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1

Using a scale model room to assess the contribution of building material of volcanic origin to indoor radon

Lucchetti Carlo, Castelluccio Mauro, Altamore Matteo, Briganti Alessandra, Galli Gianfranco, Soligo Michele, Tuccimei Paola, Voltaggio Mario

Nukleonika

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2020

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Vol. 65, No. 2

71--76

EN

In 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.

2

Configuration of the parameters for scanner-based track detector evaluation system

Csordás Anita, Tóth-Bodrogi Edit, Kovács Tibor

Nukleonika

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2020

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Vol. 65, No. 2

133--137

EN

According to the new European Union Basic Safety Standards (EU-BSS), preparation of the National Radon Action Plan is obligatory for the Member States. One of the plan’s aims is to carry out an indoor radon survey to identify radon-prone areas. In the radon surveys, track detector methods are used. At the University of Pannonia (Veszprém, Hungary), a new scanner-based detector evaluation system has been developed. For the application of the new system, the selection of appropriate parameters is necessary. In this study, selection of the applied track detectors and setting of the etching conditions have been carried out. Two different types of allyl diglycol carbonate (ADC or CR-39) track detectors were investigated, taking into account the detector’s background and response during the exposure (determination of calibration factor). The Baryotrak’s background track density (0–1.5 tracksmm–2) was lower than that of the 0.8–4 tracksmm–2. The response of the Tastrak was higher, but the deviation of the calibration factor was much higher (1.2–5.3 × 10–3 tracksmm–2/(Bqdaym–3)) than in the case of the Baryotrak (1.4–2.8 × 10–3 tracksmm–2/(Bqdaym–3)). After the systematic review of the etching system, a new method was developed. For the determination of the optimal track diameter, the argon fluoride (ArF) laser was applied to create tracks with diameters in the range of 10–100 µ. The optimum track size was in the range of 40–60 µ. On this basis, new etching conditions were determined: 6.25 M NaOH solution, a temperature of 90 degree centigrade, and time period of 8 hours.

3

Rapid estimation of environmental radioactivity surrounding Xiangshan uranium deposits, Jiangxi province, Eastern China

Gan N., Cen K., Ye R., Li T.

Nukleonika

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2018

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Vol. 63, No. 4

113--121

EN

The surveys of terrestrial gamma dose rate, radon concentration indoor and in water and specific activity of radionuclides of soil were carried out in 14 villages and a town in Xiangshan uranium deposit and surrounding area, Jiangxi province, Eastern China, in 2017–2018, using a scintillator dosemeter, an ionization chamber and a high-purity germanium gamma spectrometer to study radiation status in these places after remediation. A radioactive hot spot was discovered in a village near the mining office, where specific activity of 238U, 226Ra, 232Th and 137Cs of soil was as high as 1433 ± 76 Bq/kg, 1210 ± 62 Bq/kg, 236 ± 13 Bq/kg and 17 ± 1.1 Bq/kg, respectively. The dose rate on a waste rock heap was about 2423 nGy/h. Approximately 50% of the houses in a village near the uranium mining site had radon concentrations that exceeded 160 Bq/m3 . There was a significant positive correlation between indoor radon concentration and outdoor gamma dose rate (R2 = 0.7876). The abnormal radon concentration was observed in a rising spring sample providing residents with tap water up to 127.1 Bq/l. Four tap water samples and three of five well water samples exceeded the limit of radon concentration of drinking water in China (11.1 Bq/l). The mean annual effective doses from gamma dose rate data were 0.86 mSv/y and 1.13 mSv/y for indoor radon. The study shows that there are some radioactively contaminated places surrounding the Xiangshan uranium mine. The local outdoor dose rate averages may be used to estimate local indoor radon concentrations.

4

A study of indoor radon, thoron and their exhalation rates in the environment of Fazilka district, Punjab, India

Narang S., Kumar D., Sharma D. K., Kumar A.

