RADIATION STANDARDS, INCLUDING FALLOUT
167
sian debris will not quite equal the exposure received from all past
weapons tests. Relative exposure from cesium 137, the external portion of it, is predicted as 46 millirads from all weaponstests prior to
the 1958 moratorium, and 28 from the Russian debris. Internal whole
body exposure from cesium and carbon 14, from all tests prior to 1958,
would be about 22, while the total from these two sources as a result,
of the Russian tests would be about 15.
.
Radiation of the bone marrow from strontium 89 and strontium 90
has been the primary concern in every hearing that has preceded this
one.
Help Dye ats.
sa TE
SSS
Estimates of the bone marrow doses were made onthebasis of
Dr. Kulp’s data on bone analyses using a 7090 computer program
at Los Alamos. The estimates indicate that the average doses to those
persons receiving the maximum would be about 250 millirads from
strontium 90 and 8 from strontium 89 from all tests prior to the 1961
Russiantests.
The Russian test in 1961 might be expected to almost double these
numbers making a total of ‘about 460 rads from strontium 90 and
strontium 89 from all weaponstests to date, excluding what is now
being detonated near Christmas Island by the United States.
The iodine 131 thyroid dose— prior to the 1961 Russian test—to a
large segmentof the children living in the population at that particular
time wasestimated by Lewis as 200 to 400 millirads.
The present Public Health Service estimate of iodine 131 exposure
from the U.S.S.R.tests is of the order of 140 millirads.
Let us take these separate numbers and add them up in the proper
way to give exposure from all weaponstests to those critical organs
or tissues which have been of principal concern. Let us compare that
with the only benchmark worth comparing it with and that is natural
background.
The 70-year accumulated bone dose from all weaponstests to date
according to our calculations would be about 670 millirads. The 70year dose to the bone marrow would be about 380 millirads. The 30year genetic dose according to our calculations would be about. 175.
The 70-year thyroid dose to children would be of the order of 650.
Nowlet us qualify these numbers to put them in perspective. First,
the predicted 70-year bone dose is about 6.7 percent of natural background. The marrowdoseis about 5.4 percent of natural background.
The 30-year gonad exposure is about 5.8 percent of natural back-
ground.
The thyroid dose to those children who had received the
maximum would all have occurred within the first year or two and
would be about 8 or 9 percent of what they would have received from
a 70-year natural background exposure.
Secondly, it is necessary to keep in mind that the estimated doses
are the maximum doses that will be averaged by the most susceptible
population. In other words, they. are the average doses to that particular segment of the population born at the right time to receive
the maximum exposure to the particular tissues, neither does it mean
that some person or persons might not receive considerably more or
considerably less. The way the doses have been calculated they apply
to a hypothetical population whose thyroid, bone marrow, and bone
were born at different times. They were born at that time which
would allowthem to accumulate the maximum exposure. That is why
we say it is a maximum average. You will find these numbers are
KORREF stn sty