There are three forms of radioactivity :

• Alpha decay in which the nucleus of a helium atom is emitted
• Beta decay occurs when an electron is emitted
• Gamma decay emits a photon of electromagnetic radiation

There is no limit to the amount of radiation below which there is no damage to living ceatures. The extraction of radioactive materials and their use for civil and military purposes incurs the cost of this damage. Radioactivity can persist for seconds or for long periods, in some cases for millions of years. The rate at which the activity declines cannot be altered.

Mining and processing of nuclear material inevitably result in the release of particles which contaminate the surroundings. Nuclear power stations discharge effluent into the sea, land and air. After use radioactive material has to be kept in isolation until the activity has reduced sufficiently for it to be placed in some permanent depository. An explosion of a nuclear plant can result in radioactive material bieng spread over a wide area. The explosion at Chernobyl in the Ukraine in 1986 caused the contamination of most of Europe. A nuclear explosion causes the release of large doses of radiation and if it takes place at ground level the soil taken into the air forms a radioactive cloud which can be carried over hundreds of miles.

Short-term radiation effects
Long-term radiation effects
Effects of radiation on the body

Related Websites

Atomic Archive
has a timeline starting in the 1930s, a glossary with relevent terms, photographs, info on world nuclear forces + nuclear stockpiles, explanation of nuclear fusion and fission, a teacher's guide, maps, an example scenario of what would happen if a bomb was dropped on new york, biographies of key players of the atomic age.