a other measured quantity, that of the dose rate, as about 20 mr/hr, a better value for either p or q must be chosen. Since p, the fraction retained, seems a conservative estimate at 0.2 amd is a fairly well known quantity, one can accept it and see what value of q would lead to the value of u(t, ) implied by the measured air dose rate, which is ult,) © 20(867) = 170p0/tt? Then a= Blt) 2 3, pAz(4;) 042(170)(0s0011) = a2 tt7/aay or a faster of about 4 ag noted. It is evident that when this is applied te the Shot 2 case, where only the dose rate in air at 3.5 hr is known, this increase in area covered will fnerease the dose estimate by the same factor. The figure of 2 ft”/day seems more reasonable than that of 20 tt/aay. If one keepe the assumption of 2000 gm total vegetation eaten per day by the sheep, this implies that the area contained about 25 gn/ft” of edible dry vegetation, Alternatively, the animal could well have eaten more than 2000 gm per day. It might of course be suggested that only a fraction of the f4ssion products present on each square foot of sof] was actually ingested, in which case the total ground covered would be necessarily greater. In any case, it is the product of such a fraction and such an area which is importants it is only necessary to assume thia “effective” area to be constant from day to day in both localities. This is probably not bad, sinee whether the same amount of -8- TOW ARCHIVES