.- C (— THYROID LESIONS IN MARSHALLESE EXPOSED TO FALLOUT (AS OF MAY, Marshall Island Group (radiation dose-gamma) Age at Exposure 1974) Estimated Thyroid dose-rads Thyroid Lestons Percent Thyroid Surgery Malignant Lesions Percent 15 5.3 (1/19) Rongelap (175 rads gamma exposure) In-utero <10 175 + ? 675 - 1440 33.3 (1/3) 89.5 (17/19) Rongelap (on Ailingne 7" "EFG° 586 T dao «378 (2/64 11-16 >16 all - Island -69 rads gamma exposure) +16 all Utirik? (14 rads gamma expvsure) <10 >10 all Rongelap unexposed <10 >10 Likiep unexposed (1970) L Dose from 131, 132, 133, 335 - 675 335 9 132 - - - - <10 - all - 135 4 0.0 (0/53) 5.8 (6/104) 3.2 (5/157) 0 4 4 1.0 (1/104) 0.6 (1/157) 1.6 (1/61) 0 3.6 (7/194) 2 0.0 (0/31) 0 3.6 (5/137) 0 4.7 (5/106) 2 3 2 0 - - - - - - I plus gamma dose. 2Rased on number of original people exposed. in group. 3 5.4 (2/37) 4.7 (3/64) . 4.5 (6/133) - 1 3 17 1 16.6 5/533 22.2 (4/18) 40, - 80 22 - all 12.5 (1/8) 8.1 (3/37) 32.8 (21/64) In parentheses number of cases/total number The thyroid is considered fully developed by age 16. . os Difference of opinion as to whether or not one lesion was malignant. was that it was benign. Majority opinion The more energetic shorter-lived isotopes of iodine contributed less to the total thyroid dose in the Utirik people due to later fallout. One might surmise also that the biological effectiveness of the thyroid dose per rad would be less in that group. Or ifteen children 10-17 years of age at exposure in this group received estimated thyroid doses between 22 and 40 rads. "tn addition to thyroid lesions, one case of acute myelogenous leukemia was discovered in September 1972 in a 19-year-old Rongelap boy who had received 175 rad gamma radiation at one year of age. He died November, 1972.