4 3 (5) Effects on Food Chains The residual radioactivity which has existed in the environs of the atoll for approximate ly twenty years has undoubtedly penetrated all food webs of atoll ecosystems. In the absence of detailed radiological data it is not possible to state the amounts in any food chain but it is likely that concentrations of several radioactive species are sufficiently high to contribute amounts of radioactivity to man through his diet which are of potential significance to human health. Both bone seeking iso- topes and radioactive species which distribute uniformly throughout tissue are present. Long-lived iodine-129, will likely not be a problem of great concern. Meaningful assessment of the consequences of plutonium and other transuranics in the food chain as well as quantitative information or the contribution of radioactive fission and activation products in important food chains will have to await radiological survey results. It is unlikely, however, that concentrations are sufficiently high, even in the most highly contaminated areas of the atoll to cause disruption of food chains by radiation damage to components. Data from the radiological survey on several components of major food chains to man will be evaluated and available towards the end of May. The proper assessment of radionuclide transfer through the food web to the natives will have to wait on analyses of samples collected to date. However, even though consensus believes no overt genetic and somatic damage will occur to the natives due