10 rads. Calculation of the dosage from radioiodines unfortunately had to be based on single, pooled urine sample from Rongelap peoplecollected 15 days post exposure. Harris?7? at Los Alamos had reported a low level of 1311 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 maximum thyroid burden on the 15th day. Jamescalculated doses for absorption from both inhalation and ingestion. He noted that the shorterlived isotopes of iodine delivered 2 to 3 times the estimated dose delivered by 1311 alone. The importance of these shorter-lived is6tapes in producing thyroid effects in the Marshallese will be referred to in fection IV. The dosé to ¥€ thyroid of a Rongelap adutt (including gamniia) 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 rags. (The spread is due to uncertainties in estiMating dose from absorption of radioiodines by -ginhalation versus ingestion.), With the assumption 20 3 Thyroid wi (g) that the ratio of whole-body gammadosesto thy- Figure 3. Weights of human thyroids in New York City. (From Mocnizuki et av.28) 1400 TTT T | T TOT UF yf TTF 7 v roy v . . Thyroid dose (rads) Le ~~. 1000 4% = 4 500 4 — 0: 0 7 Uurik pe, 5 3 et 10 tte 15 Age Figure 4. Thyroid dose versus age for children in exposed Marshallese groups. roid 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 between the thyroid size and the dose calculated by James, the doses to individual children were taken from regression lines drawn forthe three exposed populations (Figure 4); these are given in Section IV. In retrospect, the 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 !311 must be related partly to the greater dose effect of shortlived iodine isotopes (see Appendix 9C). aY 8. ACUTE EFFECTS - i Bilects of Whole-Body Exposure He:-forly Symptoms. During thefirst two days, before evacuation, symptomsrelated to the skin and the gastrointestinal tract were noted in a large number of Rongelap people, in a lesser number amongthe 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-