Figure 14Whole body counter record of evidence that a cyclotron worker has picked up higher-than-average quantities of radioactive zinc-65. Note how the graph shows peaks at specific energy levels identifying the radionuclides.
Figure 14Whole body counter record of evidence that a cyclotron worker has picked up higher-than-average quantities of radioactive zinc-65. Note how the graph shows peaks at specific energy levels identifying the radionuclides.
Figure 15Graphic evidence that a radioactive gas accidentally inhaled by a worker at an experimental reactor contained 3 radioactive isotopes of iodine.
Figure 15Graphic evidence that a radioactive gas accidentally inhaled by a worker at an experimental reactor contained 3 radioactive isotopes of iodine.
Figure 16The number of 1.38-Mev gamma rays emitted by sodium-24 in the body of a reactor accident victim indicates he received about 900 rads of neutron irradiation.
Figure 16The number of 1.38-Mev gamma rays emitted by sodium-24 in the body of a reactor accident victim indicates he received about 900 rads of neutron irradiation.
Figures14through16illustrate the kind of data that whole body counters provide to help physicians care for people involved in accidents.
Figures14through16illustrate the kind of data that whole body counters provide to help physicians care for people involved in accidents.
Similarly, neutron bombardment of natural sodium (²³Na) atoms in the body produces sodium-24. This reaction is written: ²³Na(n, gamma ray)²⁴Na. The 1.38-Mev gamma rays emitted by sodium-24 are detected effectively by whole body counters. Since a given neutron dose converts a known proportion of ²³Na atoms to ²⁴Na, it is possible to determine how much neutron exposure a worker has received by obtaining his body count of radioactive sodium.
Crystal type counters also were used in an interesting special case of excessive radiation exposure. Seven natives of the Marshall Islands were examined by the whole body counter at the Argonne National Laboratory in 1957. Another whole body counter, mounted in a Navy amphibious landing ship, was taken to Rongelap Atoll in the Marshalls several times to check on the health of all the residents of the atoll. These people had accumulated zinc-65 in their bodies as a result of contamination of crabs and other food items by fallout from the March 1954 atomic bomb tests at the Pacific Proving Ground. Although normal radioactive decay progressively reduced the total amount of radioactivity in the area, the Marshallese still were carrying this nuclide in their bodies after several years. (SeeAtoms, Nature, and Man, another booklet in this series, for a more complete report of this study.)
Study of the transfer of nutrients and other substances from an expectant mother’s body to that of her unborn child is one of the most challenging areas of biological research. A team of scientists headed by N. S. MacDonald has used a whole body counter at the University of California at Los Angeles to study one aspect of this problem by comparing the concentrations of radioactive materials in newborn infants, in babies who are born dead, and in tissues of the mothers-to-be.
In these studies the scintillation crystal was placed directly beneath a plastic bassinet holding the babies. Twenty-eight infants, 6 to 24 hours old, were counted for 45 minutes each. The only radionuclide found was the ever-present potassium-40.
The bodies of seven stillborn babies were counted for at least 10 hours each. More kinds of radionuclides were found than in the living babies, although the large counting time may have affected the results.
The same counting techniques were used with placental tissues from mothers of three of the stillborns. The placenta is the organ that nourishes an unborn child and through which substances from the mother’s bloodstream are exchanged with those in the baby’s blood. The graphs inFigure 17show data from this experiment and illustrate the method of interpreting whole body counter data. When the counts per minute at each band of gamma-ray energy recorded from the placental tissues (b) were subtracted from corresponding values from the stillborns (a), it was found (c) that the placentas contained more of the isotopes ruthenium-103, ruthenium-106, and zirconium-95 than did the babies that had been nurtured by these placentas. The babies’ bodies contained more niobium-95 and potassium-40 than the placentas. Niobium-95 is produced by the radioactive disintegration of zirconium-95. This suggested that zirconium-95 atoms do not pass readily through the placenta, but, after they have decayed to niobium-95, they pass into the baby’s bloodstream easily.
Actually, the gamma-ray energies of zirconium-95 and niobium-95 are so similar that the counter cannot distinguish between them. The two isotopes, however, were separated chemically, and whole body spectra were prepared from samples of the pure elements. The spectrum (d) of pure zirconium-95 subtracted from that of pure niobium-95 was strikingly similar to the spectrum of “stillborn baby minus placenta” on the graphs. Cesium-137 was added to the synthetic spectrum to provide a reference mark at the 0.660-Mev point. This revealed that the ratio of cesium-137 to potassium-40 is lower in babies than in adults.
