SQ EFFECTS OF IONIZING RADIATION Theresidual total beta activity found in the of the 24 day value. These data indicate that most of the activity is associated with shortlived isotopes. The initial drop in activity is very rapid, and after +5 days the decay curve is essentially that of Sr, the most abundant of the longer-lived elements deposited. two larger fish at 4 months post detonation av- eraged 2.5 we (Table 5.10). There was, at the sametime, about twice as much gammaactivity. The fish were collected 56 days post detonation, and the dropinactivity between that time Table 5.10.—Beta and GammaActivity of Fish From Rongelap Three Months Post Detonation FisH #1 (802 GM) Ba, Sr AND RARE EARTH TOTAL ACTIVITY (PERCENT) Gross ACTIVITY, ne BETA Head___..-.-----...------ Scales+ Fins+ Tail_.______Viseera______ wee eee eee eee Gills___.__._._-..--____--Remainder of Body______.-Total____________-_- GAMMA 0. 568 0. 0. 0. 0. 1. 26 500 900 160 596 0. 2. 0. 1. 2, 724 RADIOCHEMICAL ANALYSIS (PERCENT) («N Ba, Sr and Re FRACTION 9.9 58 36 43 78 Sréé 38. 3 9.5 48. 0 7.8 8. 3 Total_.__-__________- 52. 1 9.9 0. 6 6.7 11. 2 72.7 98. 0 79. 4 43. 6 6. 41 FisH #3 (168 GM) GRoss ACTIVITY, uC BETA GAMMA 0. 0. 1. 0. 0, 0. 9. 6 17. 4 14 13. 9 45. 2 Fisu #2 (507 Gu) Head__..______-___----_Scales+ Fins+ Tail________Viseera_____.._---2- ee Gillg_._._-_-_-._---------- Le Skeleton_...._-_____-_--_ Lee Musele__._-..--------_-____- RARE EaRTH Bale 101 067 620 043 197 151 2.179 0. 0. 2. 0. 0. 0. Gross ACTIVITY, ut BETA GaMMA 23 23 14 09 35 53 0. 045 0. 058 0.115 0. 023 0. 030 0. 088 0. 0. 0. 0. 0. 0. 3. 58 0. 301 0. 461 CLAM #1 TotaL BETA ACTIVITY—6.4%18 D/M RaADIOCHEMICAL ANALYSIS RADIOELEMENT Zrs__ ee Ru, 1060 Other__-_-__-.-.----__-_- ee eee Bre ee Bale. oe Rare Earths_.__.....--2---- 2 Samples collected two months post detonation. PERCENT oF TOTAL ACTIVITY 21. 4 32. 4 11. 4 0.7 0..7 33. 4 017 084 205 011 070 O74