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