RADIATION STANDARDS, INCLUDING FALLOUT
81
Representative Price. Doctor, has there ever been a recommendation about doing something to improve our adequacy of detecting
fallout over the oceans?
oo.
Dr. Macura. Yes; this has been considered in the Division of
Biology and Medicine. It is a tremendous job; not only is the radiochemistry difficult because of the low concentrations, but the oceans
are very large and the sampling program expensive. A sea water
sampling program is under consideration in the Fallout Studies
Branch.
Representative Price. In your prepared statement you speak of
a lack of unanimous agreement among meteorologists. What are
the main points on which meteorologists have divergent views and
what are their implications in regard to fallout ?
Dr. Macuta. One difference of opinion can be used as an example.
Several people believe that there is a circulation, a net flow ofair,
from the equatorial region toward the polar regions of both hemispheres. There is another group which believe that the transfer
takes place from the equatorial to the polar region by mixing proc-
esses. It would appear that the results which from the Soviet 1961
tests would tend to support those whobelieve that mixing is the main
process.
;
However, in terms of practical results, the forecasts which are
made by both of these groups appearto be similar. So it is more of
an academic than a practical difference.
Representative Pricer. Mr. Ramey?
Mr. Ramey. At the time of our 1957 hearings, the main theory or
the official theory that was expounded wasthe so-called 10-year residence time and equal fallout in the Southern as well as the Northern
Hemisphere. This was pretty muchthe theory, as we understood it,
as expounded by Dr. Libby. What has happened to that theory? Is
that theory the one that is being applied only for the highest altitude shots, and these in the lower stratosphere are not working out
that way?
Dr. Macuta. Very definitely the evidence now suggests that injections made in the polar regions are coming out much faster than with
a meanresidence time of 10 years. This is agreed upon by everyone,
and you sawthe data for this earlier today. Most people, I think,
believe that even injections made in the equatorial region, except at
very high altitudes, are probably deposited at a rate faster than the
10 years just referredto.
At the time Dr, Libby made his estimates many years ago, there
were incomplete data and he made his predictions on the best information then available. The present data would suggest that the fallout. is depositing faster than the fallout rate estimated by Dr. Libby
many years ago.
Representative Pricer. Are there any questions?
Chairman Hortrterp. .A veryfine presentation, Doctor.
Representative Price. Are there any other questions?
If not, thank you very much, Doctor. You certainly presented a
very valuable paper to the committee.
We are glad to haveit.
The next witness will be Dr. Cyril L. Comar, Department of Physi-
cal Biology, Cornell University.
Dr. Comar.
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