Figure 17Results of experiment studying transfer of nutrients from an expectant mother to her unborn child.
Figure 17Results of experiment studying transfer of nutrients from an expectant mother to her unborn child.
Radioactive tracer atoms, either natural or purposefully built into molecules of vital materials like proteins, are revealing how these substances function in the body to produceenergy or to form new tissues. When we know accurately the normal totals and kinds of radioactive substances in the body, we can undertake new kinds of tracer studies without using large amounts of additional radiation. Small instruments called scanners (seeFigure 18) usually are used to track tracer isotopes, but whole body counters are useful in special circumstances.
Figure 18A multidetector positron scanner to record radiations with opposed pairs of detection crystals. Scanning devices are commonly used for noting the fate of tracer isotopes in medical diagnosis.
Figure 18A multidetector positron scanner to record radiations with opposed pairs of detection crystals. Scanning devices are commonly used for noting the fate of tracer isotopes in medical diagnosis.
Two types of adaptations enable whole body counters to locate accumulations of radioactive materials in specific organs or small portions of the body. At the National Institutes of Health, Bethesda, Md., one counter is fitted with three rows of six 12-by-12-inch plastic blocks. Each block has four photomultiplier tubes to collect the scintillations from the crystal. The rows are curved so as to be equally distant from the patient’s body.
The current pulses from each of the 18 blocks can be fed individually into the pulse sorter, counter, and recorder. Thus the kinds and numbers of gamma rays from the sector of the patient adjacent to any block can be studied individually. Similarly, the path and speed of the administered materials can be followed by taking recordings from the blocks sequentially.
At the U. S. Naval Hospital in Bethesda, Md., a whole body counter is fitted with a crystal that can be moved atcontrolled speed past the body of the person being studied (Figure 19). To increase its scanning efficiency, the crystal is fitted with a slit and a focusing device. Instruments record the body radioactivity visibly at timed intervals as the crystal moves along the patient’s body. A television screen enables the operator to observe the patient during the counting.
Figure 19The U. S. Naval Hospital whole body counter, showing the moving crystal, left, and instruments, including the television screen used by the operator. The moving crystal makes it possible to use this whole body counter for scanning.
Figure 19The U. S. Naval Hospital whole body counter, showing the moving crystal, left, and instruments, including the television screen used by the operator. The moving crystal makes it possible to use this whole body counter for scanning.
The role of iron in preventing one form of anemia has been clarified by using iron-59 as a tracer. Persons suffering from chronic infections or such blood diseases as leukemia and polycythemia vera have been checked for the amount of iron carried by their red blood cells. Cobalt-60 atoms have been substituted for stable cobalt in molecules of vitamin B-12 so that the way the body makes use of this vitamin can be studied. Similarly, the body’s use of sodium can be studied by labeling sodium chloride with sodium-22and then administering solutions of the tagged salt orally or by injection.
Whole body counters used in tracer studies cause a minimum of inconvenience for the patient. Their sensitivity permits use of smaller quantities of radioactive material than is required with small scanning instruments.
Those are unusual jobs for whole body counters, however. Scanners or other types of instruments are used more typically in following tracer isotopes.
Figure 20Dogs about to be examined in a whole body counter.
Figure 20Dogs about to be examined in a whole body counter.
How do dogs accumulate fallout isotopes in their bodies? This question was answered effectively by placing dogs in whole body counters and comparing the count from radioactive strontium-emitted gamma rays originating in their bodies with the count from a masonite phantom dog containing a known amount of radioactive strontium-85. It was found that female dogs increase their strontium retention while they are nursing newborn puppies. Strontium is much like calcium, which is a major component of milk. One dog measured had broken a leg in a fight. The counter showed above-average strontium accumulation for this dog, and it was conjectured that strontium, a “bone-seeking” element, had followed calcium to the point of bone repair and new bone growth.
Figure 21A wild deer under a whole body counter.
Figure 21A wild deer under a whole body counter.
Figure 22Graph of whole body counter survey of four different animal species, showing differences in their retention of orally administered radioactive zinc-65.
Figure 22Graph of whole body counter survey of four different animal species, showing differences in their retention of orally administered radioactive zinc-65.