Acta Geophysica

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2018

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Vol. 66, no. 5

1233--1241

EN

Over the last few decades, the study of radioactive radon gas has gained huge momentum due to its possible role in health related hazards. In the present work, pin-hole twin chamber single entrance dosimeters have been used for track measurements of radon and thoron. The annual average radon concentration varies from 50.3 to 204 Bq/m3 at all locations. Almost all the values are below the safe range provided by ICRP. Radon concentration is found to be higher in winter as compared to other seasons. Variation of radon with quality of dwellings is also discussed. The values of annual effective dose due to radon and thoron are also well within the range provided by ICRP and WHO. Radon and thoron exhalation rates are measured using SMART RnDuo monitor. The radon mass exhalation rates ranged from 11 to 71 mBq/kg/h while the thoron surface values ranged from 36 to 2048 Bq/m2/h. All the values are on the lower side. A weak correlation is found between radon and thoron concentrations and their exhalation rates. When compared with the values of other parts of northern India, the values of present investigation are on higher side.

5

Results of the 2015 national indoor radon intercomparison measurements in Serbia

Forkapić S., Bikit K., Arsić V., Ilić J., Pantelić G., Živanović M.

Nukleonika

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2016

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Vol. 61, No. 3

321--325

EN

Results and conclusions of interlaboratory comparison of indoor radon in 2015 in Serbia are presented. The participants were three accredited laboratories from Serbia: Serbian Institute of Occupational Health “Dr Dragomir Karajović”, Laboratory for Radioactivity and Dose Measurements at the Faculty of Sciences, University of Novi Sad and Radiation and Environmental Protection Department, Vinča Institute of Nuclear Science. The laboratories make use of the same method for radon measurement, using charcoal canisters according to US Environmental Protection Agency (EPA) protocol 520/5-87-005. Calibration of detection efficiency was performed using EPA radium standard. Radon activity concentrations were determined on the basis of the intensity of short-living radon daughters, 214Bi and 214Pb, gamma lines. The results of intercomparison were evaluated by using the u-test, which was calculated according to the International Atomic Energy Agency criteria. In this paper, not only limitations but also the advantages and possibilities of application of this method for measuring levels of human exposure to radon are discussed

6

Preliminary results of radon survey in thermal spas in V4 countries

Műllerová M., Mazur J., Blahušiak P., Grządziel D., Holý K., Kovács T., Kozak K., Nagy E., Neznal M., Neznal M., Shahrokhi A.

Nukleonika

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2016

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Vol. 61, No. 3

303--306

EN

Radon concentration was measured in 11 thermal spas in Visegrad countries (Czech Republic, Hungary, Poland, and Slovakia). The results showed that in 84% of spas radon activity concentration is less than 400 Bq·m–3. However, areas with radon activity concentration exceeding 1000 Bq·m–3 were found in the Czech Republic and Slovakia as well. Preliminary analyses indicated that the highest radon activities in spas were found in places with thermal pools. Radon concentration in waters used in spas ranged from 0.5 Bq/l to 384 Bq/l. The influence of radon activity concentration in water on radon activity in the air inside the spa was observed. It was found to increase indoor radon with increasing radon in the waters. Correlation with indoor radon and radon in water was more significant for baths and less significant for pool waters. In the cases filling of the bath from water taps, significantly contribute to the increased radon was observed in the pool and bath areas of the spa.

7

Radon and remediation measures near Băiţa-Ştei old uranium mine (Romania)

Cosma C., Cucoş A., Papp B., Begy R., Dicu T., Moldovan M., Truţă L., Niţă D., Burghele B., Suciu L., Sainz C.

Acta Geophysica

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2013

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Vol. 61, no. 4

859--875

EN

Băiţa-Ştei mine is an open pit mine in NW Romania (West Carpathian Mountains). It was the largest surface uranium deposit in the world. Two means of uranium transport and dissemination were used over time. The first was the natural way, represented by transportation of geological sediments by Crişul-Băiţa River that crosses the Băiţa surface deposit. These sediments were used as building materials (stone, gravel, sand). The second way was related to the people living in this valley, who used also the uranium waste as building material. The preliminary indoor radon concentrations measured in the buildings ranged from 40 to 4000 Bq m−3 with a mean value of 241 Bq m−3. A focused radon survey facilitated the selection of 20 houses with the highest indoor radon that were therefore proposed for remediation. To find the radon sources of these houses, systematic investigations on radon were performed. The remedial measures for these 20 houses were tested on a chosen pilot house.

8

The indoor radon survey in Serbian schools: can it reflect also the general population exposure?

Žunić Z. S., Bossew P., Veselinović N., Bochicchio F., Carelli V., Vaupotič J., Čuknić O., Simović R., Vojinović Z., Kisić D, Tollefsen T.

