REPAIR ASSOCIATED WITH THE EROSIVE EFFECTS OF FALLOUT DAMAGEIN INDIVIDUALS AND POPULATION GROUPS By Paci 8. Hansaaw 7. §. Atomic Energy Commission, Washington, D.C. This symposiumis devoted to damage caused in living systems by radiation from fallout. Yesterday, attention was given to the physical fitness in population groups. The comments I shall make will be more in terms of interpreta- This action is clarified, however, by considering have been used frequently during the past certain features of both acute and protracted irradiation exposures. The ideas I have to present deal with the problems of recovery associated with three —— ness; (2) those connected in a way with life aspects of problems involved. Today, we are turning to the biologieal aspects~ particularly repatr. Because fallout is pervasive and offective through time, its action is more subtle. | types of erosive effects caused by radiation: (1) Those that occur following irradiation sick- shortening; and (3) those involved with reduced tion than in mathematical treatments such as several months. Figure 1 gives orientation with respect to phases of the injury response in human beings following acute irradiation exposure —phases ay ACUTE EXPOSURE BLOOD AND GENERATIVE TISSYE CHANGES wy R é& ween | ic’2 %, OEATH DEATH I Hq ACUTE PHASE 6 TO 12 WEEKS INTERMEDIATE PHASE MONTHS OR YEARS int TERMINAL PHASE nner DAYS OR WEEKS Fiauns 1.—- Pattern of trradiation injury. 8T