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SC4E FURTHER CONSIDERATIONS ON RADIATION DOSAGE TO SHEEP FROM
FALL-OUT DURING THE SPRING 1953 NUCLSAR WEAPONS TESTS
A.
BEST COPY AVAILABLE
Intreductim
Caleulatics of radiatio dosage tothe thyroids of sheep ingest-
ing falleout have been made alsewhere (1).
It was thera concluded
that these doses were not Llarrs enon to account for deaths amonz
the animals.
It is centended here that althouth the activity found
in the thyroid serves as an index of total radiation exposure, tha
thyroid dose is but mea of several possible types of internal irradiation which will occur when inzestim of mixed fission products has
taken clace.
Ths most important of thes3 appears to te the dose to
the bone marrow fren long lived isctopes with 3low biological turnover.
This effsct has zensrally bien ocmsidersd to be chronic in character,
but it appears possible that "short term" effects may also occur if
th3 concentrations are gu:ficiently high and tho emitters are of
moderat ly Long half life.
Stronz evidences of bens mavrow damage hs
been fomd in sgauples taken froam the skeletcns of several of these
animals and subjected to histopatholotical examination (2).
This
accenpanies the avidence of thyroid and other damage also observed,
and is undcubtedly of sreat:r importance than the latter tothe survival
and wall veing of tha animal.
These observations and the calculatims
presented here constitute rather stron arguments Tor the conclusion
that radiation 2ffects played an important [role inyehp,decnesesdvs
mortality cbserved amonr the aninals.
CLASSFATGece
326 U...oRIss) ENERGY
nlRG
PROPrer
Or
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ty.wo.Caecek~ahste7
Dee9 MISSIO
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“4365
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