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Environmental Earth Sciences

, Volume 69, Issue 5, pp 1601–1607 | Cite as

Increased soil gas radon and indoor radon concentrations in Neoproterozoic olistostromes of the Teplá-Barrandian unit (Czech Republic)

  • Ivan BarnetEmail author
  • Petra Pacherová
Original Article

Abstract

The Neoproterozoic olistostromes were first distinguished as a special geological unit in a generalised geological map of the Czech Republic on a scale 1:500,000. The olistostromes represent a tectonic mélange or subaquatic continental slope-slides formed by a mixture of black shales, greywackes, carbonates and shales, forming an extremely inhomogeneous geological environment. The extreme over-limit values of indoor radon (Rn, 222Rn) were first detected during check measurements performed for final building approval by team of the National Radiation Protection Institute in a house situated on bedrock of black shales—lithological component of olistostromes north-eastward from Plzeň. Additional measurements of soil gas Rn performed by the Czech Geological Survey were oriented to cover the whole olistostrome belt extending over 65 × 25 km area NE of Plzeň–Prague general direction. The increased concentrations both of soil gas and indoor Rn were confirmed in the whole extent of Neoproterozoic olistostrome belt compared to neighbouring geological units (Neoproterozoic metasediments on NW and Cambrian Palaeovolcanites and Ordovician sediments on SE). This observation lead to increasing the radon index of olistostromes to medium radon category (from the low one) both in general and detailed Rn index maps. Drawing the attention to this lithological type enables to improve the radon risk prevention for newly built houses and interest of remediation of existing houses not only in the specific area of the Czech Republic, but also in other European countries, where Neoproterozoic olistostromes form the geological basement.

Keywords

Neoproterozoic olistostromes Soil gas radon Indoor radon Extreme concentrations Teplá-Barrandian unit Bohemicum 

Notes

Acknowledgments

Department of Geology, Ministry of Environment, is thanked for funding the project 630100, oriented to actualization of radon index maps. This project followed the Action plan of the Radon Programme of the Czech Republic. The authors are grateful to colleagues from the NRPI for sharing and interpretation of indoor data from the studied area.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Czech Geological Survey Klarov 3Prague 1Czech Republic

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