Tritium dynamics in mice exposed to tritiated water and diet

The contributions of tritiated water (3HHO) and dietary tritiated amino acids to the steady-state specific activities of tissue water tritium and organically bound tritium in mice were essentially independent and additive. Following exposure (56 d), organically bound tritium clearance was resolved into two distinct compartments. The first, with a half-life of 1-2 d, likely represented exchangeable organically bound tritium, and the second, with a half-life of 20-30 d, likely represented nonexchangeable organically bound tritium. Since organically bound tritium was cleared much more slowly than tissue water tritium, organically bound tritium was the principal determinant in estimated radiation doses to mice following exposure.