and a factor of verhans one half might be necessary to allow for high spots. The dose estimates in parts C & D are based on contimous ingestion of 1) over the entire period. If ingestion ceased after about 30 days, but the D9? remained in the thyroid, the dose would be amaller; an estinate only will be made here of another factor of about 8/9. However, 4t must be euphasized that the dose from the [~”, which ia as large as the total r", dose, 4s received within the spase of several half lives of Te”, or about 9 days, while that dus to PY? 45 recedved during about 3 days ant tron 195 4n approximately 1 day. These exposures have been enlculated asmiing they cormenced at 3.5 hrz it ds of izportance din calculating the uptakes of short lived merlides to fix this tine. It is evident that the totals sould have been as high as 9,000 rep, and probably exceeded 4,500, This is still conservative, considering the thyroid damage observed in the samples. Fe Activit the The irradiation of the bone marrow may be estirated utilizing the uptakes of total fisaion products calculated in C and D. The isotopes Srey, Sr9O, Sr9l, Y9O, Yl, Bal4O and Lal4O will be considered here. Rather than total doses or dose rates, concentrations in gc for the whole aninal will be estimated, as it is felt that these figures are more sasily interpreted. The data on uptake and retentdongiven by Hamilton (/) will be used as a basis for evaluating their relative importance. Data on radioactive decay and chain relationships are from ref (3). TC" ARGHIVES