43 Table 25 Thyroid Lesions in Marshallese, December 1974 Group Rongelap exposed (175 rads) Ailingnae exposed (69 rads) Age at exposure Est. thyroid dose,* rads % Subjects® with thyroid lesions No. subjects with surgery “ Subjects® with malignant lesions <10 10-18¢ >18 All 810-1150 335-810 335 556* 89.5 (17/19) 16.6 (2/12) 9.1 (3/33)4 34.4 (22/64) 15 1 3 19 5.3 (1/19) <10 10-18 >18 All 275-450 190 135 2178 33.3 0.0 36.3 33.3 175+? 33.3 (1/3) In utero exposed Utirik exposed (14 rads) 69 +? l 0.0 (0/1) tt) 60-958 0.0 (0/58) 0 >18 27 6.4 (3/78) 3 <10 10-18 1.6 (1/61) 7.7 (E/13) 0 l All 4.6 (9/194) 3 10-18 27-60 508 >18 Likiep unexposed if 0 3 4 <10 All Rongelap unexposed (2/6) (0/1) (4/11) (6/18) <10 >10 All 4.8 (1/21) 3.8 (6/157) 5.8 (7/120) 0.0 (0/31) 4.7 (5/106) 3.6 (5/137) 6.1 (2/33) 4.7 (3/64) l 4.8 (1/22) 4 0.6 (1/157) 2 0 0 0 *Dose from '51], 152], 133], and 4551 plus gamma; mean dose extrapolated from calculations?6 for adults and 3-year-olds (see Section IT). > Based on number of people exposed, excluding those in utero (number of cases/total number in group). °The thyroid is considered to be fully developed by aboutage 18. 4Qne additional case of adenoma, found at autopsy, not included here. * Weighted mean dose. ‘ Pathologists differed as to whether this lesion was malignant; it was scored as benign. ® The more energetic, shorter-lived isotopes of iodine contributed less to the total thyroid dose in the Utirik people because the fallout occurred later there. It might be surmised also that the biologicaleffectiveness of the thyroid dose per rad would be less in the Utirik group. roid surgery has been carried out on 24 of the exposed Rongelap people with removalof varying amounts of thyroid tissue depending on the extent of the lesions (20 were subtotal and 4 total thyroidectomies with parathyroidectomy inadvertently in one of the latter who was thought to have cancer at the time of surgery). Of these cases, 3 were found to have carcinomaof the thyroid and 21 to have benign lesions of the thyroid. woman (age 6 at exposure). A fourth case of cancer was found, |4 years after exposure, in a 36-year-old Utirik woman whohadreceived considerably less exposure.?3 Three of 196 unexposed Rongelap people have had surgery with removal of benign ade- nomas. All three were women. Hospital summaries of cases admitted at BNL are presented in Appendix 10. 1. Gross Appearance curred in a 40-year-old woman (29 at the time of exposure) in the heavily exposed group. Theinterval between exposure and diagnosis was 11 years.20.23 The second and third cases in this group Since the discovery of the first thyroid lesion 9 years after radiation exposure,clinicians particularly interestedin the thyroid have participated in the annual examinations. As a result, any slight irregularities discovered by palpation drew special woman aw at exposure) andin a 22-year-old picion led to the detection and removalof nodules The first case of carcinomaof the thyroid oc- occurred 15 years after exposure, in a 36-year-old attention. This high degree of scrutiny and sus-