Nukleonika

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2010

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Vol. 55, No. 4

419-427

EN

A systematic indoor radon survey in elementary schools of Serbia is underway since 2008. Its current first phase covers all elementary schools in predominantly rural communities of Southern Serbia. The design of the survey, its implementation and the current state of its realization is shortly described. Part of this paper is devoted to discussion of the question if this survey could produce results representative also of the radon concentration in dwellings and of radon exposure of the general population, discussing some statistical aspects of representativity which arose during the work, namely, if the implementation leads to an unbiased estimate of the targeted quantities.

9

Evaluation of radon risk for Białystok inhabitants regarding the type of town buildings

Karpińska M., Kapała J., Szpak A., Mnich Z.

Nukleonika

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2010

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Vol. 55, No. 2

213-217

EN

Radon and its short-lived disintegration products are the most significant factors of exposure to ionizing radiation from natural sources. Białystok has the population of about 300,000 inhabitants in 100,460 flats in 16,282 houses. They are mostly one-family houses (about 80.7per cent) and two-family houses (8.2 per cent). It can be estimated that about 2/3 of the Białystok inhabitants live in the so-called “blocks of flats”. The study aimed at evaluation of the exposure to radon present in the flats. The integral method of trace detectors was used to measure radon concentration indoors. All values of the radon concentration were the mean annual values as they were obtained on annual exposure or were calculated and corrected to annual exposure based on shorter periods of time. Radon concentration distribution in flats of 3 housing estates in Białystok was analyzed. The effective dose of inhaled radon per a statistical inhabitant of Białystok (about 1.1 mSv) per year was calculated on the basis of mean values of radon concentration. Inhabitants of one-family houses obtained slightly higher annual doses – 1.4 mSv while the inhabitants of block of flats got lower annual doses – 0.8 mSv.

10

Ground and indoor radon measurements in a geothermal area

Seyis C., Inan S., Streil T.

Acta Geophysica

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2010

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Vol. 58, no. 5

939-946

EN

Geothermally active sites compared to a relatively passive site (no geothermal activity( contain much higher radon in the soil. As expected, the maximum soil radon content is at or near the major fracture zone where hot water emanates to the surface. Thus, buildings in geothermal sites nearby or at top of cracks that facilitate hot-water transfer to the surface may be extremely dangerous in terms of high radon concentrations and this situation may pose a big threat for the inhabitants. Controlled aeration of such high-risk buildings must be carefully and continuously conducted.

11

Stężenie radonu na wybranych obszarach Suwalszczyzny

Karpińska M., Wołkowicz Z., Mnich Z., Zalewski M., Mamont-Cieśla K., Antonowicz K., Kaczmarek M., Kapała J.

Przegląd Geologiczny

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2002

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Vol. 50, nr 6

521-525

PL

Przeprowadzono pomiary stężenia radonu wewnątrz budynków mieszkalnych zbudowanych na dwóch typach podłoża: piaszczysto-żwirowym i gliniastym. Pomiary przeprowadzono całkującymi detektorami śladowymi, użyto folii CR-39. Przeprowadzono również w obrębie obu wydzieleń litologicznych pomiary stężenia radonu w powietrzu glebowym. Średnia arytmetyczna stężenia radonu w powietrzu piwnic na podłożu piaszczysto-żwirowym wynosiła 276 Bq m-3, a na podłożu gliniastym 587 Bq m-3. Średnia arytmetyczna stężenia radonu w powietrzu glebowym podłoża piaszczysto-żwirowego wynosi 39,77 kBq m-3 a podłoża gliniastego 26,66 kBq m-3. Stężenie radonu w wodzie studziennej (8367 Bq m-3) było wyższe na całym badanym terenie w porównaniu ze stężeniem w wodzie wodociągowej (2690 Bq m-3).

EN

Measurements of radon concentrations in indoor air were carried out in dwellings built on two types of soil, i.e. sandy -gravel soils and clay soils. An integrative method of a-track film was used. The radon measurements in soil air were performed for both types of soils. The arithmetic mean of radon concentration in cellar air within gravel-sandy soil was 276 Bq m^-3, whereas within clay soil - 587 Bq m^-3. In turn, these value in soil air in sandy-gravel area reached 39.77 kBq m^-3, whereas in clay soil - 26.66 Bq m^-3 The concentration of radon in the household well water in the whole examined area was higher (8367 Bq m^-3) compared to that " water from supply system (2690 Bq m^-3).