20 a few instances showed conflict between the re- Growth and DevelopmentStudies In evaluating the growth and development data on these children,serious inconsistencies in birth date information have been uncovered. Official written birth records did not exist for most of the children. The parents actually had norealistic perspective of time. No local or regional events, tragic or otherwise, were rememberedto serve as reference points. The births of some children had been registered at Majuro, but even amongthese Table 10 Skeletal Ages in 6-Year-Old Children corded date and the available circumstantial evidence. Since almost all analyses of growth data depend basically on the use of chronological ages, the painstaking task of improving thevalidity of the age data was undertaken. This amounted toa virtual reconstruction of the biological history of the childhood population ofthe island. Interviews were held with the parents, relatives, and village elders. Cross-examinations were conducted to obtain all relevant information. In spite of these efforts, a significant lack of accurate informationremained in manycases. Further attempts to check birth dates are necessary before classification of the children into age groups can be done with Subject Age at reasonable validity. exposure, Sex 2 3 5 6 65 33 M M M M F F 16 17 16 16 15 20 6 6 6 6 6 6 %2 %2 2 H2 H2 Ke 4 %2 2'K2 3 2 5 %2 3 42 7 2 955 962 980 996 814 F F* F F M ** * ** ** “* 61% 6 2 6% 6 2 6M, t t 6'%2 + 5 Me M age in 1959, yr Skeletal age* No. 54 mo Chronological 12 6 2 in 1959, yr t *Greulich-Pyle standards. **Control. tNo film. An earlier analysis of the skeletal ages of the Marshallese children had indicated possible retardation 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 chronological age group three boys and onegirl out of five boys and two girls exposed to radiation were markedlyretarded in skeletal maturation (Table 10), The birth dates of these particular children seemed firmly established. The boys showing most retarda- tion (#2,3.and 5) were 16 to 17 months old and the girl (+263) 15 monthsold at the time of expoTable 12 Tabie 11 Comparison of Stature (1958, 1959, and 1960) of Children With Retarded Osseous Development Height and Weight of 6-Year-Old Children Skeletal age peers Subject No. Height, cm Weight, lb Height, cm Weight, Ib 2 3 5 6 108.3 102.2 98.8 106.3 41.5 39.5 36.0 41.0 99.3 95.3 104.8 109.0 32.0 32.5 36.1 41.0 33 34 955 962 980 996 115.8 112.5 117.5 108.3 112.8 108.0 43.8 47.5 47.5 42.3 43.8 35.0 118.2 — — _ — — 47.4 — ~ —_ — — 65 814 98.4 111.7 33.0 43.0 ~ _ _ _ With That of Their Next Younger Sibs Stature, cm Sex Born 1958 1959 1960 Subject (#5) Sib (#85) M M~ 10/20/52 3/ 7/54 95.7 95.5 98.8 100.9 102.2 108.0 Subject (#2) Sib (#91) M~ M 10/23/52 1/ 3/55 103.0 898 108.3 97.1 115.6 104.1 Subject (#3) Sib (#83) M M 9/11/52 6/ 8/54 98.5 97.6 102.2 986 106.7 113.0 Subject (#65) Sib (#86) F F 12/ 4/52 10/17/54 930 90.6. 984 97.0 1029 103.5 Subject (#6) Sib { #84) M M 10/14/52 5/31/54 106.3 98.6 111.8 104.8 100.4 94.2