Terrestrial radiation (radionuclides)

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Terrestrial radiation is ubiquitous radiation - mainly gamma radiation - caused by radionuclides in the ground that were formed billions of years ago by stellar nucleosynthesis and have not yet decayed due to their long half-lives . This includes in particular

  • Thorium -232 (half-life 14 billion years),
  • Uranium -238 (half-life 4.4 billion years),
  • Uranium-235 (half-life 0.7 billion years) and
  • Potassium -40 (half-life 1.3 billion years).

Added to this are their radioactive decay products such as gaseous radon , which can escape from the ground and be inhaled. In these cases, the alpha and / or beta radiation is also effective as radiation exposure .

The terrestrial radiation is thus emitted by the natural radionuclides in the soil, rocks and the air. These are contained in almost every building material and are also released when coal is burned . The coal used annually for power generation worldwide contains around 10,000 t of uranium and 25,000 t of thorium .

Like all ionizing radiation , terrestrial radiation can also have a damaging effect on living cells by causing cancer or by changing or destroying genetic material .

The dose rate of the radiation is given in mSv / a ( millisievert per year). In Germany, terrestrial radiation causes an average radiation exposure of around 0.4 mSv / a, a quarter of this from being outdoors and three quarters from being in buildings, although the values ​​can vary widely from region to region. The highest values ​​are found in the Ore Mountains , the Bavarian Forest and other low mountain ranges (up to 1.3 mSv / year), the lowest in northern Germany (approx. 0.25 mSv / year). In other regions of the world, however, it can be significantly higher with peak values ​​of over 200 mSv per year (in Ramsar , Iran).

Radiation exposure from gaseous nuclides that are inhaled is considered particularly dangerous (see Schneeberger disease ).

Individual evidence

  1. http://www.world-nuclear.org/info/inf30.html
  2. How high is the natural radiation exposure in Germany?
  3. ^ Norbert Krappitz: Handbook of travel medicine health advice . Deutscher Arzte-Verlag, 2009, ISBN 978-3-7691-1270-2 ( limited preview in Google book search).
  4. ^ Johannes Friedrich Diehl: Radioactivity in food . John Wiley & Sons, November 21, 2008, ISBN 978-3-527-62374-7 , p. 54.