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BIOLOGY AND MEDICINE
UNCLASSIFIED
Bone Marrow Studies
Bone marrow studies were made at Brookhaven National Laboratory Medical Department.
Five of the.exposed persons developed symptoms characteristic of the “hemotologic”type of
acute radiation syndrome. Three individuals did not show significant clinical signs or _
symptoms.
The mitotic index (rate at which cells divide) was determined by examination of the bone
marrow of all eight individuals. The cells were labelled with tritiated thymadine and studied
by autoradiography. Within four days the mitotic index dropped from normal levels (about
9 mitotic figures per 1,000 nucleated bone marrow celis) to less than 1 per 1,000. The decrease seemed to be dose dependent, and thus might serve as a biologic dosimeter. Abnormal
mitoses and severe morphologic changes in the cytoplasm and nucleus of blood cell precursors
were seen in the first marrow smear performed 12 hours after the accident. Tritiated thymadine was incorporated into myeloid and erythroid precursors indicating the presence of DNA
synthesis in remaining cells continuing after four days. The mitotic activity of the marrow of
the heavily exposed individuals reached minimal values within about 14 days and was back to
normal after 28 days. These findings indicate the possible value of bone marrow examinations
after a nuclear accident, both as‘an aid in estimating the effective dose received and for thera-
peutic considerations, since blood cell changes as seen in the peripheral blood reflect only
indirectly the effects on blood cell formation.
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DOSIMETRY OF RADIATION ACCIDENTS
The Oak Ridge National Laboratory is fabricating several hundred improved dosimeter
units of their own development, which are capable of measuring both gamma and neutron dose
resulting from radiation accidents. These units consist of threshold detectors and chemical
dosimeters for the measurement of neutron and gamma radiation dose respectively. The AEC
is making these units available to those groups within which the possibility of accidental
criticality excursions exists.
PROJECT CHARIOT ENVIRONMENTAL STUDIES
Field parties to conduct planned environmental studies reached the site of the proposed
harbor excavation in Alaska (Project CHARIOT) in June. Activities were stepped up during
July and August and decreased in September to what will be only intermittent operations
throughout the remainder of the year.
Project participation has now been extended to seven groups, each concentrating in areas
of their special competency. The University of Alaska is conducting investigations of the
flora, small land mammals, sea-cliff birds, human ecology, and exploratory archeology.*
Dr. Don Charles Foote is investigating human geography. The Arctic Health Research Center
and U. 5. Public Health Service are making studies of avian species other than the cliffdwellers, fresh water algae, and marine mammals. Hanford Laboratories (General Electric
Company) is conducting studies to analyze the effects of an atomic detonation on the structure
and balance of the ecosystems (the living organism in combination with its environment) of
fresh waters and their shorelines, and to study the transference of specific radioisotopes fro
the detonations through the ecosystems. The University of Washington and the U. S. Fish and
*Artifacts were excavated very close to the project site this summer and are being examined now i
an effort to date them. .
UNCLASSIFIED
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