for the calculation of wet-chemistry- tions. equivalent 2395.) tam concentrations. Although the average 24d an: and 241 23a 240 Pu dpm ratios Comparisons of the Bikini soil, Eneu of 1.11 + 8.1% and 0.512 + 7.9% are soil, and Bikini vegetation are different than those in the Bikini presented in Tables 11, 12, and 13, soils when compared on an atsolute respectively. basis, Only those samples the deviations associeted giving positive 241 and 239,240, with the individual determinations signals have been included. indicate that the soil and vegetation _ From Table 11 it is apparent ratios are the Same. that the Bikini soils exhibit quite PLUTONIUM-ISOTOPE RESULTS consistent 241ns Pu Yatios regardless of the profile depth. fact, In Mean isotopic atom ratios of the agreement among the mean 24054 and 241oy to 2395 have been ratios for the various profiles calculated from the individual mass is rather remarkable. Spectrometric results. Results indi- cate that the average dpm ratios of 244ni py and 24dye 239 t2 40, on These ratios from the various sample types and sampling locations are presented in the island are quite specific and are Table 14. 1.17 + 8.1% and 0.550 + 8.1%, activity ratios as determined from respectively. the mean atom ratios and half-lives Table 12, As evidenced in Also included are the listed in Table 4. there is also excellent Soil results from agreement among the Eneu soil samples. the two islands are indistinguishable. Although the total number of samples Statistically, the soil and vegetation is considerably less, there is no results are in agreement... The absolute appreciable variation with profile differences between the 240 pu depth. For Eneu Island soil samples, the 241.2395, and 2412394240, | soil and vegetation results show the difficulties associated with the dpm ratios are 1.08 + 3.0% and measurement of minor isotope in 0.512 + 3.6%, respectively. samples with low concentrations. Statisti- cally, there is no difference between Extensive experience in mass spectro-~ the 241 to Pu concentration ratios metry has shown that for low level of these two islands. samples such as vegetation, measure-— Bikini vegeta- tion ratios in Table 13 are in ment of minor isotopes wil] be biased reasonable statistical agreement as higher than indicated by the fact that the average To construe that the differences in dpm ratios exhibit lower deviations soil and vegetation are an indication than any of the individual determina- of fractionation would be erroneous. ~20- WD 50 0052 the actual concentrations.