‘80 EFFECTS OF IONIZING RADIATION 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 45 days the decay curve is essentially that of Sr®, the most abundant of the longer-lived elements deposited. Theresidual total beta activity found in the two larger fish at 4 months post detonation averaged 2.5 pc (Table 5.10). There was, at the same time, about twice as much gammaactivity. The tish were collected 56 days post detonation, and the drop in activity between that time Table 5.10.—Beta and Gamma Activity of Fish From Rongelap Three Months Post Detonation Fis #1 (802 Gm) | | i | Groas Actrviry, ac Ba, Sr | RaDIOCHEMICAL ANALYSIS (PERAND RARE CENT} iN Ba, Se and Re ora FRACTION ! Bata GQaMMa (Pancest) | Head._...--2.-.--2--.---- | Scales + Fins + Tail... ..-_-- ‘ 0. 568 0. 500 1. 26 0. 58 9.9 95 Gills. -- 2.2.2.2 222222 eee Remainder of Body._...-_.. 0. 160 0. 596 0. 43 1. 78 Total. ._...--....-2-- 2. 724 6. 41 ~ Sree Eagtu | Viscera....-.-.--.---- ee | 0900 236 | = 420 / 7.8 8.3 38. 3 «(174 | 0. 101 0. 23 1. 620 214 Scales + Fins+ Tail. ...__._- | 0. 067 Gilla. 22.22 -- ele 0. 043 0. 09 2.179 3. 58 Viscera_.......-.--2. 22-22. | Skeleton._.....--.--------. Muscle._......-..---.----- 0. 197 0. 151 Total. ..--22-- 2-228. | | _ | | Tota, Beta ACTrVITY—6.4X 108 p/m RADIOCHEMICAL ANALYSIS PERCENT ov TOTAL ACTIVITY Zr, eee 24 Other. ....-2.2.2-2.--2--------- 114 Samples collected two months post detonation. 0. 045 0. 058 79. 4 43. 6 980 324 0.7 0.7 33. 4 0, 017 0. 084 0. 205 0. 023 0. O11 0. 301 0. 461 0. 030 0. 038 CLam #1 Sree. Bal@__ 2 eee Rare Earths....--._.-.-------- 6.7 11.2 08 0.115 0. 35 0. 53 Rui ee. 52. 1 72.7 Gross ACTIVITY, uc Beta GaMMa 0. 23 RaDIOELEMENT 9.6 9.9 Fisk #3 (168 Gu) GRoss ACTIVITY, uc Bata CAMMA Head. __-.--..----..----- 14 13. 9 45, 2 Fisu #2 (SOT GM) - Rare Bassé 0. 070 0. O74