? yates 86 LATE EFFECTS OF RADIOACTIVE’ 10 1INES induced opacities of the lens noted in these people as have becn seen in cyclotron work- ers and the Japanese people exposed to the bombs in Hiroshima and Nagasaki. However, the Marshallese people were not ex- posect to any neutron irradiation, the rela- tive biological effectiveness of neutron radiation being much higher for cataract formation. One of the most important findings resulted from growth and development studies of the children. These studies have been carried out under the direction of Dr. W. W. Sutow of the M. D. Anderson Hospital. Extensive anthropometric meas- urements and skeletal maturation studies, using X rays of the hand and wrist for bone age, have been carried out over the years since exposure (11). It appears that there has been retardation of growth in some children, particularly boys exposed at less than 5 years of age. The growth retardation was most marked in two boys exposed 15 See My to 18 months of age. Figure 8 shows these oS PEER Ce RSiSa eee two retarded boys. Figure 9 shows the lag on ren bri: Ficure 8. Two 12-year-old boys showing greatest growth retardation. No obvious mental retardation in skeletal age in boys exposed at less than was noted. pete : wiere 5 years of age compared with the unexposed boys. In the females the lag was less marked. ” Rongelap people at 10 year postexposure. I will have more to say about growth reDr. Herman Lisco and his group in Boston tardation shortly. (who are carrying out the chromosome We obtained successful peripheral blood analysis for us) tell me that alow prevalence cultures for chromosome studies on the of chromosomal aberrationsstill persists. EMA MALES ~tO =x _ iw -10 . t , . “, << ae a eee EXPOSED Pa CONTROL ~~ -30 Y ~. care eae mo ra ae 0-20 “ Ore 378 AGE 6-8 U 0-2 AT EXPOSURE (YRS) 3-5 6-8 Ticure 9. Comparison of skeletal age (SA) and chronological age (CA), 1961 and 1962 (pooled datay. PRIVACYACTMATERIALREMOVED y TEellFerner <<