1. Food webs - It should be recognized that the food webs are not perfectly known, buf to move beyond what is now known would require a major effort that probably is not needed for this program, at least for the gamma-emitting radionuclides. Held has described the food web relationships for gamma-emitting radionuclides in the figure, "Distribution of Fallout Radioisotopes, Rongelap Atoll, 1061," a copy of which is attached. From information obtained at Bikini and Eniwetok since 1961, there is no reason to expect that there would be any major surprises if the 1961 Rongelap model was used as the 1973 Eniwetok model. Held's work did not include analyses for alpha-emitting radionuclides and hence the food web studies at Runit need special attention. 2. Models - The use of models for quantitative estimates of the movement of radionuclides through the food web will be limited by the scanty information on transfer coefficients. 3. Limits of detection - The limits of detection should be established on the basis of their effects on the estimates of the total dose to the Eniwetekese. 4. Number of radionuclides - Undoubtedly, there are a few radionuclides in the samples that can be identified by use of involved chemical procedures and/or sophisticated instruments. Although a complete budget of all radionuclides present in the samples is of great academic interest, such information is being obtained from Bikini and, therefore, for practical reasons, the decision to seek out these radionuclides should rest on their contribution to the total dose. 3» Number of samples for specific radionuclides - All samples did not need to ‘be analyzed for ail radionuclides. The information from previous analyses and the use of indicator species should guide the decision about number of samples for specific radionuclides. In regard to execution of the program, my observation based on the December trip to Eniwetok and our Laboratory's contract with LLL is that the program has been well executed. Sincerely yours, AHS:ah ~ cc: Dr. Edward Held aS CD Csi o> Le ory —! Enc. A Allyn H. Seymour Director, Laboratory of Radiation Ecology