-9to the body from this material is approximately 0.01 mr/day
which is less than 5% of the radiation to the body from
cosmic rays ard the radium in the soil.
RADIATION EFFECTS IN MAN
In the present discussion, it is obviously impossible
to present in any detail the pathology of radiation injury.
This extremely complex subject has been voluminously developed in the medicai literature and is generally available.
The important radiation effects fall into two broad groups,
one pertaining to the individual himself and the second
related to questions of inheritance of the results of radiation damage to the germ celis.
The first category we may
call the somatic and the second the genetic effects.
Somatic Effects:
Here we must distinguish between the effects
of external irradiation and those of internally ingested bomb
residues.
With respect to the immediate region of the explosion and to the areas of close-in radioactive fallout in
the case of surface or near surface detonations let me say at
once tnat the external radiation hazard is overwhelmingly the
important one and the ingestion of radioactive bomb products
in this region is relatively trivial in comparison with the
external hazard.
The effects of external radiation are not qualitatively greatly different for the various types of nuclear
radiation but the regions and tissues of the body affected
are very much dependent upon the physical characteristics
and energies involved.
Thus the highly energetic gamma and
neutron radiations penetrate the entire body while the soft
gamma rays and beta radiation have only limited penetration
through the skin.
Alpha radiation is of no external consequence because of its extremely limited penetration.
The immediate effects of whole body gamma radiation
are determined by the dosage received and the rate of
delivery.
The systems most fundamentally affected are the
central nervous system, the blood forming organs and tissues
and the gastrointestinal tract.
The time of onset of
symptoms may vary from a few minutes for extremely high
doses delivered very rapidly to several weeks for smaller
doses delivered more slowly.
In general our previously
published figures for 50% lethality at approximately 400
(more)