are based mostly on activity which has condensed or become connected to Pacific Island coral or sand particles and the results may not be applicable to other types of environment. Activity information for each of several isotoves in each fraction are presented in the Project 2 6b report. TABLE 3.15 ~ Per Cent of Total Activity of Shot l Size Graded Samples from How Tsland* NMD of Fraction puke 1.l 32 22 27 38 56 69 79 98 103 x * 160 171 195 > 225 TOTAL Ht 3-10 Weight (gm) Total Activity Per Cent of Fracof tion in Total Weight Arbitrary sett 22901 0.975 0.112 0.923 0.597 1,031 0.400 0.522 0.408 0.646 0.691 0.757 0.983 19 e662 30.608 9447 3419 0.366 3.02 1.95 3 36 1.71 1.31 1.33 211 2026 2047 3.21 64020 100 Per Cent of Total Activity in Fraction Units at D# 7 Days {| 731 2029 0.323 2045 1.96 3022 1.16 1.30 0.950 1.445 1.56 1.58 1.98 13.5 41.0 17.8 § 59 0.788 598 4078 7.86 283 3e17? 2032 3.54 3.81 3-86 4.83 32.9 100 Project 2.4b results 12 Project 2.4b reports the fractions as the mean volume diameter of the particles, not as the number mean diameter Both radioactive and non-radioactive particles in the fraction PARTICLE CHARACTERISTICS The average density of all particles was about 2.6 g/cc. The index of refraction of all Shot 1 particles was about 1.544. The fallout material from Shots 1, 2, and 3, which remained after the removal of samples for particle-siza analysis, were mixed and sieved through 420, 210, 149, 105, 74 and 44 micron sieves.s (Not enough fallout was collected from Shots 4 and 6 to make these analyses. Rach fraction from each shot was separated into two groupse 90