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We tried to determine—and I'll enumerate these atudies rather
quickly and then get on with the discussion aspects—the amounts and
kinds of radioactivity released into the environment. Obviously this
is important, but I would call your attention to the primitive nature
of the instruments and of the evaluation techniques that were avail-
able, particularly during the early years, We are inclined to think
in terms of what's available today rather than what was available in
the hectic years of 1943 te 1946, and even in subsequent years as we
went along. [ recall that we borrowed a scaler, an old Victoreen
scaler, from some of Dr. Warren's people and we would cut off a
piece of fish tiasue or some pieces of algae and push this material
inthe counter. If it went off scale we would say, “Well, there must
be some radiation there. Throw it away and push in the next one,"
{¢ was essentially a presence or absence situation in many instances,
There ways either some radiation or there wasn't,
I will have to qual-
ify my statement as to the determination of the amounts and kinds of
radioactivity, which came somewhat later,
We were particularly interested in the uptake of radioactivity by
biological systems and this again was ¢cependent upon good instru-
mentation, which, as [have said, wasn't available during the early
years. We were interested in the amounts and kinds of radiation
within various systems, the selectivity and the concentration. This
becomes germane when we begin to talk about permissible levels.
Some of the algal groups will take out one radionuclide; for example,
one will pick out iodine and concentrate it in the order of maynitude
of 18,000 times the amount in the surrounding water (Reference 37},
These blotting techniques then are very important to the overall evaluation because this alga is eaten by some of the fishes and the fishes
in turn then will contain the iodine. The most specific radiation dam-
age that has been measured directly is the destruction of the thyroid
‘in some of the algac-eating fishes,
DUNHAM: May I interrupt and ask you what kind of stable content
this does have normally?
DONALDSON:
of the dry matter.
DUNHAM:
In Asparagopsis, iodine constitutes 0.092 percent
Does it have a high iodine requirement for survival?
DONALDSON: I don't know the physiology of it.
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