(2) indicates the effect of plowing Engehi only while modification (3) reflects the additional effect of plowing all the northern islands. Deeper plowing or turning over the soil rather than mixing it would of course result in even greater exposure rate reductions. For example mixing to a depth of two feet would reduce gamma exposure levels by an additional factor of two, while covering ‘the sources with approximately a foot of uncontaminated soil would essentially reduce the eventual integral gamma-ray doses from 137 cs and ©0¢9 to negligible values, ive.. doses everywhere similar to those calculated for case IV. Removing the first 6 inches of top soil which now usually contains over two thirds of the activity, rather than plowing, would result also in am mo about a factor of three reduction in‘exposure rates. Based on the result given in Table IV, however, extensive modifications may not be necessary. If we compare the unmodified integrated exposures with values calculated for typical U. S. sea level locations which are also given in Table IV, we see that even for Cases I, and Lp the 70 year integral dose is only slightly greater than the comparable "typical" U. S. value.