Radioactive Fallout

Radioactive fallout is material produced by a nuclear explosion or a nuclear reactor accident that enters the atmosphere and eventually falls to Earth. This fallout consists of minute, radioactive particles of dust, soil, and other debris. While some fallout results from natural sources, the term is usually used in reference to radioactive particles that were released into the atmosphere by a nuclear explosion or reactor accident. Fallout refers to material that has fallen to Earth, and also to material that is still suspended in the atmosphere.