Neal O. Hines

“ Although his experience with radioactivity has been brief, man probably already knows more about the effects of radiation than he knows about the effects of many other contaminants that alter his environment. ”

“ Nuclear tests, although not the only sources of man-made radioactivity, have been until now the most significant ones and the only sources touching large areas of the earth. The total product of nuclear testing is small in relation to the natural burden of radioactivity, raising the level of radiation to which all life is subject by a factor of one-tenth or less. But it is the unknown element, the degree to which fallout radioactivity may introduce new influences into the environment, that gives concern. ”

“ But, in the course of his experiments, man has come to realize that environmental and biological studies, which now are necessary because of the use of atomic energy, may help solve not only the problems atomic energy creates but also the larger problem of how to manage wisely the world’s limited natural resources. ”

“ When radioactivity is injected randomly into the atmosphere by a nuclear detonation, biological disposition begins in many ways, each related to the character of the explosion and the environment in which it occurs. Fallout studies thus involve the tracing of mixed fission products in the biosphere and the collection and analysis of thousands of samples of plant and animal tissue, and usually of water and soils, at many successive times. The radiobiologist then attempts to interpret the accumulated evidence of uptake of radionuclides. ”

“ Scientists at the AEC’s Oak Ridge National Laboratory, for example, have developed experiments in which an analog computer is programmed to keep a running balance of the net changes—simultaneous gains and losses—of radioactivity in the various compartments of a representative ecosystem. The computer becomes an electronic image of the biosphere, using known or assumed rates of energy transfer and photosynthesis to predict probable radiological results of tracer experiments of environmental contamination. ”

“ Environmental problems are best approached in the environment itself, where all the natural variables and 7 unknowns are present. Laboratory work is essential, but no laboratory can carve from nature or reproduce artificially all the complexities of the natural environmental “laboratory”, the ecosystem. [6]
Environmental studies frequently demand the coordinated attentions of ecologists, [7] chemists, physicists, geologists, oceanographers, meteorologists, botanists, zoologists, and others, all working together to approach the environment as a synchronized mechanism. ”

“ Hemispheric fallout introduced quantities of long-lived radionuclides, particularly cesium-137, into the food chains and consequently into the diets of native peoples. In each instance there had occurred a slow accumulation of radionuclides in the lichens and mosses and in other plants that are the foods of the reindeer and caribou. The meat of these animals forms a substantial part of the human diets, and as a result the members of the native communities were found to have, on the average, body burdens of radioactivity approaching the acceptable limit for human populations. ”

“ The case of carbon-14 is an example of a permanent man-made modification of the environment. From the early ages of the earth, carbon-14 has been created in the upper atmosphere by the transmutation of nitrogen in cosmic-ray reactions. Carbon itself is an almost universal component of living matter, and the ratio between stable carbon and radioactive carbon is believed to have been unchanged for thousands of years. ”

“ Other radionuclides [5] occur singly, rather than in families, and some of them, such as potassium-40 and carbon-14, are major contributors of natural radioactivity. Traces of natural radioactivity can be found, in fact, in all substances on earth.
When man began experimenting with atomic fusion and fission, he placed in his environment—across vast landscapes, in the oceans, and in the atmosphere—measurable additional amounts of radioactivity. These additions were composed of the longer-lived members of some 200 kinds of atomic radiation. ”

“ Understanding of the large cyclical forces has continued to elude us. We do not even yet grasp the small and seemingly random biological relations between individual organisms—relations involving predator and prey, for instance, and those among species and families—such as exist together in symbiotic [2] harmony and interdependence. Through centuries of observation we have gained a store of information. ”

“ Rivers present great differences in flow, and lakes vary in internal dynamics. Above all, an ocean, a river, or a lake is an area of constant physical and biological motion and change. In the ocean the surface waters form a theater of kaleidoscopic, and frequently violent, action. The presence of man-made radioactivity in water has made it possible to follow the disposition of nutrients and wastes in the restless aquatic ecosystem.
Biological Uptake
In a water environment the minerals necessary to life are held in solution or lie in bottom sediments. ”

“ Biologists are interested in every kind of living thing. When they study organisms in relation to atomic radiations, they enter the field of radiobiology, which really is not a science in itself but merely a branch of the larger interest in biology. Biologists find that atomic energy has significance both in the study of individual organisms and in studies of organisms in their natural communities and habitats.
Skin-diving biologist collecting giant clam from coral bottom of Bikini Lagoon in the Pacific Ocean. ”

“ The deer in the forest, the lizard in the desert burrow, and the peavine in the meadow are different kinds of organisms living in situations that are seemingly unalike. Each creature is part of its environment and a contributor to it, 3 but it also is part of the total biosphere. [1] All creatures are linked to each other, however remotely, in their dependence on limited environments that together form the whole of nature.
Gray shark photographed in another Pacific lagoon.
We know much about the life of the earth, but there is far more that we do not know. ”

“ Almost all places associated with nuclear programs have become focal points of research in environmental biology. Fallout, deposited in patterns determined by the mechanisms of the atmosphere, has created at certain points on the earth’s surface—the Arctic, for example—ecological conditions that require investigation. ”

