dose-effect data.
It would appear that the skin burns and temporary
epilation which occurred indicate
a surface dose from fall-out par-
ticles deposited on the skin to be equivalent to a dose in the order
of 10,000 rep of 0.5 - 0.7 mev beta.
The ratio of the intensity of
beta plus low energy gamma radiation at the surface of the skin, to
the high energy (above 80 kev), gamma component measured 3 feet above
the ground, in this situation approximates an effective beta/ganma
ratio of about 50/1.
It is felt that in spite of the wide range
covered, the foregoing beta/gamma estimates, extending from 2.5/1 to
140/1, are still reasonably compatible when it is considered what each
describes and how the measurements were made.
Thus, it should be pos-
sible to determine by comparison with known data a single procedure
for calculating a useful ratio of the unmeasurable beta plus low
energy gamma skin hazard to measurable gamma radiation in a fall-out
“Feld.
The Marshallese incident has pointed up the fact that beta burns
will occur at sub-lethal gamma levels only when particles come into con-
tact with bare skin.
According to laboratory hematological data on
these natives, the whole body gamma dose approached lethal levels, yet
these natives who, for the most part, remained in the open during
active fall-out, received burns limited to unclothed parts of the body
or in areas where perspiration carried contamination into clothed areas.
Beta radiation is known to have a carcinogenic effect” on the
skin.
Among the few relatively undisputed statemerts in this regard is
the observation that before a skin cancer has been observed in man,
evidence of radiation injury has been apparent.
This suggests that the
dose required to produce skin cancer is at least as high as the dose
required to cause observable skin damage.
Whether this observation
taken from chronic exposure cases holds true for acute exposures is
not known.
It would seem likely that because of the injury recovery
factor a much higher total dose must have been received in the chronic
* Carcinogenesis (the action of an agent upon a tissue producing
cancer, i.e. radiation)
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