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UNCLASSIFIED
BIOLOGY AND MEDICINE
expenditures for fiscal year 1957 given in the hearings on “The Nature of Radioactive Fallout
and Its Effects on Man,” held before the Special Subcommittee on Radiation of the Joint Committee on Atomic Energy during May and June 1957.
The bulk of the added expenditure for Project SUNSHINE for fiscal year 1958 over fiscal
year 1957 is the result of new programsfor stratospheric air monitoring, coastal fallout surveys, and broad soil-~climate-vegetation studies.
Monitoring and Sampling
.
The scope of the strontium 90 monitoring and sampling program is as follows: .
Stratosphere: United States and foreign —
Earth’s surface Gummedfilm: United States and foreign
Rainfall pots: United States and foreign
- Air filters; .UnitedStatés and foreign
-
' Soils: United States and foreign. .
Pasture program (soil, vegetation, animal bone):United States and foreign |
Milk: United States and foreign
Tap water: New York:
Canned ocean fish
Sea water: Pacific.
Food: United States and foreign
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Human bone: United States and foreign
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Some of these programs are discussed briefly below.
’ Stratospheric monitoring. Samples of stratospheric particulate matter are being collected
in an effort to determine the amount, latitudinal distribution and movement, and rate of fallout
of radioactive material retained in the stratosphere. Through contracts with General Mills,
Inc., and Nuclear Science and Engineering Corporation, and through a cooperative arrangement.
with the Air Force, a schedule of routine stratospheric balloon flights has been established at
Minneapolis, Minnesota, San Angelo, Texas, the Panama Canal Zone, and a location in the
southern hemisphere. At each station, efforts are made to obtain one sample each month from
each of four altitudes ranging from 50,000 to 90,000 feet. The samples are obtained by filter-
ing a determined volume of air through a large filter paper mounted ina cylindrical housing
which gives the program its title, “Project Ash Can.” A volume equivalent to at least 1,000
cubic feet of air, if it were compressed to standard density, must be filtered in order to obtain
a sample of particulate material large enough for radiochemical analysis. Because of thé great
expense anddifficulty involved in obtaining these samples, an attempt is made to learn as much
'as possible about their origin and history by analyzing them for two long-livedfission products,
strontium 90 and cesium 137; one relatively short-lived one, barium 140; and three with half-
lives of intermediate length, strontium 89, zirconium 95, and cerium 144, Samples for the -
first six months of operation have been analyzed, but interpretation in terms of radioisotope
concentrations in the stratosphere awaits the results of filterefficiency tests -in progress.
Becauseof the difficulties of collecting particles of the extremely small size found in the’
stratosphere at pressures of 1/100 to 1/10 atmosphere, it is necessary to conduct further research and development leading toward more efficient and reliable methods of collection. In
the search for an accurate sampling method for calibration purposes, the Chicago Midway:
Laboratories of the University of Chicago, under contract with the AEC, havedeveloped, con-
structed, and ground-tested a cryogenic device for liquefying air at altitudes up to 60,000 feet.
UNCLASSIFIED
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