Table 2. Percent of unexposed Marshallese (born before 1954) with thyroid nodules. Established (1958) Age group (i954) <10 10-18 >18 All group (Roneelap) tetal a 2 No. Nods. Carcinoma** 58 29 98 86 3.4 6.9 9.2 =««6..9 1.7 a 1.0 1.1 Added groups* total Combined groups total 2 * No. Nods. Carcinoma** % z No. Nods. Carcinoma** 1712.3 50 «8.0 194 7.2 415 5.3 0.6 0 0.5 0.5 229 79 292 600 2.6 7.6 7.9 5.8 0.9 0 0.7 0.7 *Added unexposed people of Rongelap, Utirik, Wotje, and Likiep. See Table 1, Appendix I, for island breakdown. **The carcinomas gay be underestimated since all unoperated nodules were considered benign for these calculations. Occult papillary carcinomas not inc luded under carcinoma. Table 5. Group Ronge lap Observed/expected thyroid nodules.* Exposure Age <18 No. 22/1.6 2/0.4 85 8/3.3 2/0.8 >18 7 " >18 79 <18 Carc inoma** 42 " Utirik Total nodules 7/3.5 9/5.7 2/0.3 1/0.6 *Based on unexposed Marshallese prevalence: <18, total nodules 3.92%, carcinoma 1.0%; >18, total nodules 7.9%, carcinoma 0.72%. *eDoes not include occult papillary carcinomas. - 60 -