4. Tritium and carbon-14 transfers

Transfers of tritium and carbon 14 in food chains are different from transfers of other radionuclides presented earlier in this article, as they are isotopes of the major elements hydrogen and carbon, which are constituents of water (for tritium) and organic matter (for tritium and carbon 14).

The tritium present in a water molecule, HTO, also known as "free tritium", exchanges rapidly and permanently with the two stable isotopes of hydrogen, in particular protium ( ¹ H), which is the most abundant (99.985% by mass); in the environment, HTO follows the water cycle.

Tritium and carbon-14 present in the air become constituents of organic matter through photosynthesis, and thus follow the organic matter cycle. Tritium associated with organic matter is known as TOL, for "tritium organically bound"....