aay ies busOs (continued) assumption is made that all cf the strontium 90 which falls on the ground is available. One knows that soils have rather pronounced exchange characteristics..j.can one gues#e..so that I would take it that this is a rather pessimistic assumption, and I was curious as to how pessimiatic it is. Have axperiments been done in putting strontium 90 inte ordinary soil and then finding out what is avatlabie? . LYBSYs LARSEN s Thatta whet you're doing, im't it, Dr. Larsen? Yes. We have bean looking at various shots, and the one piece of data that is most complete inén the underground, which, es nest of you probably imow, is about a 1.2 KT. What we did there wan to tale soil flats from California soil representing § inches in depth, and abeut i #q. feet each box was in this dimension, and we distributed this over the territory of predicted fallout. We came back with helf of what we hod distributed as contaminated, which we could measure by survey meters, I'11 take one, which represents one of the naxinua activities to illustrate what we found. Wa had 196 sicrecuries total surface activity on 12/17/51, and we have gram 5 orope of radishes consecutively on that and ah the observed values, for example, On January 15, 1952, was 16.9 disintegrations per second per gran of plant dry material. The last crop came off in 9/19/52, of radishes, and this read 1.12. Row the controls that we had growing on the same soil, but without any centamination, reed, in this crop 1/15/52 series, it was 1.69 d/a/gram and over here 9/15/59 we sere getting about Ze ep WOE ARCHIVES