Radon

“ Induced Radioactivity.—Radium, thorium, and actinium have the property of acting externally, apart from the Becquerel rays that they emit. They communicate little by little their radioactive properties to substances in their neighborhood, and the latter emit in turn Becquerel rays. The activity can be transmitted to gases, liquids, and solids. The phenomenon is known as induced radioactivity.
Induced radioactivity propagates itself in gases step by step by a sort of conduction, and is not at all due to direct radiation from the body which causes it. ”

“ Norman said. "What's going on exactly?"
"Free radiation got into the fuel tanks," Failles explained. "You know that, of course. It started a chain reaction in the liquified fuel. The stuff degenerates slowly until it reaches a critical stage, then goes all at once. About a billionth of a second. Worse than that, it spreads through the rest of the metal parts. They begin to break down slowly, releasing energy in the form of heat or light, sometimes both. The light radiation kills, the heat corrupts the metal until it gives way, melting or crumbling depending upon its nature. ”

“ Relative penetration of alpha, beta, and gamma radiation.
For comparison, a sheet of paper stops alpha particles, a block of wood stops beta particles, and a thick concrete wall stops gamma rays.
9
In one way or another, the key to the usefulness of radioisotopes lies in the energy of the radiation. When radiation is used for treatment, the energy absorbed by the body is used either to destroy tissue, particularly cancer, or to suppress some function of the body. Properly calculated and applied doses of radiation can be used to produce the desired effect with minimum side reactions. ”

“ 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. ”

“ Radium is not alone in having these properties. Many having other radioelements are known already, the polonium, the mesothorium, the radiothorium, the actinium. We know also radioactive gases, named emanations. There is a great variety of substances and effects in radioactivity. There is always a vast field left to experimentation and I hope that we may have some beautiful progress in the following years. It is my earnest desire that some of you should carry on this scientific work and keep for your ambition the determination to make a permanent contribution to science. ”

“ We have seen that a salt of radium that has been freshly prepared possesses an activity which increases with the time, and becomes about five times as great as the initial activity. It seems that the emanation emitted by the radium can escape only with difficulty from the solid salt, and that it accumulates there and is transformed at once into induced radiation. An equilibrium is established when the spontaneous loss becomes sufficient to compensate the production. ”

“ 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. ”

“ Water is decomposed into hydrogen and oxygen. If moist radium chloride or a salt of radium containing water of crystallization is sealed in a glass tube, the gradual accumulation of hydrogen and oxygen will burst the tube.
The radiations rapidly decompose organic matter with the evolution of gases. Thus grease from stopcocks of apparatus used with radium or paraffin will give off carbon dioxide. Under an intense alpha radiation paraffin or vaseline become hard and infusible. ”

“ In spite of the rapid change he was going through, the greenish hue remained to mar his features with a ghastly pallor caused, no doubt, by the radio-active power of the radium. As for myself, I could feel no change in my physical being. I wondered if the great radium deposit was to blame. I knew that science held transmutation of elements possible and has even accomplished it in a small way and that radium itself is the product of disintegration of uranium and ionium. ”

“ The emanation from that little speck of radium is powerful enough to penetrate its porcelain holder and charge the water with its curative properties. From a tap at the bottom of the tank the patient draws the number of glasses of water a day prescribed. For such purposes the emanation within a day or two of being collected is as good as radium itself. Why, this water is five thousand times as radioactive as the most radioactive natural spring water.”
“You must have control of a comparatively large amount of the metal,” suggested Kennedy. ”

“ Ionizing radiation in low intensities is part of our natural environment. Such natural radiation is referred to as background radiation. Part of it arises from certain constituents of the soil. Atoms of the heavy metals, uranium and thorium, are constantly, though very slowly, breaking down and in the process giving off alpha rays, beta rays, and gamma rays. These elements, while not among the most common, are very widely spread; minerals containing small quantities of uranium and thorium are to be found nearly everywhere. ”

“ 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. ”

“ These experiments brought clearly to light the enormous energy, compared with the weight of matter involved, which was emitted during the transformation of the emanation. It can readily be calculated that one kilogram of the radium-emanation and its products would initially emit energy at the rate of 14,000 horse-power, and during its life would give off energy corresponding to about 80,000 horse-power for one day. It was thus clear that the heating effect of radium was mainly a secondary phenomenon resulting from the bombardment by its own α-particles. ”

“ Lizards avoid the direct rays of the noonday sun on the desert, and we ourselves take precautions against sunburn and sunstroke.
The same division into good and bad is to be found in connection with other forms of radiation—forms of which mankind has only recently become aware. Such radiations, produced by radioactivity in the soil and reaching us from outer space, have also been with us from the beginning of 2 time. They are more energetic than sunlight, however, and can do more damage, and because our senses do not detect them, we have not learned to take precautions against them. ”

