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RADIATION STANDARDS, INCLUDING FALLOUT
STATEMENT OF LESTER MACHTA,’ CHIEF, METEOROLOGICAL
RESEARCH PROJECTS BRANCH, U.S. WEATHER BUREAU
Dr. Macuta. Mr. Chairman, if I may, I should like to submit my
written testimony for the record and devote my time to a discussion
of a few of the placards in order that the less technical aspects be
brought out in verbal testimony.
Representative Price. That will be all right. We may question
you little on the complete statement.
(The statement referred to follows:)
WORLDWIDE FALLOUT SINCE 1959—METEGROLOGICAL ASPECTS
Statement prepared by Dr. Lester Machta’? and Mr. Kosta Telegadas,’ U.S.
Weather Bureau, for the hearings on radiation standards, including fallout, of
the Joint Committee on Atomic Energy during the period June 4-7, 1962
The purpose of this presentation is threefold: First, to report observed inventories of strontium 90; second, to describe the latest findings of the seasonal
and geographical distribution of fallout; and third, to review current ideas on
the behavior of the stratosphere in transporting bomb debris.
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tidtie sags Sire TES whee OES
PREREsc tSoeeiehiry
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INVENTORY CALCULATIONS
i. Pre-Soviet 1961 inventory
Figure 1 displays the strontium 90 content of the atmosphere (divided into the
troposphere up to between 30,000 to 55,000 feet and the stratosphere overlying
the troposphere) and the worldwide strontium 90 fallout as of May 1961. The
table shows that over 80 percent of the strontium 90 had already been deposited
just before the Soviet 1961 resumption of atmospheric testing. It also indicates
that the stratosphere was still the prime reservoir of the airborne radioactive
debris.
Figure 1 further reveals an unexpected approximate equality of
stratospheric content between hemispheres. One should remember that all (or
almost all) of the stratospheric injections took place in the Northern Hemisphere. We shall later see that there are very meager data in the Southern
Henisphere, and it may be that equality is not entirely well founded,
Figure 2 compares the total observed inventory of strontium 90 at three times.
These numerical values show good stability and a decrease, during a period of
no additional injections, as expected from the slow radioactive decay of strontium 90, On the lower line, a similar series of numbers is given as derived from
the official AEC announcements on fission yields and using a conversion of 1
megaton of fission product energy equaling 0.1 megacurie of strontium 90.
Both the observed inventories and AEC derived estimates contain uncertainties. The observed data are based on only a limited number of sampling
> sy MeRAPA es
2Dr. Lester Machta: Dr. Lester Machta is Chief of the Meteorological Research Projects
Branch, Office of Meteorological Research, U.S. Weather Bureau, Department of Commerce.
Dr. Machta recefyed his Se. D. from Massachusetts Institute of Technology in 1948 at
which time he joined the Weather Bureau to begin his studies on atmospheric radioactivity.
He was a member of the U.S, International Geophysical Year Nuclear Radiation Com-
mittee, is currently a member of the World Meteorological Organization’s Panel of Experts
“gee
on Atomic Energy, and in 1958, went to Geneva with the U.S. delegation on atomic test
moratorium conference. As an adviser to the Atomie Hnergy Commission, he has
participated in several of the U.S. atomic series.
He has been an adviser on the U.S.
delegation of the United Nations Scientific Committee on the Effects of Atomic Radiation
and on the Working Group cf the Federal Radiation Council, He is a rapporteur for the
Meteorology Committee of the National Academy’s Committee on the Biological Effects of
Atomic Radiation.
Dr. Machta was born in New York, N.Y.. in 1919, graduated cum laude from Brooklyn
College in 1939. His meteorological training also includes graduate work at New York
University (master of arts, 1946). During the war he taught meteorology in both a
civilian and military capactty for the Air Force. He is a member of Sigma XI, Pi Mn
Rpsilon, the American Meteorological Society, and the American Geophysical Society, and
has been given a gold medal for exceptional service by the Department of Commerce.
His
publications in the meteorological literature are numerous, and in recent years, include
many papers on atomic energy and meteorology.
2 Kosta Telegadas: Meteorologist. U.S. Weather Bureau: Associated with atomic energy
and meteorology since coming to Washington in 1955. Born in New York, N.Y., in 1924,
graduated from New York University in 1950. His meteorological training includes
graduate work at New York University (master of arts, 1951}, and from 1951-55, as a
research assistant at New York University. He has served with the Fallout Prediction
Unit on Operations Redwing, Plumbbob, and Hardtack phases I and IT.