191 tary levels in the Chicago area. Proceedings
of the Second Conference on Radioactive
Fallout from nuclear weapons test. U.S.
Atomic Energy Commission, 1965.
19. Lowder, W. L., Beck, H. L., and Condon,
W. J.: Radioactive fallout from nuclear
weapons test. U.S. Atomic Energy
Commis-sion, Symposium Series 5. Washington, D.C.:
USAEC, p. 233, November 1965.
20. Vrenn, M. E., and Cohen, N.: Iron-55 from
fallout in the blood of adults. Health Phys.,
13:1075, 1967.
21. Joint Committee on Atomic Energy Hearings
on Development, Growth and Start of the
Atomic Energy Industry, 1965.
22. Eisenbud, M., and Petrow, H. C.:
Radioac-tivity in the atmospheric effluents of power
plants that use fossil fuels. Science 144:
3613, 1964.
23. Eisenbud, M. Industrial uses of ionizing
radi-ation. Amer. J. Public Health, 55:5, 1965.
24. Dunster, H. J.: The disposal of radioactive
liquid wastes into coastal waters.
Proceed-ings of the Second International
Confer-ence. Peaceful Uses Atomic Energy. Geneva:
United Nations, 1958.
DISCUSSION
DR. Lis: Opening the discussion for
Doc-tor Eisenbud’s paper is Dr. John N. Wolfe
of tile U.S. Atomic Energy Commission in
Washington. D.C.
DR. WOLFE: We have known for a long
time about the underlying unity of living
things, that is, the great fundamental
simi-larities among them; the concept reached a
degree of finality with Darwin’s enuncia-tion of organic evolution-still the greatest generalization in biology. Then it was
fur-ther emphasized with the development of
physiology, genetics, and ecology.
These also resulted in a union again into a biological discipline as over against the
familiar botany and zoology. The new
biol-ogy is based on integration, whereas the old
biology was based on ignorance-we didn’t
know enough botany and we didn’t know
enough zoology, but we put what we knew
or thought we knew all together. Today,
there is a considerable integration. Even
the buildings under construction over the
campuses emphasize the synthesis of the
life sciences.
Ecology and genetics are sort of
biologi-cal twins. The enormous advances that are
going on in genetics are based largely on
the enormous volumes of data to which
sta-tistical procedures can be applied. The ad-vance of ecology has not been as rapid, but one notion has developed in the past centu-ry which in a long view, I think, is probably
of equal importance to the advances made
in space and other technologies and the
ad-vances made in the knowledge of the atom
-in fact, these things may have contributrd to this biological phenomenon. This in sim-ple terms is that all things are related. Not only in matters of descent, not only in mat-ters of physiology and genetics, but also in terms of ecologic systems from pole to pole and around the world. And, these
relation-ships are preserved in varying degrees by
wind, water, ice, biotic migrations, and
food webs of incredible complexity.
Some-one has remarked that the growth of the
grass calls into play all the functions of the universe. One may challenge this for preci-sion, but it is an excellent guideline in these times when man is seriously contemplating his relations with his own environment.
Dr. Eisenbud has mentioned a
construc-tion project using nuclear explosives, such as another Panama Canal. If all that is done
is to cut a channel through an isthmus or
cut a channel anywhere, all that is
accom-plished is the digging of a ditch. That is
still ditch digging. The ecologic problems associated with such massive engineering
undertakings are exquisitely complex. Let
me say without being one of the doom
prophets (we have had them through the
whole length of history), we now have
some new considerations. We now have a
capacity to do engineering things of
enor-mous scope such as moving billions of tons
192
mountains, and the like. We now have the
capacity to do this in almost a twinkling;
and the debris from such undertakings can
be found around the planet, in the air, on
the land, in and under the water, and in
every living thing. If you don’t believe
these things happen, let me just raise one
question. \Ve have found pesticides and
fallout all over the earth. I have heard for 10 years, where do we put the waste? There
is only one answer to that. We are going to
have to find some way to utilize the waste
and research will answer that question. We
will never be able to dispose of it under a
dynamic ecosystem.
