scholarly journals Radon exhalation rates from common building materials in India: Effect of back diffusion

2016 ◽  
Vol 31 (3) ◽  
pp. 277-281
Author(s):  
Amit Kumar ◽  
Pal Chauhan

A radon exhalation study for building materials was carried out by closed accumulator technique using plastic track detector LR-115 type-II, taking into account the effect of back diffusin. The back diffusion of radon into the materials causes an underestimate of free exhalation rates. The results showed that radon exhalation rates of soil, sand, brick powder, and crasher were found to be high as compared to rice husk ash, wall putty, and plaster of Paris. The radon exhalation rates from building materials varied from 0.45 ? 0.07 mBq/kgh to 1.55 ? 0.2 mBq/kgh and 3.4 ? 0.7 mBq/m2h to 28.6 ? 3.8 mBq/m2h as measured without considering back diffusion. The radon exhalation rates of building materials oblivious of back diffusion varied from 4.3 ? 0.8 mBq/m2h to 44.1 ? 5.9 mBq/m2h. The radon exhalation rates from building materials can be used for estimation of radon wall flux and indoor radon concentration. Thus, it is necessary to make correction in the measured exhalation rates by back diffusion.

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.


2016 ◽  
Vol 27 (2) ◽  
pp. 278-288 ◽  
Author(s):  
Emre Tabar ◽  
Hakan Yakut ◽  
Adem Kuş

In the present study, radon exhalation rates in terms of mass and area, as well as the effective radium concentration in soil samples collected simultaneously from different districts of southern Sakarya have been measured by Sealed Can technique using LR-115 type-II detectors. Mass and areal radon exhalation rates in soil samples vary from 35.76 ± 1.5 to 253.15 ± 3.8 mBqkg−1h−1 with an average value of 112.53 ± 2.7 mBqkg−1h−1 and 0.73 ± 0.2 to 5.18 ± 0.6 Bqm−2h−1 with an average value of 2.30 ± 0.6 Bqm−2h−1, respectively. The effective radium content was found to vary in the range 3.77 ± 0.5 to 26.69 ± 1.3 Bqkg−1 with an average value of 11.86 ± 0.9 Bqkg−1. The area exhalation rate was also used to calculate indoor radon concentration contributed by radon exhalation from soil, and to estimate annual effective dose equivalent. While the indoor radon concentration contributed by radon exhalation from soil varies from 2.93 ± 0.9 to 20.73 ± 2.3 Bqm−3 with an average value of 9.22 ± 1.5 Bqm−3, the estimated effective dose equivalent varies from 0.09 to 0.61 mSvy−1 with an average value of 0.27 mSvy−1.


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.


2020 ◽  
Vol 191 (3) ◽  
pp. 296-309
Author(s):  
F Otoo ◽  
I Arhin ◽  
E O Darko

Abstract Studies have been carried in 126 dwellings for indoor radon levels and 43 soil samples for radium and radon exhalation rate of Abirem communities in Eastern region of Ghana. The measurements were done using CR-39 and HPGe techniques. Indoor radon and mean concentration ranged from 23.8 to 125.7 Bq/m3, 54.7 ± 23.7 Bq/m3. Bedroom, kitchen, and sitting varied from 30.8 to 125.7 Bq/m3, 23.8–63.9 Bq/m3 and 23.8 to 58.4 Bq/m3. Strong and weak Pearson correlation were found between radium and radon in soil, radium and indoor radon concentration. Radium concentration and mean were found to be varied from 19.5 to 38.9 Bq/kg, 29.0 ± 16.0 Bq/kg. The radon exhalation rate and mean in soil were also found to be varied from 21.3 to 112.1 μBq/m2h, 65.1 ± 27.6 μBq/m2h. Indoor radon values and radium concentration in dwellings and soil recorded 8% and 38%, respectively, more than action proposed by WHO and UNSCEAR 2000. The estimated annual effective doses and cancer risk were less than the average values recommended by UNSCEAR and ICRP.


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