~ 22 =
entirely off the soil for their whoie growing period of 20
years or SO.
The food of ‘lowest strontium-90 content is fish
flesh, because of the great diiution the fallout rec wives
by the hundred meters of sea water above the thermoc-ine,
which rapidly mix with the failout.within a few hours or
days. This means that the specific concentration of radio-=
active strontium, or any other fallout constituent in sea
water, is relatively very much lower than it would be in
\
soil.
For example, 100 meters of sea water has 370 grams
of dissolved calcium per square foot as compared to the
average of 20 grams per square foot for the top 2.5 inches
of soil which absorbs and holds the fallout radiostrontiun.
Therefore, in principle sea food and fish are lowest among
foods in content of radiostrontium fallout.
IV.
EFFECTS OF CONTINUED TESTING AND GENERAL CONCLUSIONS
In summary, then, we see that the present body
burden of strontium-90 from atomic weavons tests in the
United States corresponds to the radiation dosage to the
bones which wouid resuit from a few
hundred feet increase
in altitude, and the present vital statistics show no
observable effect on the. occurrence of bone cancer or
leukemia of much larger changes in altitude.
The tolerance
figure of 100 Sunshine Units, or .1 of 4 microcurie for an
average individual, or 100 micromicrocuries ver gram of
body calcium, that is recommended now is about two hundred
times the present level for new bone in the U. &., and it
will not be exceeded by fallout from weapons tests in any
foreseeable circumstances.
The distribution of strentium-90 burdens among
individuals for a given locality will be a normal error
curve with a standard deviation of about one-third of
the average concentration. This means that about one ine
dividual in 200 wiil have more than twice the normal aver-=
age value for a given locality, and that about i in several
million will have three times the average value.
(more)