Fallout

scroll

Radioactive material which falls back to the earth after the release into the atmosphere (e.g. by nuclear weapon tests, accidents). The fallout occurs in two forms: the close fallout consists of heavy particles which fall to the ground within some days near the place of release and in an area which, depending on the weather conditions, may reach up to several hundred kilometres in the wind direction. The world-wide fallout consists of lighter particles reaching higher atmospheric layers and distributed over a wide part of the earth because of atmospheric currents. These particles eventually come down to the ground, mainly with precipitations, over periods of between months and several years. For example in the 60s, the radiation exposure in Germany caused by the fallout of nuclear weapon tests amounted to 0.1 to 0.4 mSv per year. At present it is less than 0.01 mSv per year; the overall dose in the period from 1960 to 2010 is estimated to be 2 mSv. The radiation exposure by the fallout due to the reactor accident in Chernobyl amounted to about 2 mSv for persons in Germany living south the Danube and in the rest of Germany about 0.6 mSv in the period from 1986 to 2030.

back