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BIOLOGY AND MEDICINE
radiation dose and the inéidence of genetic mutations. Although this relationshi has not been
demonstrated at the low dose rates prevailing ‘in nature, the possibility of such A, relationship
penne fa
has led to the suggestion that geographical variationsin the frequency of spontaneous muta-.
tions may becorrelated ultimately. with differences in the natural radiation dogp to populations.
The July-September 1957 quarterly report described thepreliminary resufts of a study of -
naturalbackground radiation performed in August by a team from the Health a: d Safety Laboratory of the New York Operations Office. A report dated March 11 entitled “Hiternal Environ-
pS
mental Radiation Measurements in1 the United States” (HASL-25) presents the data andthe
team’s analysis.
7
In order to establish the» approximate range of population’exposures to cosdes ic and terrestrial gamma radiation, an effort was made to attain results which would be regresentative of
the unperturbed natural. background and which would be influenced as little as possible by the’
occasional substantial variations in the observed natural radiation levels prodiced by localized :
sources. Such sources might be ore bodies, granite buildings, brickpaving,’ aliout,; etc.
‘The measurements were made with a specially designed Yonization chamt e
of 17 daysduring the course of a roundtrip by automobile fromNew YorkCityt
ings were Fecorded from 154 locations in 19 ‘states.|
To account for the cosmic.ray contribution at the higher:altitude locationkin the mountain
-states, measurements were later made at corresponding altitudes along the ehst coast during
airplane and airship flights. In general, the terrestrial contribution to natura background Tadiation was found to be about60 to 90 millirads per year. The cosmic ray contribution was
found to range from about 30 milliradsat sea level to about-90 millirads at I enver, Colorado,
where the elevation is about 5,000 feet above sea level.
ACTIVITIES IN ATOMS FOR PEACE PROGRAM
Mobile Radioisotope Training Laboratory
—
‘
Preliminary plans have been drawn up for two mobile radioisotope tra ing laboratories
for presentation to the International Atomic Energy Agency. Each mobile laboratory would
consist of two units, a laboratory and a counting room, contained in a trailef. Thetwotrailer laboratories, accommodating a total of 12 students in each laboratowy session, would
cost an estimated $85,000. It is felt that a course can be presented that wogld be essentially
ALBEEABh SPE peers eee
Sep ret mers
Tas at AP sgbhoe tat Sep Fe ee
the same as the basic course given by the Oak Ridge Institute of Nuclear
the omission of an activation experiment.
St dies except for
It is planned to include the two mobile laboratories in the United Stated technical exhibit
at the International Conference at Geneva in September 1958. The laborato
presented to the International Atomic Energy Agency at the General Confer enceto be held in
Vienna shortly after the close of the Geneva Conference.
Inter-American Institute of Agricultural Sciences, Turrialba, Costa Rica
Under the AEC program for the support of agricultural research and fadioisotopes train- ing at the Inter-American Institute of Agricultural Sciences at Turrialba, Posta Rica, a°200curie gammairradiation source supplied by Brookhaven National Laborat ry has been: installed
ina gamma‘field constructed at the institute.
ne
Work continued in preparation for the course in radioisotope techniques to be offered for
the first time in the fall of 1958. A humidity-controlled room for counting equipment and a
Ui ELASSIFIED