20 a few instances showed conflict between the re- Growth andDevelopment Studies on these children, serious inconsistencies in birth corded date and the available circumstantial evidence. written birth records did not exist for most of the basically on'the use of chronological ages, the perspective of time. No local or regional events, tragic or otherwise, were remembered to serve as reference points. The births of some children had been registered at Majuro, but even among these the childhood population of the island. Interviews Table 10 forts, a significant lack of accurate information re- In evaluatingthe growth and development data date information have been uncovered. Official children. The parents actually had no realistic Since almost all analyses of growth data depend painstaking task of improving the validity of the age data was undertaken. This amounted toa virtual reconstruction of the biological history of were held with the parents, relatives, and village elders. Cross-examinations were conducted to obtain all relevant information. In spite of these ef- mained in many cases. Further attempts to check birth dates are necessary before classification of Skeletal Ages in 6-Year-Old Children the children into age groups can be done with Subject NO. Sex Age at exposure, mo 2 3 5 6 65 33 54 955 962 980 996 814 M M M M F F M F F FE F M 16 17 16 16 15 20 12 ** ** ** ** ** Chronological agein 1959, yr Skeletal age* in 1959, yr 6 M2 6 Sa 6 Ae 6 H2 6 Az 6 Me 6 “2 6%. 6 42 6 2 6 He 64a 4%. 2% 3% 5 a 3%. 7 Mo T t t 6% 7 5 Az *Greulich-Pyle standards. **Control. {No film. reasonable validity. An earlier analysis of the skeletal ages of the Marshallese children had indicated possible re- tardation in development among the exposed group.° Since such comparisons required reference to accurate chronological ages, further detailed analyses of this type were deferred. It was noted, however, that in the 6-year chronologic4l age. group three boys and onegirl out of five boys and two girls exposed to radiation were markedly retarded in skeletal maturation (Table 10). The birth dates of these particular children seemed firmly established. The boys showing most retardation (#2,3,and5) were 16 to 17 months old and the girl (#65) 15 monthsold at the time of expoTable 12 Table 11 Comparison of Stature (1958, 1959, and 1960) of Children With Retarded Osseous Development With That of Their Next Younger Sibs Height and Weight of 6-Year-Old Children Skeletal age peers Subject No. Height, cm Weight, lb Height, cm Weight, lb 2 3 5 108.3 102.2 98.8 41.5 39.5 36.0 99.3 95.3 104.8 32.0 32.5 Sail 6 65 33 54 955 962 980 996 al4 106.3 98.4 115.8 112.5 117.5 108.3 112.8 108.0 Lil? a Stature, cm Sex Born 1958 1959 1960 Subject (=5) Sib (2285) M M 10/20/52 9/ 7/54 95.7 95.5 988 100.9 102.2 108.0 41.0 109.0 41.0 Subject (2) Sib (=91) M M 10/23/52 l/ 3/55 103.0 =89.8 108.3 97.1) 115.6 104.1 43.8 47.5 47.5 42.3 43.8 35 0 +3.0 118.2 — — — — — — 47.4 — —_ — — — _ Subject {23} Sib (83) M M 9/11/52 6/ 8/54 98.9 97.6 102.2 98.6 106.7 113.0 Subject (65) Sib (+86) F F 12/ 4/52 10/17/54 93.0 906 984 97.0 102.9 103.5 Subject (#6) Sib (84) M MI {0/14/52 5/31/54 100.4 94.2 106.3) 98.6 [11.8 104.8 33.0 — as,