THYROID LESIONS IN MARSHALLESE EXPOSED TO FALLOUT (AS OF MAY, 1974) Marshall Island Group (radiation dose-gamma) Age at Exposure Rongelap (175 rads gamma expesure) [n-utero <10 Rongelap (on Ailingne Island -69 rads gamma In ULERO 16 exposure) Utirik? (14 rads gamma 11~16 >16 all - all Estimated Thyroid dose-rads i75 + ? 675 - 1440 335 - 675 335 9 488 - 480 132 Thyroid Lesions Percent Thyroid Surgery 33.3 (1/3) 89.5 (17/19) 15 12.5 (1/8) 8.1 (3/37) 32.8 (21/64) 33:3 ora 16.6 51983 - 1 3 17 Malignant Lesions Percent 5.3 (1/19) 5.4 (2/37) 4.7 (3/64) 22.2 (4/18) 1 2 3 . - <10 40, 80 0.0 (0/53) O - all - 3.2 (5/157) 4 0.6 (1/157) Rongelap unexposed <10 - Likiep unexposed (1970) <10 exposure) >10 >10 all ” all lnose from L3i, 132, 133, 155 22 - 4 1.6 (1/61) 0 0.0 (0/31) 0 4.5 (6/133) 3.6 (7/194) - 4.7 (5/106) 3.6 (5/137) 2 2 0 0 1.0 (1/104) - - - - I plus gamma dose. *Based on number of original people exposed. in group. 3 5.8 (6/104) In parentheses number of cases/total number The thyroid is considered fully developed by age 16. 4p 4 fference of opinion as was that it was benign. to whether or not one lesion was malignant. 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. Sri fteen 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.