-17- abnormalities have been noted, all of these occurring in the more heavily exposed group except one in an adult in the Ailingnae group (Conard, Rall and Sutow; Conard et al.,1967; Robbins, Rall and Conard). Only 3 such cases have been detected in adults, the remaining 16 cases having occurred in children exposed at less than 10 years of age. Table 3 shows the high incidence (84%) in this younger group and lack of euch findings in the lesser and unexposed children. A low incidence was noted in the adults. Table 3 Thyroid Nodules’ (Including Hypothyroidism) In Marshallese Populations (R=Rongelap; A=Ailingnae; UT=Utirik; .C=Unexposed) Group Age At Exposure No. in Group Gamma Dose (rads) R A UT C <10 <10 <10 <10 19 6 40 61 175 69 14 0 R A UT C >10 >10 >10 >10 36 8 59 133 175 69 14 0 Estimated Thyroid Dose (I*, rads) 700-1400 275-550 55-110 0 160 35 15 0 4s Thyroid Nodules ' . 84 .2 0.0 0.0 0.0 5.5 12.5 3.4 2.3 *In estimating the thyroid doses to the Ailingnae and Utirik exposed group, it was assumed that such doses were proportional to the thyroid doses of the Rongelag exposed group, based on relative whole body gamma dose received. Thyroid surgery was performed on 9 children and 2 adults.** All nodules were found to be benign in the children and one adult. The other adult, a 41 year old woman in the higher exposure group had a thyroid cancer. In addition to “Surgery on the first 3 cases was performed by Captain C.A. Broadeus(MC)USN, U.S. Naval Hospital, Guam, and on the other 8 by Dr. Bentley P. Colcock, Lahey Clinic, Boston, Massacnusetts. sogu3i4