as the depth increases the slope of the activity-vs-depth curve tends to decrease,i.e., the activity levels do not go to zero, even at depths greater than 100 cm. Table 5 shows pertinent data for arn In an attempt to quantify this distribution and obtain an approximation of the ‘average profile’ ror calcuiational purpeses, 9055 and 13705 daca for each of t fourteen profile samples have been reproduced in Tables 6 and 7. values for 90. for each sampling depth are plotted in Fig. 4. The average It is apparent that from the surface to about 30 cm the 905, specific activity is decreasing with a "soil half thickness" of 8.4 cm, while in the 30 to 85 cm depth range the half thickness increases to 22 cm. The levels go not get as low as those found on the southern islands (0.5 pCi/gm) at any depth down to 180 cm. Those profile samples which lia in or closest to the subsistence agriculture areas of Figure 2 have been averaged and plotted in Fig. 5. In this set, the half thickness is only 4 cm from the surface to 10 cm, but increases to 25.5 cm in the 10 to 85 cm depth range. plotted in Figs. 6 and 7. Similar treatment of the 13766 data is In Fig. 6, where all samples are averaged, the half thickness is 4.5 cm down to about 10 cm, and 12 cm from 10 to 85 cm. Levels equal to those found on the southern islands (0.2 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. For both 90. and 1370, it is apparent that the profile averaged over all samples is more conservative than is the profile for subsistence agricultural areas for estimating the Setects 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. 009