See
RADIATION STANDARDS, INCLUDING FALLOUT
INE vets
17
you must save lives first and worry about long-range consequences
afterward. For if you do not save lives, the question of long-range
consequences becomes merely academic.
There are many other detailed facets under study by the NCRP
and ICRP, but I want to emphasize that they are mainly detail.
During the past 2 years no new information of a nature suchasto importantly influence our present protection philosophies or practice has
been developed. The initial work of the Russels, and now others,
indicates the existence of a dose-rate influence on certaingenetic effects
but the magnitude of the effect, while of great academic importance,
is not such as to warrant any relaxation of present standards. The
somatic effects of low-dose and low-dose-rate exposureis still the ma-
jor uncertainty in the establishment of radiations protection stand-
ardsfor the population.
.
Let me ‘emphasize two of the most important bases upon which our
whole radiation protection philosophy is founded: First, all radiation exposure of persons should be as low as possible commensurate
with our medical, social, and economic need; and, second, any risk
incurred as a result of radiation exposure is proportional to the dose
and there is no threshold below which risk vanishes. This latter is an
unproven assumption but is thought to operate in the conservative
direction.
In attempting to place radiation protection standardsin proper per-
spectiveit 1s important to break down the source of radiation exposure
into several categories. The choice will depend upon the end purpose.
Dr. Whipple has discussed this and if you will bear with me I would
like to go back over some of his ground from slightly different
angle.
he following is one possible breakdown :
(1) Natural radiation: Man has lived with it and must continue
to live with it—there is nothing we can do about it. It amounts
to roughly 125 milliremsper year.
(2) Medical irradiation: This represents probably the most clearcut example of a radiation use where the benefit far outweighs the
risk. Improvements in technique and procedure can and are being
made so that unnecessary exposure is being curtailed. In spite of the
reasonable expectancy that medical uses of radiation will expand,it is
probable that the average per capita dose will be further reduced.
The 1956 estimates of the average level of medical exposure in the
United States were such that it was thought to contribute some 150
millirems per pear or 120 percent of natural background average per
capita dose. Better evaluations made possible since 1956 indicate that
a more likely figure wouldbe in the range of 10 to 50 percent of backgroundor possibly less.
Chairman Hoxrrtetp. You are speaking about medical exposure
there; are you?
Dr. Tartor. Yes, sir; this is exposure to the patients.
Chairman Hotrrrerp. In other words, what you are stating is that
the average medical exposure is from 10 to 50 percent of the normal
background exposure ?
Dr. Taytor. That is correct, sir. The ealeulation of the percentages
are mine.
Senator AnpeRson. And the previous concept was that it was one
and fifth times the background ?
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