What is the half-life?
Martina Feichter studied biology with an elective subject pharmacy in Innsbruck and also immersed herself in the world of medicinal plants. From there it was not far to other medical topics that still captivate her to this day. She trained as a journalist at the Axel Springer Academy in Hamburg and has been working for since 2007 - first as an editor and since 2012 as a freelance writer.
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Radioactive substances disintegrate at different rates, which is expressed by the half-life. It indicates the time span in which half of a radiating substance has decayed. The radioactive iodine used in medicine has a relatively short half-life (131 iodine): It takes a little more than eight days for half of the administered dose to break down. Plutonium, on the other hand, has a half-life of 24,000 years. Of particular concern, therefore, is the fact that one of the Rectors of Fukushima also contains plutonium.
The half-life does not indicate how long it takes for a radioactive material to be harmless. Even if half of the substance has already decayed after the half-life, the second half continues to radiate. However, the decay process is not linear. It is therefore difficult to determine when exactly the radioactive substance no longer poses a hazard.
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