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1

Thoron emanation and exhalation of Slovenian soils determined by a PIC detector-equipped radon monitor

Jónás J., Sas Z., Vaupotic J., Kocsis E., Somlai J., Kovács T.

Nukleonika

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2016

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Vol. 61, No. 3

379--384

EN

The health risk from thoron (Rn-220) is usually ignored owing to its short half-life (55.6 s), but the generated thoron decay products can cause a significant dose contribution. In this study, altogether 51 Slovenian soil samples were investigated using an accumulation chamber technique to obtain information about thoron exhalation features. The obtained (massic) thoron exhalation results varied between 6.9 and 149 mBq•kg–1•s–1 (average: 55.2 mBq•kg –1•s–1). The Th-232 content was determined using HPGe gamma spectrometry. The Th-232 activity concentration ranged between 9.3 and 161.7 Bq•kg–1 (average: 64.6 Bq•kg –1). The thoron emanation features were also calculated from the obtained results (2.9 to 21.2% with an average of 8.6%). The thoron exhalation and emanation properties were compared with the radon exhalation and emanation features determined in a previous study. It was found that there was no correlation between the radon and thoron emanation features, according to the obtained data. This can be explained by the different Ra-224 and Ra-226 distributions in the soil grains. As a result, the thoron emanation factor cannot be predicted from radon emanation and vice versa.

2

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.

3

Distribution of indoor radon concentrations between selected Hungarian thermal baths

Shahrokhi A., Nagy E., Csordás A., Somlai J., Kovács T.

Nukleonika

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2016

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Vol. 61, No. 3

333--336

EN

Owing to the high potential of radon to increase the risk of lung cancer, health organizations are enforced to update their regulations and recommendations regarding indoor radon levels each year. In this study, the indoor radon concentrations of three randomly selected thermal baths in Hungary using CR-39 and an AlphaGUARD radon monitor were measured with regard to the new updated standards of the European Basic Safety Standard (EU BSS, Council Directive 2013/59/Euratom, 2014). The annual average of indoor radon concentrations in Parad Medical Bath, Igal Health Spa and Eger Turkish Bath were measured as 159 ± 19, 176 ± 27 and 301 ± 30 Bq/m3, respectively. Indoor radon concentration in all measurement locations were determined to be below the reference level, with the exception of the main pool, small pool and sparkling bath areas in the Eger Turkish Bath that were measured as 403 ± 42, 315 ± 32 and 354 ± 36 Bq/m3, respectively. In light of the results, the estimated annual average radon concentration in the thermal baths was below the EU BSS reference level of 300 Bq/m3. Personal dosimetry is required to estimate the annual effective dose from inhaled radon by the workers at the Eger Turkish Bath. This procedure is required in order to justify the application of the mitigation process of decreasing working hours, improving the ventilation rate or increasing the number of classified employees in response to the official radiation surveillance programme.

4

Terrestrial radioisotopes in black shale hosted Mn-carbonate deposit (Úrkút, Hungary)

Vigh T., Kovács T., Somlai J., Kávási N., Polgári M., Bíró L.

Acta Geophysica

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2013

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Vol. 61, no. 4

831--847

EN

Previously, little attention has been paid to terrestrial radioisotopes (U, Th, 40K) occurring in manganese ores, despite the fact that the biogeochemical relationship between Mn and U is versatile. Occurrence of terrestrial radioisotopes in great amounts during mining on a long-term causes significant radiation exposure. It is important to inspect black shale-hosted manganese ores from this aspect, as black shales are typically potential U-rich formations. Despite the increased radon concentration in the mine, based on the detailed major elements, trace elements and gamma spectroscopy inspection of the rock types of deposit, the U, Th enrichment was undetectable. However, the U and Th content of about average terrestrial abundance of the great ore amount may be in the background of the increased radon concentration level. This Mn-carbonate ore deposit in spite of the low U content exhibit potential radon danger for miners, which can be eliminated with intensive air change only.

5

Radiological aspects of red mud disaster in Hungary

Kovács T., Sas Z., Jobbágy V., Csordás A., Szeiler G., Somlai J.

Acta Geophysica

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2013

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Vol. 61, no. 4

1026--1037

EN

One of the most severe industrial catastrophes happened in Kolontár, Hungary, on 4 October 2010. Red mud (bauxite residue) broke through the eroded wall of the red mud reservoir pond “Number X” and flooded the surrounding area. This led to the instant death of 10 people and the injury of more than 100 people. Red mud is enriched in radium and thorium isotopes; therefore, there is a chance that this flooding will increase radionuclide concentrations of soils and also in air. In this study we have examined the site to assess the realistic radiological risks. For the risk assessment the following parameters were determined: gamma dose rate, radon concentration, radionuclide concentration of red mud and air dust concentration. It was found that the radiation dose exposure resulting from red mud contamination was < 0.045 mSv y–1 (excluding radon), which can be considered negligible when compared to the average annual effective dose from natural sources (2.4 mSv y–1).

6

Radon and thoron parallel measurements in dwellings nearby a closed Hungarian uranium mine

Németh C., Jobbágy V., Kávási N., Somlai J., Kovács T., Tokonami S.

Nukleonika

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2010

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Vol. 55, No. 4

459-462

EN

Integrated measurements of radon (222Rn) and thoron (220Rn) were executed in a Hungarian village, located in the vicinity of an abandoned uranium mine. The applied passive radon and thoron monitor was the RADUET which is based on a CR-39 track detector. The investigated 35 houses were one storey buildings made of bricks. The rock under the village is a gray-sandstone with an average of 136 and 77 Bqźkg–1 uranium and thorium, respectively. The detectors were mostly placed in the inhabited areas of the houses, such as bedrooms and living-rooms, at a height of 1–1.5 m close to the wall. The measurement periods were between December 2006 and May 2007 and between May 2007 and February 2008. Annual averages of radon concentrations were calculated applying seasonal correction factors to the results of the two measurement periods. The results show that the radon concentrations in the case of considerable part of the investigated dwellings seems to be significantly higher than the Hungarian averages for ground-floor houses (152 Bqźm–3). The thoron concentrations in some cases are also not negligible indicating that radon measurements which are sensitive to thoron can be misleading. Additionally, thoron can also be a contributor of extra dose.