: ee ECL ” . a, FASE G Kove Reesyp *e In considering the reduction in exposure that may be achievable throught reroval of contaminated soil, the Task Group has taken the position that thes predicted exposures are approximations only. The effectiveness of such actio to reduce internal exposures that come through the food chain must be con~~ firmed through analysis of test plantings. The Task Group does not favor,soil, cs < renoval as a dependable or feasible exposure reduction action for the dietary aa he pathway- However, such action is reviewed in the Task Group Report in order - ‘to present a comolete picture of the various possiblities considered. Data from these profiles are presented in Figs. B.8.2.a-n of Appendix II of NVO-140. Inspection of these profiles ae indicates that, on the average, about 40 co of soil would have to be removed to reduce the activity in the top 2 cm layer by a factor of 10. In addition, - | 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 depthsgreater than 100 em./ =” BEST AVAILABLE COPY— — oe depth, therefore, require an est imate of the ratio of the averag e concentration of the nuclides of concern in the 0-15 cn depth of the newly exposed surface to that for the surface which is present now. - ov a Removal of successive 15 cm layers of sofl in the subsistence agricultural areas, howeve r, may reduce the bone dose by significant amounts. Removal of the top 15 cm layer, for example, may reduce the 30-year-bone dose from 57 Rem to 19 Rem, while removal of an additional 15 cm may bring the dose down to 10.7 Rem. ' \2"