Table III. Radioisotopes Present in Plankton Collected soon after Fallout Per cent of Isotope Half life total radioactivity Bomb debris Np239 2.3 days 69 u237 6.8 days 3 Fission products Mo29- 729m 66 hours 12 Te 132_ 1132 77 hours 8 Rul03-Rp103 40 days Ru105- Rpl05 36 hours”) Ry 106- ppl 06 3 1 year Ba! 40-1,,140 12.8 days 2 Cel4#i_p,i41 33 days 2 Zr95 -Np95 65 days 1 285 days <] Cel44.pyi44 100+ 1) Data from Lowman, (1960; average value for six samples collected less than 48 hours post shot; fallout from one detonation. Rehoboth survey,( 1959 2} Half life of daughter