Figure 22shows how animals differ in their retention of orally administered zinc-65, as revealed by a whole body counter. It is apparent that counters can be used to determine the differences in the metabolism of different animal species used for research. Standard data developed in this way can serve to reduce error that may occur if results from one species are used for interpretation of data for another species, such as man.
A University of Illinois project to breed meat animals with a high lean-to-fat ratio has been aided by whole body counters. The tendency to deposit fat seems to be inherited, and breeding stock with low fat content can be selected, using “muscle-seeking” potassium-40 to show the proportion of muscle in each potential parent. The Illinois counter is unique in being large enough to examine an adult steer (Figure 23). A similar counter at Cornell University has been used to study animals infested with internal parasites, comparing them with parasite-free animals. The counter revealed that a positive relationship exists between the level of parasite infestation and loss of iron-59-labeled blood from the digestive tract. The possibility of using this method to evaluate parasite-killing drugs is being considered. The Cornell counter is kept clean by covering the animals with plastic sheeting. The same counter also can serve human patients, who are positioned in a wheeled hospital stretcher. (SeeFigure 1D.)
This booklet has presented a sample of the ways whole body counters add to man’s knowledge and increase his ability to manage conditions and processes important to his health and well-being. Radioactive substances occur naturally within our own bodies and all other materials. Whole body counters measure this radioactivity, or any which may have been added from artificial sources.
We have seen how these sensitive instruments help to prove hypotheses difficult to verify otherwise and how they thereby may stimulate new and fruitful scientific experimentation. We have learned how whole body counters add to our knowledge of normal processes in healthy bodies and detect disease or abnormalities resulting from dangerous conditions.
Figure 23A University of Illinois counter large enough to examine an adult steer, above. A Cornell University counter used for animal-parasite studies, below.
Figure 23A University of Illinois counter large enough to examine an adult steer, above. A Cornell University counter used for animal-parasite studies, below.
Figure 23, below
Figure 24A trailer-mounted whole body counter used for research. School children were examined in a project to determine possible pathways by which radioactivity may enter the human body.
Figure 24A trailer-mounted whole body counter used for research. School children were examined in a project to determine possible pathways by which radioactivity may enter the human body.
Each fact uncovered by whole body counters seems to trigger more penetrating research. This is how science advances. And with the advance of science comes knowledge on which we may build intelligent behavior and find solutions to problems affecting our lives.
Environmental Radioactivity, Merril Eisenbud, McGraw-Hill Book Company, Inc., New York. 1963, 430 pp., $13.50.Radioactivity in Man: Whole Body Counting and the Effects of Internal Gamma Ray-Emitting Radioisotopes, George R. Meneely (Ed.). Charles C Thomas, Springfield, Illinois. 1965, 672 pp., $24.50.Whole Body Counting, Proceedings of the Symposium on Whole Body Counting Held by the International Atomic Energy Agency at the Neue Hofburg, Vienna (June 12-16, 1961), National Agency for International Publications, 317 East 34th Street, New York 10016, 1962, 535 pp., $10.00.How to Detect and Measure Radiation, Harold S. Renne, The Bobbs-Merrill Company, Inc., New York, 1963, 160 pp., $3.95.An Introduction to Radiation Counters and Detectors, C. C. H. Washtell, George Newnes Ltd., London, 1960, 115 pp., $7.50.Liquid Scintillation Counting, Proceedings of a Conference Held at Northwestern University (August 20-22, 1957), Carlos G. Bell, Jr., and F. Newton Hayes (Eds.), Pergamon Press, Inc., New York, 1958, 292 pp., $10.00.
Environmental Radioactivity, Merril Eisenbud, McGraw-Hill Book Company, Inc., New York. 1963, 430 pp., $13.50.
Radioactivity in Man: Whole Body Counting and the Effects of Internal Gamma Ray-Emitting Radioisotopes, George R. Meneely (Ed.). Charles C Thomas, Springfield, Illinois. 1965, 672 pp., $24.50.
Whole Body Counting, Proceedings of the Symposium on Whole Body Counting Held by the International Atomic Energy Agency at the Neue Hofburg, Vienna (June 12-16, 1961), National Agency for International Publications, 317 East 34th Street, New York 10016, 1962, 535 pp., $10.00.
How to Detect and Measure Radiation, Harold S. Renne, The Bobbs-Merrill Company, Inc., New York, 1963, 160 pp., $3.95.
An Introduction to Radiation Counters and Detectors, C. C. H. Washtell, George Newnes Ltd., London, 1960, 115 pp., $7.50.
