B. ICRP 30 In ICRP 30, Supplement to Part 1 on page 414, the committed dose equivalent (CDE) per unit of activ- ty intake for bone marrow is given as 1.6 x1O ‘7 Sv/BcI fo r a gut transfer of 10-4. equivalent dose rate is 315 rem/pC -Y c. Based on these numbers the ● ORNL The value for bone marrow for a QF=20 of 0.90 rem/pCi-d is equivalent to 329 rem/pCi-y. D. UNSCEAR 1982 The UNSCEAR listed value of 0.008pGy/Bq is identical to the ICRp value of 1.6 x 107 Sv/Bq which I have already shown is equivalent to 315 rem/pCi-y. 3. Overall Comparison Spiers dose conversion for bone marrow of 338 rem/pCi-y is 7% higher than ICRP value of 315 rem/BCi-y. When these values for Spiers and ICRP are multiplied by the endosteal to marrow ratio of 12 and 13 respectively the resulting endosteal dose for ICRP numbers is 1% higher than that of Spiers. Thus, the two methods appear to be quite comparable for estimating the bone marrow and endosteal cell dose for Pu. 4. Our Method of Calculating the Marrow and Surface Cell Dose for Surface Deposited Pu. Starting with a pCi/d intake derived from the Pu concentration times an average dietary intake for each food item, we calculate, transfer factor of 10-4 and 45% deposition bone. This number is then multiplied marrow dose. in foods using a gut in bone, the pCi/g of Pu in by 338 rem/uCi-y to develop the bone The endosteal cell dose is then calculated by multiplying bone marrow dose by 12, the ratio of endosteal to marrow dose. 4 the