Table 1. Percent of persons in Marshallese populations having thyroid nodules (1979). Age <18 in 1954* No, Z with nodules 4.8 2.4 44 79 15.9 11.4 4.5 1.3 0.7 0.2 115 11.3 0.9 103 102 3.9 1.0 1.0 0.0 59 90 6.8 4.4 0.0 0.0 1193 / 1.2 292 8.2 0.7 Group No. 2 with nodules 42 85 52.4 9.4 553 435 2 with carcinoma Age >18 in 1954 & with carcinoma Exposed in 1954 Rongelap ucirik kk Comparison populations Rongelap Utirik Wot je Likiep ALL 1.4 0.2 0.25 38 7.9 2.6 (1 case) *The comparison populations include children not yet born in 1954. prevalence not subtracted from exposed estimates. **Includes 19 people exposed on Ailingnae. Unexposed from natural radiation might have been subtracted from the above estimates. Exposure to natural radiation during the years the people were away from their home island was not added to the above doses since comparisons are to be made with unexposed population statistics, in which such exposure is inherent. Table 3 shows the expected percentage of persons with thyroid nodules and cancer dee to exposure to residual radiation on Rongelap and Utirik. Esti- mates are calculated for the highest exposure doses assuming continuous habitation on the islands (half-time habitation for children). The table shows that the percentage of people with thyroid nodules and cancer would not be detectable in a population this size and would be far below the spontaneous incidence. The data presented are probably overestimates in view of the factors discussed above. - 105 -