Graph Four shows the number of microcuries of fission products ingested at times after detonation to produce 1.0 rad to the thyroid.
III.
89
Doses to the Bones
The three principal bone-seeking isotopes of concern are sr? - yy,
Sr“, and Ba
140
-Ia
140
.
Eveluation of these may be made in terms of amount
deposited in the bones versus maximum permissible body burdens, or in rads
of dosethat they deliver after deposition.
Since values for maximum per-
missible body burdens are based on the concept that these will be maintained
indefinitely in the body, they are not so valid for & 89 and BaltO_ tal?
when considering short periods of emergency intake.
The following principal assumptions are used in calculating the
doses to the bones of adults:
a.
The percentages of the isotopes of gr7?_y%, er, and Ba
140_,,tH40
in mixed fission products are according to Hunter and Ballau.?
b.
The percentages of intake of these isotopes that are deposited
in the bones, the energies of emissions, and their effective half lives
are according to reference five - except for sr90 where a@ 27.7 year radiological half life is used here.
c.
The mass of the bones is 7,000 grams.
DOE ARCHIVES
The method of calculation of doses to the bones is illustrated by
computing the dose from Sr
89
from the intake of 27 microcuries (See IV Dis-
cussion below) of mixed fission products on the 120th hour.
1401,140
culations were made for sr70_y90 and Ba
Similar cal-
and then the three doses
4