“ These veins are veins of pitchblende which are found hardly anywhere in Europe except in the north of Bohemia and which are worked near the little town of Joachimsthal. And those radioactive bodies are uranium, thorium, helium and chiefly, in the case which we are considering . . ."
"Radium," François interrupted.
"You've said it, my boy: radium. Phenomena of radioactivity occur more or less everywhere; and we may say that they are manifested throughout nature, as in the healing action of thermal springs. But plainly radioactive bodies like radium possess more definite properties. ”

“ What one usually knows instead, is the roentgen dosage to a piece of tissue, which consists of many cells. If the charged particles inducing the ionization are electrons (as they are when the primary radiation is a beta ray or a gamma ray) , the ionization will be distributed more or less uniformly among the cells in the affected neighborhood. If the charged particle is heavy—a proton or an alpha ray—the density of ionization which it produces is much greater, so that some cells receive a good many more ion pairs, while others nearby may receive none. ”

“ We find that if the paint is old, compared to the 22-year half-life of the lead, let’s say 100 years old or more, then the amount of radioactivity from the lead-210 in the sample of paint will be equal to the amount of radioactivity from the radium in the sample. ”

“ 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”. ”

“ RADIUM (from Lat. radius, ray) , a metallic chemical element obtained from pitchblende, a uranium mineral, by P. and Mme. Curie and G. Bémont in 1898; it was so named on account of the intensity of the radioactive emanations which it yielded. Its discovery was a sequel to H. Becquerel’s observation in 1896 that certain uranium preparations emitted a radiation resembling the X rays observed by Röntgen in 1895. Like the X rays, the Becquerel rays are invisible; they both traverse thin sheets of glass or metal, and cannot be refracted; moreover, they both ionize gases, i.e. ”

“ Radioactivity is characterized by the kind of particle emitted from the nucleus (our examples, so far, have been of beta and gamma particles) , by the energy possessed by this particle, and by the half-life in which the radioactive decay takes place.
The biological hazard from radioactivity depends on all three of these characteristics. No matter whether the radioactive nuclei are produced in an atomic explosion or in an atomic reactor, some time will in general elapse before a human population can become exposed. ”

“ If in the interior of any body there is, owing to any cause, a continuous and constant evolution of heat, the heat accumulates in the body and the temperature rises until the loss of heat by radiation and conduction is in equilibrium with the constant gain of heat.
In general, except under certain special circumstances, the activity is not propagated through solid bodies. When a solution is kept in a sealed tube, the loss by radiation alone takes place, and the radiating activity of the solution is of a higher degree. ”

“ It cannot be said that any one form of collector is superior all round. Flame collectors blow out in high winds, whilst water-droppers are apt to get frozen in winter. At first sight the balance of advantages seems to lie with radium. But while gaseous products and even falling water are capable of modifying electrical conditions in their immediate neighbourhood, the “infection” produced by radium is more insidious, and other drawbacks present themselves in practice. It requires a radium salt of high radioactivity to be at all comparable in effectiveness with a good water-dropper. ”

“ It seems from this that the emanation experiences some particular difficulty in escaping from radium which is in a vacuum.
Disengagement of Gas by the Salts of Radium. Production of Helium.—Giesel noticed that solutions of radium bromide continually give off gases. These gases are principally hydrogen and oxygen, in the same relative proportion as in water, and might, therefore, come from the decomposition of the water of the solution. But Ramsay and Soddy also showed that there always is a small quantity of helium that they detected by its spectrum in a Geissler tube. ”

“ The background radiation to which we are exposed varies for some unexpected reasons. It has been pointed out recently that brick may contain more natural radioactivity than wood. The difference between living in a brick house and living in a wood house could give rise to ten times as much radiation as we are currently getting from fallout. (The additional radiation from the brick might be as much as 0.03 roentgens per year.)
Human beings are subject to radiation not only from natural sources, but also from man-made sources. ”

“ This part of the radioactivity is disseminated world-wide and completely escapes the control of man. To be sure, by the time this radioactivity is distributed over a large fraction of the earth’s surface, the dosage levels of radiation are very tiny, less than a ten thousandth of a roentgen for a megaton explosion. There is no danger whatever that a person would die or even become 96 mildly sick from this amount of radiation. There is, however, the possibility of long-range effects such as bone cancer, leukemia, and genetic mutation. ”

“ Radioactivity may enter the body as contamination in the food we eat or in the air we breathe. To be dangerous, however, it must remain in the body, either in the intestines or the lungs or in other vital organs, long enough for disintegrations to occur, which will ionize and injure the living cells.
Fortunately, plutonium in our food is easily excreted from the body. Only a few thousandths of a per cent of what is eaten, is actually absorbed. If inhaled, large particles are stopped in the nasal passages. Small particles get into the lungs but are quickly exhaled. ”