724 genetically GROWTH AND RADIATION inherited characteristics of blood components and_urine. The routine anthropometric measurements consisted of stature, body weight, sitting height, head circumference, head width, head length, chest circumference, calf circumference, bisacromial diameter, and bicristal diameter. Weight was deter- mined on a Fairbanks scale, beam balance. Stature was measured on a fixed wall scale using a right-angle square. Circumferences were determined bya flexible steel tape and diameters by Swan Tool spreadingcalipers. Techniques conformed basically to those used internationally in physical anthropo- metry.*® The growth data used in this anal- groups were plotted in terms of group me- dians. Descriptive differences reported as between groups were differences between medians. Significance of differences between groups, unless otherwise specified, was determined by the Kruskal-Wallis oneway analysis of variance.”° Height and weight data on unexposed children born before the fallout showed the expected pattern of pubertal growth spurt occurring earlier in girls than in boys and the eventual superiority in size of boys at maturity. Among the exposed children, there was a distinct tendency for boys exposed at ages 1 through 5 to be shorter than unexposed boys of the sameage(Fig. ysis were obtained by a single observer 1). Although the differences werestatistic(W.W.S.) except in 1960 when only the ally significant at the 5% confidence level heights and weights were determined on exposed children (by R.A.C.). Evaluation of sexual maturation was done during the physical examination using standards described by Greulich et al.'* and STATURAL GROWTH '958-1963 rT Tok seous development was carried out by a single evaiuator (W. W.S.) using the technique of Greulich and Pyle.” culations of any meaningful measure of variability), all data analysis was done by non-parametric statistical methods. All measures of central tendency were medians, and all graphic presentations comparing @ tT bt tt fo u—« EXPOSED @~-o CONTROL @® BIRTH YEAR GROUP ( AGE AT EXPOSURE) —-_ &> —— jaa 7 in 7 get 130-- #, Go the fallout but not exposed to radiation; (c) those born to exposed parents subsequent to the fallout; and (d) those born to unexposed parents subsequent to the fallout. Because some of the distributions encountered in these data did not approximate normality or even symmetry of distribution, and because many of the groups were too small to justify making assumptions about the parameters of the populations from which the samples were drawn (and in many instances too small to permit cal- } 160 HEIGHT {em) The pediatric study population was di- vided into four groups: (a) those exposed to radiation, including 4 children in utero at the time of exposure; (b) those born before ft Bors Reynolds and Wines.’7:!® Assessment of os- RESULTS iT 110 + 100 905 4 6 Lttteprertt 8 10 AGE (YEARS) 12 4 t 16 Fic. 1. Statural growth of boys, 1958 through 1963. Longitudinal growth curves showing median statures of groups of boys exposed at various ages, e.g., in utero (u) 3 boys; 12 to 24 months (1) 5 boys; 3 through 5 years (3-5) 4 boys; 6 through 8 years (6-8) 3 boys; and 12 through 13 years (12-13) 2 boys; indicate definite and continuing retardation in statural growth of boys exposed at ages 5 years or younger and particularly 12 to 24 months of age. “OC Oe