THYROID LESIONS IN MARSHALLESE EXPOSED TO FALLOUT (AS OF MAY, 1974) Marshall Island Group (radiation dose-gamma) Rongelap (175 rads gamma exposure) , Rongelap (on Ailingne Island -69 rads gamma exposure) Uticik” (14 rads gamma €xposure) Age at Exposure In-utero <10 11-16 >16 all - In “ET5° 16 all Estimated Thyroid dose-rads Percent Thyroid Lesions 175 + ? 675 - 1440 335 - 675 335 9 300 > 480 89.5 12.5 8.1 32.8 (17/19) (1/8) (3/37) (21/64) 16.6 (2/12 22.2 (4/18) 40,- 80 0.0 (0/53) all - 3.2 (5/157) >10 <10 Likiep unexposed (1970) <10 >10 all ” all 131, i32, 133, 135 22 - - - Percent . 5.3 (1/19) 5.4 (2/37) 4.7 (3/64) 1 - 0 - 4 0.6 (1/157) 2 3 4 1.6 (1/61) 0 0.0 (0/31) 0 3.6 (5/137) 0 4.7 (5/106) - 15 l 3 17 §.8 (6/104) 4.5 (6/133) 3.6 (7/194) - Lesions Surgery 337% (27643 132 - Malignant Thyroid 33.3 (1/3) <10 Rongelap unexposed In ose from + 2 2 0 - 1.0 (1/104) ~ - - - - I plus gamma dose. 2nased on number of original people exposed. in group. In parentheses number of cases/total number the thyroid is considered fully developed by age 16. 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. Srifteen children 10-17 years of age at exposure in this group received estimated thyroid doses between 22 and 40 rads. In 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.