i oO ae o a Mg pe o Laney Le] iy Us rt Hs ° a my rt Lv] Leh m Age differences in the acute and lete min ing exposure to radiation fallcut have been documented dn the Rongelcp popu dation. Tho ceverity and frequcnacy cf several abnormal findings appearad to be correlated inversely with chronolesical age, that is, wore cevere da the youager subjects. The data, however, da not indieate whether the dir- ferences ere du2 to increased biolosical sensitivity of the tissues of young children or to dose differences. Observations during the annual surveys indicate that the children wear less clo thine end thet they spend considerably more time in the open, ovay from houses and overhead protection, then do adults. on the open ground with great frequency. Young children play Thus, during the two drys before evacuation, they would have had greater and more prolonged contact with fallout watertal and would have been clos adults. to the surface deposits than would Moreover, the physical siszes of the children were such thet they greater dose at midline than adults receiving tha sane air dose. These factors no doubt contributed to the skin lectons and greate: cepression of blood elements in children compared to adults. The greater incidence of thyroid abnormslities in the children vas probably only to inerecsed radiation dese to the children's glands, but also to the ror wa greater proliferative activity of the growing gland with lack of replacement \ of injured cell : Ciinical and laboratory data indicatad that total destruction of the 3 That pevtial destructioa cf tha mn a) G rc x o MH 0 glends mey heave resulted in ot [He thyroid gland occurred in tvo youngsters. lowered thyroxine velues, reduscd upteke of radtododinge cud the inability