Dr. Eisenbud has told us of the sources
of radioactive materials and where they
are. I am reminded of the time when some
lady talked of the top soil of the Mississippi
Valley with the late Charles Kettering for
half an hour. She told him how many
mil-lions and millions of tons of Mississippi top soil was in the Gulf of Mexico and Charles
Kettering answered, “Well, we know where
it is, don’t we?” I really don’t think she got
his point. I think what he was thinking
about was that we have to find out how to
make the secondary soil work like the top
soil and quit worrying about what is at the
bottom of the sea. The situation is quite
different now in the terms of pesticides and
radioactive contaminants. A man might
spray an orchard in the Mohawk Valley and
after a while that material may be found in
a tuna fish in the South Pacific.
We have the fact that an organism can’t
live alone, nor does a species live alone, nor
does an unassorted population live alone;
its components must live together. and are
essential to each other. This integration, this synthesis, this amalgamation concept is
the biggest advance in ecology (the
ecolo-gists have known this for a long time). We
are talking about a world ecologic system
and this multiplies our problem and
de-mands a new approach.
So, the majesty of technology is not
sufficient unto itself. It is encumbered with
the responsibility of asking before its
ac-complishments what else these monumental
achievements do to the societies of man-in terms of well-being, safety, and basic bio-logical requirements of space, food, fiber, and shelter-all over the world.
DR. Lis: Also discussing Dr. Eisenbud’s paper is Dr. Wayne Black.
DR. BLACK: I shall discuss Dr. Eisenbud’s
paper from two viewpoints. I think it is im-portant first to reiterate certain facts that
have been presented, and, second, to
dis-cuss the relationship of these facts to public health and our society.
It was pointed out that radioactivity in
the environment arises from two sources:
natural radiation and man-made radiation.
What is not generally understood is that
natural radiation has been with us for bil-lions of years. The radioactivity from natu-ral sources which are biologically important
by virtue of the fact that they enter the
food and water chain, and ultimately man,
are potassium4#{176} and radiums”6 and “s. The radioactivity from artificial sources which
are important for the same reason are
cesium137, iodinel3l, strontium90, hydrogen’, carbon14, and zirconium95.
The dose received from radioactivity
arising out of weapons testing to date is far less than that normally received from
natu-ral radiation. However, this does not
pre-clude the importance of determining the
levels of specific radionuclides from all
sources as in the case of J131, which affects a primary target gland-the thyroid.
More recent studies on the levels of
in-digenous radium content of soils and water
in Brazil, India, and the United States
hopefully will provide an insight into the
effects of low level doses of radiation on
man. It might then be possible to determine if this low level exposure from natural radi-ation is responsible for an increased inci-dence of many diseases.
Data were presented which showed a
definite relationship between the amounts of iodine13’ and strontium9#{176} that resulted from
nuclear weapons tests and the levels of
these radionuclides which ended up in
var-ious tissues. For example, peak levels of
DR. FAmI: Will Dr. Eisenbud say
some-York City were found to correlate quite
well with predicted thyroid burdens. Milk,
which comprises approximately one third of
the average daily diet, was found to be the primary vehicle for the entrance of iodine into man and the iodine ultimately
concen-trated in the thyroid gland. From the data
presented, it was observed that the iodine burden per gram of gland in fetal thyroid
glands was several times that found in
young children. Certainly, at this time of
“life” the concentration of iodine by the
fetal thyroid gland appears to be due to
growth and development. Further studies to
determine what biologic effects occur in the
development and function of the thyroid
gland and other metabolic processes are
necessary.
