24 SKELETAL AGE {MONTHS} 225+ SKELETAL AGE ASSESSMENTS : BOYS 1957-1965 oO ; 225 4 . SKELETAL AGE ASSESSMENTS : GIRLS 1957 - 1965 | ° 4 _ : ‘© 4 17 5-- 478 4 “— ~ 8 sob ~ Lo | 4 Ww 1x i be SOL _ = 2 | i25¢ 100 200-- 1 200+ : — 2 125+ at io 4 | w (OOF MALES EXPOSED s—-——* | MALES UNEXPOSED o-~——o 75h sok “ 25 ” l 25 a ao 4+ @ 4 j 4 | | 7 L 50 ! 75 _! 106 | 125 | 180 L 175 | 200 \ «6225 0—=—_250 Figure 18. 4 w : a“ CHRONCLOGICAL AGE (MONTHS?) perig T 250r T T 250 T5e 4 sok 25k a FEMALES EXPOSED *-——* a FEMALES UNEXPOSED o———o “ L 25 = 4 I 50 L 7S 1 (00 . 125 I 150 l 17) I 2000 fo 225 250 CHRONOLOGICAL AGE (MONTHS) ~ THYROID FINDINGS During the past 3 years, the development of thyroid abnormalities in a significant numberof the peopie exposed on Rongelap, and in one from Figure 19. exposed on Rongelap: 150 rads (from direct mea- surement of urinary ‘*'I),?* 100 rads (by indirect measurements on pigs removed from Rongelap plus Marshallese urinary excretion data),** and 160 rads (based on recent recalculationsof early the Ailingnae group, has resulted in extensive thyroid studies and surgical intervention in some data’’ - see Appendix 2). The last recalculations were based on analysis of pooled urine samples cases of nodules of the thyroid gland have been after the detonation; an estimate of the one-day cases. The examination and therapyofthe first 6 described.'°:*?-** Since then, the numberofcases of nodules and hypothyroidism has increased to 18, and the newcases are described below. The Radiation Dose to the Thyroid Glonds mainly from adult Rongelap people taken 15 days thyroid contentof '*"I was 11.2 wCi (5.6 to 22.4 pCi), assuming that 0.1% (0.005 to 0.2%) of the maximum thyroid burden (not corrected for phys- ical decay) was excreted in the urine on the 15th day. The dose of 160 rads to the adult thyroid was The dose to the thyroid gland from1Fadioactive "-> calculated from oral intake and inhalation of the iodine is determined by its uptake by the gland, its various iodine isotopes, considering their fission half-life in the gland,the size of the land;and the --- yield, the average energy deposited in the thyroid relative proportion ofthe several radivisotopes:of gland perdisintegration, and the time of absorpiodine involved. Therelative distribution of radiotion. The dose to the thyroid glands of children iodinesin fallout depends on the type of explosion but in general is well kffewn. In addition to '*'J, the isotopes '*°I, '*I, and to a less extent '**I con- <4 years old was then calculated by means of these factors with consideration of pulmonary function andthe thyroid size of a child that age.” tributed significantly to the thyroid dose. The only direct data available on the Rongelappeople are The mainsource of iodine ingestion was considered to be water, and since it was being rationed taken 15 days and longerafter the fallout. Three separate estimates have been made of the dose from radioiodinesto the thyroid glands of adults children drank the same amountof wateras adults and therefore had the same thyroid burden of radioiodines. The small size of the childhood thy- radiochemical analyses of pooled urine samples at the timeofthe fallout, it was assumed thatthe