10 rads. Calculation of the dosage from radioiodines unfortunately had to be based ona single, pooled urine sample from Rongelap people collected 15 days post exposure. Harris?” at Los Alamos had reported a low level of 1211 in this sample and had calculated a one-day thyroid content of 11.2 uCi based on the assumption of 0.1% urinary excretion of the maximumthyroid burden on the 15th day. S Thyroid wt (g) =. James calculated doses for absorption from both inhalation and ingestion. He noted thatthe shorterlived isotopes of iodine delivered 2 to 3 times the estimated dose delivered by !31I alone. The importance of these shorter-lived isétepes in producing thyroid effects in the Marshallese will be referred to in Section IV. The dosé to fethyroid of a Rongelap adult (including gamma) was cal- culated as about 335 rads (220 to 450 rads) and to that of a 3-year-old Rongelap child as 700 to 1400 s. (The spread is due to uncertainties in estimating dose from absorption of radioiodines by -ginhalation versus ingestion.). With the assumption “that the ratio of whole-body gammadosesto thvroid doses was the same as for the Rongelap people, James’ calculations were used to estimate thyroid doses in the Ailingnae and Utirik groups; the results were 135 rads for the Ailingnae adults and 27 rads for the Utirik adults. The children’s thyroid doses were based on the weight of the gland at various ages (Figure 3).28 By using a linear relationship betweenthe thyroid size and the dose calculated by James, the doses to individual children were taken from regression lines drawn for the three exposed populations (Figure 4); these are given in Section IV. In retrospect, the Figure 3. Weights of human thyroids in New York City. (From Mocnizuxi et aL.?8) estimated average dose of 1050 rads to the thyroids of young children appears to be low, at least for two boys who developed atrophy and myxedema. The calculated doses are obviously rough estimates. The incompatability of the observed effects with the calculated doses based on 131] must be related partly to the greater dose effect of shortlived iodine isotopes (see Appendix 9C). 7-2 Thyroid dose (rads) 1400 oc TJ TT TT TT ot oo, ad +> —~: be ¥ x + fot 1000 + 4% L Rongelap 500K ; Ailingnae 7 = 4 bE — P q peered 0 i Utirik i 1 L 3 i 4, _ Lt 10 i5 T_. 20 Age Figure 4. Thyroid dose versus age for children in exposed Marshallese groups. —% B. ACUTE EFFECTS - 1. Bilocts of Whole-Body Exposure He arly Symptoms. Duringthefirst two days, . “before evacuation, symptomsrelated to the skin and the gastrointestinal tract were noted in a large numberof Rongeiap people, in a lesser number among the groups exposed on Ailingnae and Rongerik, and in noneof the Utirik group. The severity of the symptoms was correlated with the amountof fallout and the radiation dose. Skin symptoms(itching and burningof areas not covered by clothing) were noted in about one-fourth of the Rongelap people, and a few complained of irritation of the eyes and lachrymation. These symptoms were thoughtto be related to betairra-