Table 1. Levels and decay rates of beta radioactivity of Rongelap-Ailinginae plankton, 1954-1957 Decay slope Plate No. Atoll designnation Island 8201 Rongelap 8202 Labaredj '"! " 12 W " Kabelle tt 20 it tt 6 iD It UW 't 6 20 it " Labaredj " Rongelap " Labaredj " Kabelle vo Lukuen " Kabelle 1 " Rongelap 1 iw "t tt tt u / iT tt " it Lb uO " " Ailinginae " 6 20 6 20 6 20 6 20 6 20 Ww Rongelap per inch " 2330 -_ 1. 32 i 9 2 " tt 4000 140 1 . 27 68 2.1 74 " . . 20 7-16-54 8-11-54 1-3-55 20 " tt —- -- it " 20 12-8-54 74 " " 12-18-54 74 " " 1-26-55 " 1-28-55 it n 173 173 TH " u w " it H 83 46 -- 1.08 2.7 _ 1.32 1.33 " Ht " 168 10.4 6.2 - 1.75 " 104 -55..0 - 1.72 i" 2-22-55 it " 1" 74h " ut " " 1-29-55 " 74 " " 1+30-55 " 173 173 74 n Nylon tt tt 173 157 tt 58 93 37. 95 95 .93 . hy - 1.68 - 1.72 ~ 1.56 ~ il. 55 1.8 - 1.61 11.5 ~ 1.70 5.8 u . uy ~ ~- 1.61 1 . 70 " 10~22-55 2.1 O44 = " " 10-23-55 " " 10-24-55 11-27-55 74 170 27 12. 54 1.73 - 1.76 7TH 170 au - 20 " 151 Li 25 3.9 1,35** 6.4 " 2 tt " 32 ~ 10-21-55 11-26-55 " 74 HW 168 " " t 20 Silk i or 2 20 ing to Oct. 30, 1957 5-11-54 157 it Ash Wet basis basis first count- 3-26-54 2 Rongelap from date of in uc/kg* ? 173 ? collect- first ing counting First count 9 157 1 of net inches Date of 2 " " ial Date of tt 2 Mo jiri-Enibuk 1 " 1" | Diam- Meshes Mater- eter 125 H Wl " Plankton net Number " " " Silk tt " w 12 it " " " " " " " " vf 1" 7-23-55 8-23-56 "i tT 6.9 .18 047 2.0 - 1.72 . 73a = 1.38 HAS .70 - 1.58 4.6 94 - 1.71 5.5 34 7.4 41 178 .80 2.2 19 1.53 - 1.73 - 5.3 -11 4