As was the case with iodinel3l, strontium#{176}#{176}
is also passed to humans through the food
chain, particularly milk, though there is
bo-vine discrimination against strontium as it
passes along the pasture-cow-milk-men
pathway. Dr. Eisenbud pointed out that
strontium#{176}#{176}probably was overemphasized
at the expense of knowledge about the
be-havior of other radionuclides, namely
io-dine.’’ However, it should be noted that
the ridioactive half-life of iodinel3l is only
8 days, while the radioactive half-life of
strontium’#{176} is 28 years. Thus, looking into the future, strontium9#{176} will be present in
the environment for a long period of time
because of its long radioactive half-life. Io-dine131, fortunately, has decayed to unde-tectable levels at tile present time. Yet, the full physiobiologic effects of strontium#{176}#{176}still remain to be determined. Doctor Eisenbud’s data show the strontium9#{176} levels for the 2,000-year period were the highest of all. I think it appropriate to point out that further studies by several groups, particularly Doc-tor Rosenthal of St. Louis, have developed
some guidelines on information resulting
from strontium#{176}#{176}deposition in teeth, and on this basis they can relate back to the early 1950’s.
Other radionuclides have resulted from
weapons testing, which could serve as
sources of radiation exposure. These are
iron55, carbon’, and hydrogen3. Studies on the biologic effects of low level exposure
from these radionuclides might also be
ex-tremely important because a large part of
the iron in our bodies is associated with the red blood cells and because of the
ubiqui-tous nature of carbon and hydrogen in
hu-mans.
Two other sources of radioactivity that
might be considered as possible contribu-tors to the environmental contamination are
radiochemical processing plants and
nu-clear power reactors. At the present time
there is only one such radiochemical
pro-cessing plant in the United States.
How-ever, this may be a problem to be reckoned with in the future. Nuclear power reactors
are a special case. They can be designed
and constructed to have within their
opera-tion certain safeguards to make them only a
trivial source of environmental radioactivity. There are several natural and artificial
ways to reduce environmental radiation
ex-posure. The St. Louis County Health
De-partment has conducted studies which have
demonstrated that levels in milk of
iodine33’ and strontium9#{176} from fallout can
be reduced by 50% on dairy farms which
carry out optimal fertilization and land
management programs. This is an example
of natural reduction of radiation.
Artificial removal of radionuclides has
been accomplished by passing milk through
ion exchange resins. It was found that
iodine” could be removed by 35% and
strontium#{176}#{176}by 90%.
These and other techniques are both
fea-sible and practical for reducing or moving other radionuclides from the environment which might be dangerous to public health.
The use of nuclear energy in our society provides unlimited potential and possibili-ties. It becomes necessary now and impera-tive for the future to weigh the benefits to our society against the risks to public health
if nuclear energy is going to be a part of
our everyday lives.
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in relative biological significance of various radionuclides following detonation.
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Sr,-thing about carbon’ and tritium? These are
important constituents of the environment that need attention.
DR. STERNBERC. I would add zinc65 to the
list.
DR. BRILL: I was pleased to see Dr. Eisenbud’s data on the thyroid gland of tile fetus. It is important to recall that in lower animals such as the amphioxus, iodine is in-corporated and concentrated into iodotyro-sine molecules in the foregut region which
in higher organisms give rise to the
thy-roid gland. Thus, as the embryo recapitu-lates its earlier phylogenetic history, when the numbers of cells at risk of biological
damage are small even though levels of 1131
have not been detected in the few studies
of aborted fetuses conducted to date, the
hazard may be real at these stages. I
men-tion this not so much because of concern of
fallout exposure but to remind us that
diag-nostic and therapeutic uses of may be
most contraindicated in the first 12 weeks of fetal life prior to the appearance of rec-ognizable thyroid tissue. This reservation is
expressed since it has been suggested that
I” therapy is safe in pregnant women if
administered prior to the twelfth week of
pregnancy.
