Radiation Protection Glossary
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Radioactive can generally describe the property of a substance (or more accurately atomic nuclei) which are unstable and spontaneously Decay
(disintegrate) with the release of energy, the energy being either Electromagnetic Radiation
, particulate or both. This process may occur in both naturally occurring radioactive material and man made substances. For any given element there will be a number of Isotopes
, some of which may be radioactive. The point at which a substances can be said to be radioactive requires careful interpretation of law and may depend on particular circumstances. For example, in the UK, material with an Activity
< 0.4 Bq / g is not considered radioactive (Radioactive Substances Act 1993