10 rads, Calculation of the dosage from radioiodines unfortunately had to be based on a single, pooled urine sample from Rongelap people collected 15 days post exposure. Harris?" at Los Alamos had reported a lowlevel of !31] in this sample and had calculated a one-daythyroid content of 11.2 pCi based on the assumption of 0.1% urinary excretion of the maximum thyroid burden on the 15th day. James calculated doses for absorption from both inhalation and ingestion. He noted that the shorter- lived isotopes of iodine delivered 2 to 3 times the estimated dose delivered by 131] alone. The importance of these shorter-lived isotopes in pro- ducing thyroid effects in the Marsigullese will be referred to in Section IV._The dose: : thyroid of a Rongelap adujt (including gamgaa}-was calculated as about’33%¥ads (220 te 450rads) and to that of a 3-year-old Rongelap childas 700 to 1400. <2 rads. (The spread ts due to uncer@kinties in esti- 20 _ mating dose from absorption of radioiodines by =*thalation versus ingestion.) With the assumption 7 that the ratio of whole-body gammadosesto thyroid doses was the same as for the Rongelap people, James’ calculations were used to estimate Thyroid wt (g) thyroid doses in the Ailingnae and Utirik groups; ’ the results were 135 rads for the Ailingnaeadults and 27rads for the Utirik adults. children’s The ‘thyroid _doses were based on theweightthe of gland at various ages(Figure 3).28 By using a 0 b L 5 , 10 I5 1. Sr 0 20 Age Figure 3. Weights of human thyroids in New York City. (From Mocuizuki ET at.?8) $400 OTT linear relationship between the thyroid size and the dose calculated by James, the doses to individual children were taken from regression lines drawnfor the three exposed populations (Figure 4); these are given in Section IV. In retrospect, the estimated average dose of 1050 radsto the thyroids of young children appearsto 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 }3!1I must be related partly to the greater dose effect of shortlived iodine isotopes (see Appendix 9C). oa . JT B. ACUTE EFFECTS YF T | T tT T j T Thyroid dose (rads) “FEBeets of Whole-Body Exposure 0 0 _-7 Utirik pop Lo 5 a a TOY 10 Age rot 15 20 Figure 4. Thyroid dose versus age for children in exposed Marshallese groups. .SmaeEarly r Symptoms. Duringthe first two days, ks evacuation, symptomsrelated to the skin “She gastrointestinal tract were noted in a 2Sattge numberof Rongelap people, in a lesser number among the groups exposed on Ailingnae and Rongerik, and in none of the Utirik group. The severity of the symptomswascorrelated with the amount of fallout and the radiation dose. Skin symptoms(itching and burning of 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 beta irra-