evidence is not particularly helpful in deciding specific causation
in any individual."
Both of these statements are incorrect.
First,
it is well known that epidemiologic studies have documented that
radiation not only causes cancer but also that radiation causes
cancer of specific histologic type.
In fact,
there can be little doubt that, under a wide variety
of circumstances, ionizing radiation is carcinogenic and leukomogenic
in humans.
This conclusion is supported by numerous epidemiologic
studies conducted among human populations
diversity of exposure to radiation.
which have experienced a
Epidemiologic studies of
uranium miners exposed to alpha and gamma radiation have demonstrated
a large excess of bronchogenic cancer.
In addition,
have demonstrated a preponderance of a specific
these studies
histologic type of
cancer, viz small cell undifferentiated carcinoma, when compared to
the general population.
Epidemiologic studies of the survivors of
the atomic bomb explosions at Hiroshima and Nagasaki provide reliable
data on the carcinogenic effects of whole body exposure to camma rays
and neutrons.
Among those individuals,
and breast Cancer,
as well as leukemia,
an excess of lung,
thyroid
has been demonstrated.
This
excess of leukemia was shown to be predominantly of the myelogenous
and granulocytic type.
Conclusive evidence that therapeutic radia-
tion can be carcinogenic and leukomogenic comes from studies of
patients irradiated for ankylosing spondylitis, thymic
enlargement
and gynecological disorders.
In like manner, epidemiologic studies
have shown that radiologists
exposed to radiation have an excess of
leukemia when compared to other physicians not so exposed.