natural radioactivity

https://doi.org/10.1351/goldbook.N04092
Radioactivity
of naturally occurring
nuclides
in materials where the
isotopic abundance
of that
nuclides
is natural.
Source:
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1546 [Terms] [Paper]