Effects of Radiation.
(UNCLASSIFIED)
Experiments at
National Laboratory have been continued on the effects of r
on animaits, In attempts to determine which of the many ce
making up injected bone marrow or spleen are responsible fo
of irradiated animals, the relative importance of granulopo}
erythropoietic cells has been evaluated by using equivalent fr
of bone marrow and spleen from normal mice; mice having chrqnic
abscesses and ulcers; and mce subjected to repeated hemrr
These tissues were injected intraperitoneally into mice exp
900 roentgens. The preliminary observations show a 790 per
vival with normal bone marrow, 66 per cent survival with bo
Showing hyperplasia of the granulopoietic elements, and 92
survival with bone marrow showing hyverplasia of the erythr
elements.
question of the role that bone tissue plays in recovery of
lethal doses of irradiation.
Approximately 50 per cent
recovery, additional studies will be made for verification
Toxicity studies were made of plutonium 239 with dogs}
and of
acutely lethal level, and the lowest dose used, 0.67 micro
kilogram, was above the tolerance level.
(2) After intr
injection some of the material remains at the injection si
lead to severe lesions in the area.
(3) Gross liver dama
observed in four of the five animals that lived 569 or mo
after the intramuscular injection of 5.0 microcuries/kilo
(4) Skeletal changes were seen in all animals that lived
or longer. These included demineralization of bone, pathd@logical
fractures, and neopiasia, Three malignant bone tumors ap#eared among
the animals that received 5.0 microcuries/icilogram intram
these were detected at 674 days, 830 days, and 1,393 days[
tively.
respec-
Intravenous injection of 0.67 microcuries/kilogram resulted
in a malignancy 1,5) days later.
Radiation Instruments Program
Scintillation Counter Symposium,
(UNCLASSIFIED) A fneeting was
held recently of the Joint Subcommittee on Nuclear Instruments of the
Institute of Radio Engineers and the American Institute df Electrical
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