b. Quite unlike physical measurements, definitive which have a end point that can be measured at a Single observation, biological processes are constantly changing and it is only through continuous or repeated observations that the problems can be evaluated. c. The time factor in biological studies of this sort is often little appreciated and it is only after the lapse of sufficient time that many effects become obvious. dad. The data collected over a period of years will deter- mine if the selection and retention of radioactive material in a natural environment as at Bikini and Eniwetok are transitory phenomena or if there will tend to be a balance at some level with these materials in equilibrium. e. Studies of the so-called insoluble, non-available isotopes at Bikini and Eniwetok should be made. example, For zr95 was found in the soft parts of fish, > although the principal fission product ZrO, is insol- uble except in sulphuric or hydrofluoric acid. 3y, S. Atomic Energy Commission report, OC-155 (Classified) It