fe
particle problem.
¢ ate
The question is: docs such a particic have an enhanced
potential for cancer ?
No one knows.
evolve from dead cells,
carcinozenic.
.
One can argue that cancer cannot
hence a depleted cell population must be legs
This is believeable, and must be true on occasion.
The
facts are, though, that intense , local doses of radiation are extremely
eficcui.c carcinogens, mucn more so than if the energy weie averaged
_over a larger tissue mass (Geesaman,D.P., 1968b)
Furthermore, this
can take place at high doses of radiation where only one cell in ten thousand
has retained its capacity to divide.
The cancer susceptibility of lung tis-
sue to radiation has been demonstrated in many species; one can say in
Some very
careful skin experiments of Dr. Albert have indicated that tissue
disrup-
tion is a very likely pathway'of radioactive induction of cancer after intense
_ exposure (Albert, R.E., et al., 1967a, 1967b, 1867c, 1969). The experiments showthat the most severe tissueinjury is not necessary, nor even
optimal, for the induction of cancer. When these notions are applied toa
t
.
.
. hot particle in the lung, the possibility of one cancer from 10, 000 disruptive particles is realistic. This is disturbing because an appreciable
portion of the total radioactivity in a plutonium aerosol is usually in the
large particle component.
Let me dernonstrate what I mean.
°
Suppose a man received a
hota permissible ung burden fer plutonium, and suppose roughty
pee"
.
:
.
.
.
recr the anass of the burdest was associated
with the most active class
ee wk weet tte
particles and implants than it is to diffuse uniform radiation.
eo
——
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Fades UrearbiARIathena
general that the lung is more eusceptible to inhomogeneous exposures from