Keywords
uranium
klint
graptolite argillite
Quaternary deposits
till
How to Cite
Abstract
The risk of dangerous radon emissions in Estonia is high, being among the highest in Europe. In almost 33 per cent of Estonian land area, the content of radon in soil-contained air exceeds the safe limit for unrestricted construction (50 kBq/m3). In such high radon-risk areas the concentration of radon in soil-contained air ranges from 50 to 400 kBq/m3, in a few cases reaching up to 2,100 kBq/m3 exceeding the permitted level for residential areas. The situation is particularly serious in the northernmost part of the country, where uranium-rich graptolite argillite (Dictyonema shale) and the Obolus phosphorite are close to ground surface and their particles are constituent parts of Quaternary deposits. Radon emissions from bedrock have been investigated in detail, but to date Quaternary strata as a source of radon emissions are poorly studied. According to our measurements the highest concentrations of radon are related to tills containing clasts and fines of graptolite argillite and phosphorite. Glacial deposits include also granitoidal material, containing U, Th and K, which have been transported by glaciers from the outcrop areas of crystalline basement rocks in Finland and the Gulf of Finland. Due to weathering, outwash and repeated redeposition other genetic types are poorer in radioactive elements and they are weaker sources of radon.
References
Andersson, A., Dahlman, D., Gee, D.G. & Snäll, S., 1985. The Scandinavian alum shales. Sveriges Geologiska Undersökning Ca 56, 1-50.
Åkerblom, G., 1994. Ground radon - monitoring procedures in Sweden. Geoscientist 4, 21-27.
Bochicchio, F., 2005. Radon epidemiology and nuclear track detectors: Methods, results and perspectives. Radiation Measurements 40, 177-190.
Clavensjö, B. & Åkerblom, G., 1994. The Radon book. Measures against radon. The Swedish Council for Building Research, Stockholm, 129 pp.
Estonian Centre for Standardisation, 2009. Estonian Standard 840:2009. Design of Radon-Safe Buildings. Estonian Centre for Standardisation, 20 pp. [in Estonian].
Ivanov, V.V., 1994. Èkologičeskaja geohimija èlementov. Kniga 1. Spravochnik [Ecological geochemistry of elements]. Èkologija, Moskva, 305 pp. [in Russian].
Jüriado, K. & Petersell, V., 2010. Relationship between the concentration of radon directly measured in soil air and calculated after radium. [In:] I. Barnet, M. Neznal & P. Pacherová (Eds): 10th International Workshop on the Geological Aspects of Radon Risk Mapping. Czech Geological Survey, Prague, 148-156.
Jüriado, K., Petersell, V. & Raukas, A., 2014. Seasonal variations of radon concentration in soil air in different geological conditions on the example of Estonia. Geologija 56, 4, 87-97.
Jüriado, K., Raukas, A. & Petersell, V., 2012. Alum shales causing radon risks on the example of Maardu area, North Estonia. Oil Shale 29, 76-84.
Kessel, H.J. & Raukas, A., 1967. The deposits of the Ancylus Lake and Littorina Sea in Estonia. Valgus, Tallinn, 135 pp. [in Russian, with English summary].
Kiipli, T., 2005. Biogeokeemiline uuring Viljandi ja Tartu piirkonnas [Biogeochemical study in Viljandi and Tartu regions]. [In:] M. Kukk (Ed.): Eesti Geoloogiakeskuse aastaraamat 2004 [Annual of the Geological Survey of Estonia 2004]. Geological Survey of Estonia, Tallinn, 30-33.
Koljonen, T. (Ed.), 1992. The Geochemical Atlas of Finland. Part 2. Till. Geological Survey of Finland, Espoo, 218 pp.
Miidel, A., Raukas, A., Tavast, E. & Vaher, R., 2006. Influence of bedrock topography on oil shale mining in North-East Estonia. Oil Shale 23, 313-327.
Pahapill, L., Jõgioja, E. & Rohumäe, T., 1993. Indoor radon in Estonia. International Conference on Indoor Air Quality and Climate 4, 471-474.
Pahapill, L., Rulkov, A., Rajamäe, R. & Åkerblom, G., 2003. Radon in Estonian Dwellings. Results from a National Radon Survey. SSI raport: 2003:16. Swedish Radiation Protection Authority, Estonian Radiation Protection Centre, Stockholm, 20 pp.
Petersell, V., Mõttus, V. & Täht, K., 2006. Ida-Virumaa radooniriski kaart, M 1:200000 [Radon Risk Map of Ida-Virumaa at scale of 1:200000]. Geological Survey of Estonia, Tallinn, 29 pp. [in Estonian].
