averaged, the half thickness is 4.5 cm down to about 10 em, and 12 cm from 10 to 85 cm. Levels equal to those found on the southern islands (10.2 pCi/gm) are found at depths below about 100 cm. In Fig. 7, the subsistence agriculture case gives a half thickness of 2.7 cm down to 10 cm, and 17.8 cm from 10 to 85 cm. 0 For both 9 Sr and 137 Cs it is apparent that the profile averaged over all samples is more conservative than is the profile for subsistence agricultural areas for estimating the effects of soil removal; therefore, the Task Group has used Figs. 4 and 6 for estimating dose reductions that might occur due to removal of soil. In making these dose reduction approximations, one must keep two things in mind; first, that the NVO-140 dose estimates for terrestrial foods grown on an island such as JANET are based on correlations between certain indicator plants ond average ceil senccntrations in the O-15 cu samples (Tig. 3) since foods such as pandanus and breadfruit were not found on JANET and, second, that these concentrations are averaged over the 0-15 cm depth of Figs. 4 and 6. Estimates of dose reductions to be expected due to removal of soil to a given depth, therefore, require an estimate of the ratio of the average concentration of the nuclides of concern in the 0-15 cm depth of the newly exposed surface to that for the surface which is present now. This approach does not consider the radioactivity in the soils deeper than 15 cm which may be important, particularly for plants with roots that’ penetrate deeply into the soil. Table 8 presents these average concentrations and ratios for 90 ~~Sr and 1376, for each 15 cm increment from the present surface down to 105 cm as derived from Figs. 4 and 6. These estimates indicate, for example, that removal of 15 cm of soil may reduce the terrestrial food dose due to 9965 by a factor of 3.3 and that ~10-