Biological concentration of 3H

In a three-year study, the possible biological concentration of 3H in rabbits was investigated. Tritiated water was used to grow alfalfa that was used exclusively as feed for the rabbits. Feed and water were kept at a constant 3H-to-1H ratio. The foundation group consisted of 18 female rabbits maintained on a 3H diet for 2 wk before mating. The subsequent generations were maintained with tritiated water and feed. At appropriate intervals, animals were sacrificed and selected tissues were analyzed for 3H. The specific activity of 3H in aqueous and organic fractions of tissues of all the animals remained essentially equal to that in the original water and feed. Results of this experiment indicate that under the steady-state equilibrium conditions of the experiment, no preferential concentration of 3H in animals occurred.