“ The calf is her 15th to be born in 15 years. The cow, believed about 20 years old, has been under observation by scientists, who found she suffered little apparent effect, although the fallout caused some hair to turn gray (see light patches on back) . Other cows in the herd died natural deaths.
When a nuclear device is detonated, the release of energy is due to the fission of uranium or plutonium atoms or to the fusion of hydrogen atoms. At the instant of fission, some 75 radionuclides, or fission products, are created. ”

“ Radiobiological developments on land result from combinations of environmental influences. Studies in the Rocky Mountains show that ecological conditions above the timberline, particularly in areas where snowbanks accumulate, are efficient in concentrating fallout radionuclides. Concentrations thus take place in the snow-packed heights that are the sources of mountain streams flowing to the plains far below.
Atmosphere
The environment of the earth is a product of “weather”—of the transport of moisture, of the actions between winds and oceans, of the cycling of energy through biotic systems. ”

“ Determination of the amounts and kinds of radioactivity in a biological sample is a process wholly dependent on instruments, since radiation usually cannot be detected by the senses.
A biological sample is any material of measurable biological significance. A sample of tissue or similar organic material usually is dried or reduced to ash in a muffle furnace before it is examined with a radiation counting device. ”

“ Life on earth evolved amid constant exposure to ionizing [3] radiation, from the earth itself and from space, known as 4 background radiation. Therefore environmental studies must be conducted in relation to, and with understanding of, background radioactivity.
This Pacific Ocean coconut crab, member of a family that usually sticks to tide-covered beaches, depends on coconut trees for its food.
Of some 340 kinds of atoms that have been found in nature, about 70 are radioactive. ”

“ ATOMS, NATURE, and MAN
Man-made Radioactivity in the Environment
by Neal O. Hines
The Understanding the Atom Series
Nuclear energy is playing a vital role in the life of every man, woman, and child in the United States today. In the years ahead it will affect increasingly all the peoples of the earth. It is essential that all Americans gain an understanding of this vital force if they are to discharge thoughtfully their responsibilities as citizens and if they are to realize fully the myriad benefits that nuclear energy offers them. ”

“ The atom as a tool of the environmental radiobiologist has, of itself, solved few problems. Its significance is that it has speeded up—to a degree still not fully tested—our ability to study ecosystems and their relations to each other. ”

“ Bioenvironmental studies form a background against which all atomic energy research is conducted. The central objective of the Atomic Energy Commission’s environmental radiation studies is “to determine the fate and effect of radionuclides in the environment”. ”

“ There has been neither time nor opportunity, for example, to gather radiation-effects data on more than a few hundred of the 1,500,000 kinds of living organisms inhabiting the earth. Nor is it possible to predict the extent to which life can adjust itself to environmental changes resulting from scarcely perceptible alterations of natural radiological balances. ”

“ The distribution of residual radioactivity in the sea a month after the close of a nuclear testing program could be determined by counting radioactivity in plankton samples.
It was established that strontium-90 and cesium-137, important in fallout on land, enter the marine cycles only in minute amounts. Practically no fission products are found in fish. Since strontium-90 is not concentrated strongly by marine organisms, the question of what happens to it in the ocean remains unanswered. ”

“ The freshwater environment differs from the marine in the greater variety of its minerals, among other things. As sites for radiobiological studies, rivers and lakes present problems of great complexity, but conditions at river mouths or estuaries are even more difficult because of the mixing by tidal action of fresh and salt water. ”

“ Factors of biological transport and concentration of long-lived radionuclides make efforts to assess possible environmental effects particularly difficult. It has been asserted, for example, that probably every living cell formed since the early 1950s contains some of the radionuclides produced by nuclear testing. ”

“ Fallout radioactivity is assessed as a potential specific hazard to human populations.
2. Conditions created by fallout are examined for their potential long-term ecological significance.
3. Radionuclides introduced into the environment by nuclear tests, reactor operations, or other means are used as trace materials in basic studies in biological systems.
4. Radioactive forms of minerals and nutrients are deliberately introduced into biosystems—in measured amounts and under conditions of control—for studies of metabolic cycles and rates of flow of energy and nutrition. ”

“ Additional programs, large and small, are supported by foundations or other agencies. Work goes on in other nations. Many programs are international. Although only a fraction of this total activity is specifically related to environmental problems, the concern throughout is with the effect, for good or ill, of radioactivity on man and his world. It is possible to suggest by example the lines of inquiry.
A University of Georgia Research Institute ecologist studying biological specimens in a controlled environment near the AEC Savannah River Plant, Aiken, South Carolina. ”

“ The quantities of low-level long-lived radioactivity already released into our environment will provide materials for future studies covering decades. Further, because radioisotopes are chemically similar to nonradioactive forms, observation of their biological fate will provide clues to the transport, concentration, dilution, or elimination 6 of many other kinds of man-made toxic agents and contaminants of the environment. ”

“ Environmental studies at nuclear test sites or in controlled ecosystems involve not only long-term, periodic sampling of plants and animals but also years of detailed examination of soils, meteorological conditions, and other factors.
24 TERRESTRIAL ECOLOGY RESEARCH
An ecologist inspects cages placed around bagworm infestations of a red cedar tree that had been injected with radioactive cesium-134 to determine uptake of radioactivity in the larvae.
Checking pine seedlings exposed to ionizing radiation from a radioactive source (on tripod) in a controlled ecosystem. ”