 ± 2 to 134 ± 33 Bq m−3, 12 ± 6 to 140 ± 19 Bq m−3 and 6 ± 4 to 408 ± 29 Bq m−3 for winter, spring, summer and autumn seasons, respectively. In winter season, indoor radon concentration of about 50% dwellings was observed to be within or higher than the action level as recommended by International Commission of Radiation Protection. However, in summer the action level is lower than the action limit. The exposure of human beings to indoor radon and thoron and the associated risk has also been examined. The total annual mean effective dose due to indoor radon and thoron in Northern Rajasthan are less than or close to the action level 3–10 mSv y−1 as recommended by International Commission of Radiation Protection.


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