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Ionising radiation

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

Ionisierende Strahlung

Effects of selected radioactive substances

Radioactive substances interact with the human body, each with its specific way which depends on occurrance and physical properties. Based on examples for selected substances, this interaction is explained.


Plutonium (Pu) is a heavy metal with the atomic number 94. For the human body it is chemically toxic as some other heavy metals like lead and mercury. Additionally, plutonium is radioactive, which means that its various nuclides emit radiation during decay. The half-life of plutonium nuclides is rather long, for example for plutonium-239, it takes 24,110 years until half of the atomic nuclei have decayed. During radioactive decay, mainly alpha radiation is emitted and - to a far lesser extent - also gamma radiation.

Health effects

Radon can accumulate in the ambient air of closed rooms. Particularly harmful are its short-lived progeny which can deposit in the respiratory tract. Alpha radiation that accrues during decay can promote lung cancer. According to statistical risk calculations, nearly 1,900 deaths yearly are due to indoor radon in Germany. Within the European Union, 20,000 deaths yearly can be attributed to indoor radon.


The physical and chemical properties of uranium are described. In principle, there are two health effects of uranium to be considered: health effects due to the metal properties of uranium (chemotoxic effects) and health effects due to radiation properties of uranium (radiotoxic effects).

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