GROWTH AND RADIATION a™ one ny we ay A cence eke at ¥ at me eae at “yMeleta Suthers esskaabenshs yt gm aN greys Saag at eet at A Lo 728 n Se b ety noe Ria tage a So, Sete ee Fic. 8, Skeletal age roentgenograms of left wrists and hands. (A) Subject No. 3 shows marked retarda- tion in skeletal maturation at chronological age of 10 years 6 months. (B) Subject No. 83, younger exposed Japanese populace.*? Reynolds™ examined the growth data obtained from 1951 through 1953 on the Hiroshima children and reported a trend in the direction of inferior physical status in the exposed as compared to the control children. He further interpreted the data as demonstrating a tendency among children exposed closer to the hypocenter to be physically smaller than those exposed farther away. Similarly, inferior growth status was more marked in those children with histories of more severe radiation symptoms. Recently, Nehemias*® utilized multivariate techniques with twelve anthropometric variables to analyze the 1951-1953 ABCC growth data. He concluded that there were trends “in the direction of decreasing size with increasing degree of radiation expo- sure.” It was noted that the differences in size were physically small, not detectable for the most part in the age-sex-specific tests. Correlation analyses indicated that “the effect tended\to be most marked at the older and younger age groups,” i.e., in children who were “either in infancy at the time of the bomborin the 12- and 13- year-age range”. Even in the large-scale ABCC program, the problems related to the selection of a control population for purposes of comparison have beendifficult to solve.**-?5 Al- though quantitative differences in growth between exposed and unexposed children can be shown to exist statistically, the causal relationship of the biological effect of radiation to the noted difference remains to be proved.?* Factors such as physical and psychic trauma added to nutritional deficiencies could have influenced growth and development in the Japanese children. These factors that complicated the interpretation of growth data in the ABCC program would seem to be of minimal im- portance in the Marshall Island study. Significant sociceconomic differences do al brother of No. 3, has vomreeRS KP age of 8 years 8 months,