exposure, for 39sr, 140ga, 1311, the rare earth group, and fissile material. As expected, the Rongelap people had the highest body burdens. By 6 months, beta activity in the urine samples was barely detectable. Table 2 shows the main isotopes found at day 1 (extrapolated values) and at day 82. The agreement between the findings at the two laboratories is close considering the techniques available at that time. Levels in the Ailingnae group were about one-half and in the Americans about one-quarter the levels in the Rongelap group. Only isotopes of iodinc, strontium, barium, and a few rare earth elements were detected in any significant degree. Im the Rongelap group, at day 1, 89sr and 131] were near the maximum permissible levels, and the estimated total amount of radioactive material in the gastrointestinal tract was about 3 mCi; whether this had any relation to the early gastrointestinal symptoms is not known. Table 2. Estimated body burden (yCi) of Rongelap people. Activity* at day l 89s, 14GR4 Rare earth group 131y (in thyroid gland) O3Ru 45¢a Fissile material 1.6 - 2.2 0.34- 2.7 Oo -1.2 6.4 -11.2 0 - 0.013 Qo QO Max. perm. Activity** at day 8&2 - 0.019 - 0.016 Cig) total body burden 0.19 0.021 40 9 0.03 - 0.0 Q.0 , 0.7 50 200 0.4 *From U.S. Naval Radiological Defense Laboratory. **From Los Alamos Scientific Laboratory. The total whole-body or bone~marrow dose from the absorbed nuclides was not calculated because of the variety and waried etergies of these radiations. However, the dose is thought to have been quite small compared with the whole-body ganssa dose. 5. Thyroid Doses* The fallout produced several possible sources of radiation exposure to the thyroid gland. The gamma radiation resulted ia thyroid doses of 175 rads in the Rengelap people, 69 rads in the Ailingnae people, and 14 rads in the Utirik group. Iodine isotopes are produced in relatively high yields by the *See second footnote at beginning of this Appendix. - 112 -