Petersell, V., Täht-Kok. K. & Karimov, M., 2008. Harjumaa radooniriski kaart, M. 1:200000 [Radon Risk Map of Harjumaa at scale of 1:200000]. Geological Survey of Estonia, Tallinn [in Estonian].
Petersell, V., Shtokalenko, M., Täht-Kok, K. & Talpas, A., 2013. Kirde-Eesti tööstuspiirkonna pinnase (muldade) keskkonnaseisundi uuringute aruanne [Report of the study of environmental condition of soils in the industrial area of north-eastern Estonia]. Geological Survey of Estonia, Tallinn, 111 pp. [in Estonian].
Petersell, V., Åkerblom, G., Ek, B.-M., Enel, M., Mõttus, V. & Täht, K., 2005. Radon Risk Map of Estonia: Explanatory text to the Radon Risk Map Set of Estonia at scale of 1:500 000 Report 2005:16. Swedish Radiation Protection Authority, Tallinn, 76 pp.
Raukas, A., 1961a. Mineraloogilise meetodi kasutamise võimalusest moreenide uurimisel Eestis [Application of the mineralogical method to the investigation of tills in Estonia]. ENSV Teaduste Akadeemia Geoloogia Instituudi Uurimused. Antropogeeni geoloogia 7, 55-67 [in Estonian with Russian and English summaries].
Raukas, A., 1961b. Mineralogia moren Estonii [The mineralogy of the Estonian tills]. Eesti NSV Teaduste Akadeemia Toimetised. Füüsikalis-matemaatiliste ja tehniliste teaduste seeria 10, 3, 244-258 [in Russian with English summary].
Raukas, A., 1969. Composition and genesis of Estonian tills. Uniwersytet im. Adama Mickiewicza w Poznaniu. Seria Geografia 8, 167-176.
Raukas, A., 1978. Pleistotsenovye otloženia Estonskoi SSR [Pleistocene deposits of the Estonian SSR]. Valgus, Tallinn, 310 pp. [in Russian with English summary].
Raukas, A., 1995. Properties, origin and stratigraphy of Estonian tills. [In:] J. Ehlers, S. Kozarski & P.L. Gibbard (Eds): Glacial deposits in North-East Europe, Balkema, Rotterdam, 93-101.
Raukas, A. & Gaigalas, A., 1993. Pleistocene glacial deposits along the eastern periphery of the Scandinavian ice sheets - an overview. Boreas 22, 214-222.
Raukas, A. & Tavast, E., 1987. Eesti mattunud orgude ehitusest. [On the structure of buried valleys in Estonia]. Eesti Geograafia Seltsi aastaraamat 1981/1982 20, 5-15 [in Estonian with Russian and English summaries].
Raukas, A., Koch, R., Jüriado, K. & Järvelill, I.J., 2014. Anomalous radioactivity level and high concentrations of heavy minerals in Lemme area, South-West Estonia. Baltica 27, 2, 93-103.
Stankowski, W. (Ed.), 1976. Till, its genesis and diagenesis. Uniwersitet im. Adama Mickiewicza w Poznaniu. Seria Geografia 12, 266 pp.
Suuroja, K., 2006. Põhja-Eesti klint - Eesti looduse sümbol [North-Estonian Klint - Symbol of Estonian nature]. Keskkonnaministeerium, Tallinn, 224 pp. [in Estonian].
UNSCEAR, 1993. United Nations Scientific Committee on the Effects of Atomic Radiation. Report to the General Assembly, with scientific annexes. United Nations, New York, 922 pp.
Vaher, R., Miidel, A., Raukas, A. & Tavast, E., 2010. Ancient buried valleys in the city of Tallinn and adjacent area. Estonian Journal of Earth Sciences 59, 37-48.
Vares, K. & Raukas, A., 1981. The Estonian soil-forming rocks. Eesti NSV Teaduste Akadeemia Toimetised. Geoloogia 30, 125-132 [in Russian with English and Estonian summaries].
Wedepohl, K.H., 1995. The composition of the continental crust. Geochimica et Cosmochimica Acta 59, 1217-1232.
World Health Organization (WHO), 2009. WHO handbook on indoor radon: a public health perspective. WHO, Geneva, 94 pp.
License
Copyright (c) 2015 Valter Petersell, Krista Jüriado, Anto Raukas, Mihkel Shtokalenko, Krista Täht-Kok
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 Unported License.