- 10 Roentgens of immediate gamma radiation from the bomb still
seem accurate.
Transient depression of white cells and
platelets may be detected readily at an exposure of 50
roentgens, and nausea and vomiting will occasionally be
found with whole body doses as low as 100 roentgens.
Where the dose is delivered over several days, the
amount of radiation to produce death in 50% of those exposed
must be increased by a factor which is about two.
In the case of the local radioactive fallout in
the vicinity of a tomb expioded on the surface, about onehalf of the total possible radiation dose is delivered
within the first 24 hours.
Measures to prevent or limit
such exposure must therefore be undertaken promptly if
they are to be effective.
Exposures in the region of 200 roentgens of whole
body gamma radiation may cause such a depression of white
cells that antibiotics are required to block secondary
infections.
A decrease in platelets to below 30,000 per
cubic millimeter may lead to purpura requiring the use of
platelet transfusions, a procedure which is still experimental.
Whole blood transfusions, especially those from
many donors, introduce hazards such as those from incompatibility and from infectious hepatitis.
Save ina
situation of the utmost urgency, repeated small transfusions
from different donors may create more hazard than that from
the original radiation exposure.
During the last spring,
when nearly 300 Marshail Islands and Task Force personnel
were accidentally exposed in a fallout of the type discussed, no transfusions were used although in some cases
white blood cell and platelet counts reached disturbingly
low levels.
With conservative therapy and good nursing,
all have recovered and there have been no instances of
jaundice or liver involvement.
Gamma and neutron exposures near lethality may
also be expected to cause some delayed manifestations.
The joint Japanese-American studies by the Atomic Bomb
Casualty Commission at Hiroshima and Nagasaki have shown
that within the range of neutron flux there is an appreciable incidence of cataracts among the survivors.
Also
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