- 36lonizing radiation is a linear function of dose regardless of dose rate
and have suggested that for each mr exposure per year to the entire pop-~
ulation of the United States there would eventually be an additional 10
cases of leukemia per year, i.e., about 40 cases per year as a result of
fallout.
Using this same reasoning there would be roughly an additional
3,333 cases per year were the population to receive 10 r of mn-mde
radiation every 30 years, tha exposure consistent with the recomnendations
of the N.A.S. Committee on Genatics.
It has alao been postulated that bone-seeking radioactive nucleids
such as radiostrontium might be leukemogenic.
The present average body
burden of Sr-90 in children in the United States is slightly less than
1/100th the mxinum permissible bone concentration for Sr~90 for ths
population as a whole.
This has been given as 0.1 microourie for an
adult, 1.6., 100 micromicrocurie per gram of calcium.
100 ppo/gram
ealcium would lead to an exposure to nearby bone marrow of about 0.14
rad per year, and that is, about 10 rad in a life time or less than 5
rad in 30 ysars.
If Lewis! hypothesis is correct, that leukemia induc~
tion is linear with dose to the bone marrow, and were all the bone mrrow
to receive this cose, which 1t doss not, such a body burden for all
people in the United States could mean an additional 510% increase in
leukemia (500 to 1000 cases) each year.
There is a considerable body of
experimental data Indicating thet with large single doses leukemia does
not result if a fair fraction of the hamatopoletic system is shielced
from total bedy radiation,
“ith a certain type of mouse lymphom, even
shielding one extrentty of the aninual will vitiate the leukemegenic