DR. BUSTAD: First, I am concerned about
Dr. Eisenbud’s single, high value of 700 pCi
per gram of thyroid in a 3-month fetus. I
harbor serious doubts about this value as
fallout derived at a time when the fetal thy-roid gland is just beginning to concentrate I13’
Second, relative to significance of the
various fission products at varying times
after fission. Dr. McClelland and I have
found useful a graphic summary of many
points presented by Dr. Eisenbud and Dr.
Black (Fig. 14). Would you comment for
others on the biological significance of
Ce’44 which seems so imposing in this type
of presentation?
DR. EISENBUD: These are all good points.
With respect to cerium144, the only place
we have found it is in the human lung. The
dose to the lung is certainly significant in relation to doses received by other organs. I agree with Dr. Bustad that cerium144 is im-portant and is often overlooked.
As for zinc65, I wish to point out that in the field of mensuration of radioactivity one deals with a range of units that probably is
equalled only in astronomy. From
megacu-ries to picocuries is a range of 1018. We
have a very powerful battery of tools with
which to measure radioactivity with
SUPPLEMENT
many radioactive elements present in the
environment that can be measured in
cer-tain parts of the world. It is found occasion-ally on the East Coast. Primarily, it seems
to be a minor constituent of reactor
effluents. However, the dose to people is
much smaller than that of other
radionu-clides discussed today.
I welcome the question regarding
carbon4 and tritium exposure. When the
dose from carbon’4 and tritium is
calcu-lated in the usual way, that is the number of rads produced, the dose is small. But, be-cause of the long life of C’4, the exposure to
C’4 is prolonged so the total dose to the
population is large. Moreover, both C’4 and tritium, because they are isotopes of carbon
and hydrogen, can be incorporated into
DNA. There remains the very important
question raised by Leipunsky in Russia and
Linus Pauling in this country as to how to
take into consideration the radioactive
atoms incorporated into chromosomal
structures. This results in a capacity to mu-tate the chromosome to a degree far greater
than expected if one simply calculated the
transmutation probability on the basis of
the ionization produced. This is a problem
that had not adequately been dealt with. It
is a problem that must be faced because
tn-tium in particular is being produced in
enormous quantities in the peaceful appli-cations of nuclear energy. It is a material that we are just beginning to be conscious of and it is very difficult to measure. Cu-riously, it was not known until the last few years that it is a fission product. It is
pro-duced by spallation in one of every ten
thousand fissions and is present in relatively
large amounts in waters discharged from
reactors and waste processes.
In answer to Dr. Bustad’s question of the
age of the fetus, it may not have been a
12-week fetus. Dr. Mochizuki estimated its
age by the crown to rump measurement.
The measurement was good. We were very
conscious of the fact we were doing work
on a very valuable piece of material. First,
the total radioactivity was measured. The
half-life determination confirmed that it
was iodine. The thyroid gland, weighing
about 20 mg, was dissected very carefully
from accompanying adnexal tissue; the
ra-dioactivity of the adnexa and of the gland
was measured separately and all of the
original activity was found in the gland. I
appreciate the fact that this single datum is startling. Since this is all the data we have,
I thought you should know of it.
The question of waste disposal is primar-ily an economic problem. There are a great
many ways to store waste so that it
pre-cludes contamination of the environment. They are expensive. In the future more eco-nomical ways will have to be found without sacrificing safety.
I am reluctant to discuss these things out of context of the general problems of
envi-ronmental contamination. I think that as
one looks at environmental contamination
in respect to nuclear power one ought to
remember that what one is trading is a few
millirads a year of radiation exposure for
exposure that comes from the discharge of
some 70,000 tons of sulfurdioxide. An
ex-traordinary concoction of chemical
ele-ments, which we know nothing about
rela-tive to biologic effects, are contained in fly ash being poured over our cities (for exam-ple, gallium, gadolinium, arsenic, cobalt,
chrominum). The ash of a coal fired plant
contains up to 20% thallium. From the
point of view of one who has been
inter-ested over the years both in environmental toxicology and environmental radioactivity, I personally would prefer to see a nuclear
plant in my community with a resulting
