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Ionising radiation

Environmental Radioactivity - Medicine - Occupational Radiation Protection - Nuclear Hazards Defence

Ionisierende Strahlung

Radon in the soil

  • The radon arising in the soil partly reaches the surface and is released into the atmosphere.
  • The exhalation rate strongly depends on the permeability of the soil and weather conditions (temperature, humidity, air pressure).
  • Radon can also be dissolved in ground water and migrates in bedrock.

radon, soil air, transport Transport of Radon in soilTransport of Radon in soil

Part of the radon originating from the decay of radium located in rocks and soil particles is emitted in the pore volume of soil and stones. Due to atmospheric conditions (temperature, air pressure, weather), the radon concentration in a depth of less than one meter varies considerably. With increasing depth, the radon concentration rises to a saturation value.

The permeability of the soil plays a decisive role. Generally, starting from a depth of one meter, the radon concentration in the soil air changes only in a minor way. Due to the half-life (circa 1,600 years) of Radium-226, the parent of radon, the radon soil air concentration is stable over a long term. If the radon concentration of a particular site is known, new measurements are only necessary after significant interventions done in the underground.

Cracks and rifts simplify the transport of radon in the underground. Therefore the local radon concentration can be much higher in the proximity of chasms, subsidences or boundaries between different rocks.

Furthermore, radon can be dissolved in groundwater and transported through the geological underground.

The radon map

State of 2017.09.29

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