32 Nevissi and Schell (1974) have reported on the distribution of 23942405, a Ar, 258,, U, 297,. oe : Bi and several fission products in surface and deep water ecllections at Pikini tcken concurrently with the sediment samrles reported herein. The water collections were partitioned in situ in soluble-colloidal (< .3um) and particulate (> .3um) fractions. Volumes of up to 4000 liters of water were sampled at each sediment collection station. Some of these data are Shown in relation to the measured sediment concentrations and discussed in jeter sections of this report. Noshkin et al. (1974a) calculated the past concentrations of radionuclides in Bikini laqoon waters by assuming that the concentrations of radionuclides measured in dated coral sections were proportional to the marine concertrations present at the time of coral growth. They conclude that the eluecus concentrations of 60 “Co, 207,. Bi, 241 Am, 155 Eu, and plutonium isotopes at ‘rin? Atoll decreased between two and three orders of magnitude between 1954 ere VG©. The aqueous concentrations of radionuclides have not, according to ‘t+ coral concentration data, decreased since 1966. In these same coral ‘S¢, Mass spectrometric measurements of the concentration of plutonium Cutt Ame eM te peepee, 285 Q STLCT AS Pu, 23 Pu, 24050 and 24T an were made. . On the basis of the Pu “tib* ratios measured in the different coral sections, they warn that the *rironcental behavior of isotopes may not be predicta ble by measurements of * Vetere. a7 Bee 7}. a The concentrations of plutonium isotopes in the 1971-72 growth of the coral, as reported by Noshkin et al. (op. cit.) are shown in These authors also report evidence (contrary to the findings of "ee, 1565) that indicate 2105), was produced by (a) nuclear tests.