Liquid Scintillation Counting, Proceedings of a Conference Held at Northwestern University (August 20-22, 1957), Carlos G. Bell, Jr., and F. Newton Hayes (Eds.), Pergamon Press, Inc., New York, 1958, 292 pp., $10.00.
Fundamental Nuclear Energy Research, A Special Report of the United Stales Atomic Energy Commission(December 1963), Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402, 407 pp., $2.50. Whole Body Counters as Medical Aids, pp. 11-13; Acute Whole Body Irradiation Effects, pp. 35-41; Chronic Whole Body Irradiation Effects, pp. 42-48.Radioactive Contamination of Materials Used in Scientific Research, James R. DeVoe, Nuclear Science Series Report No. 34, National Academy of Sciences—National Research Council, Washington, D. C. 20418, 1961, $2.00. Appendix VIII, The Negotiations and Developmental Work on Low Activity Glasses for Use in Whole Body Counters, pp. 109-115.
Fundamental Nuclear Energy Research, A Special Report of the United Stales Atomic Energy Commission(December 1963), Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402, 407 pp., $2.50. Whole Body Counters as Medical Aids, pp. 11-13; Acute Whole Body Irradiation Effects, pp. 35-41; Chronic Whole Body Irradiation Effects, pp. 42-48.
Radioactive Contamination of Materials Used in Scientific Research, James R. DeVoe, Nuclear Science Series Report No. 34, National Academy of Sciences—National Research Council, Washington, D. C. 20418, 1961, $2.00. Appendix VIII, The Negotiations and Developmental Work on Low Activity Glasses for Use in Whole Body Counters, pp. 109-115.
Liquid Scintillation Counting of C¹⁴ and H³ Labeled Amino Acids and Proteins, M. Vaughan and others,Science, 126: 446 (Sept. 6, 1957).Phosphorescence in Liquid Scintillation Counting of Proteins, R. J. Herberg,Science, 128: 199 (July 25, 1958).Suspension Counting of Carbon-14 in Scintillation Gels, B. L. Funt and A. Hetherington,Science, 125: 986 (May 17, 1957).Liquid Scintillation Counting of Aqueous Solutions of Carbon-14 and Tritium, J. Shapira and W. H. Perkins,Science, 131: 414 (Feb. 12, 1960).Alone in the Dark with a Panic Button: Purdue’s Whole Body Counter, Martin Mann,Popular Science, 181: 90 (October 1962).Counter as a Test Instrument, W. H. Bucksbaum,Electronics World, 68: 48 (November 1962).Spiral Capillary Plastic Scintillation Flow Counter for Beta Assay, B. L. Funt and A. Hetherington,Science, 129: 1429 (May 22, 1959).
Liquid Scintillation Counting of C¹⁴ and H³ Labeled Amino Acids and Proteins, M. Vaughan and others,Science, 126: 446 (Sept. 6, 1957).
Phosphorescence in Liquid Scintillation Counting of Proteins, R. J. Herberg,Science, 128: 199 (July 25, 1958).
Suspension Counting of Carbon-14 in Scintillation Gels, B. L. Funt and A. Hetherington,Science, 125: 986 (May 17, 1957).
Liquid Scintillation Counting of Aqueous Solutions of Carbon-14 and Tritium, J. Shapira and W. H. Perkins,Science, 131: 414 (Feb. 12, 1960).
Alone in the Dark with a Panic Button: Purdue’s Whole Body Counter, Martin Mann,Popular Science, 181: 90 (October 1962).
Counter as a Test Instrument, W. H. Bucksbaum,Electronics World, 68: 48 (November 1962).
Spiral Capillary Plastic Scintillation Flow Counter for Beta Assay, B. L. Funt and A. Hetherington,Science, 129: 1429 (May 22, 1959).
Available for loan without charge from the AEC Headquarters Film Library, Division of Public Information, U. S. Atomic Energy Commission, Washington, D. C. 20545 and from other AEC film libraries.
Understanding the Atom: Radiation Detection by Scintillation, 30 minutes, black and white, sound, 1962. Produced by the Educational Broadcasting Corporation under the direction of the AEC’s Division of Isotopes Development. This semitechnical film describes the scintillation process. Solid and liquid scintillators are shown, a description of a photomultiplier is given, and the pulse-height analyzer principle is illustrated.Human Radioactivity Measurements, 9 minutes, color and sound, 1958. Produced by AEC’s Los Alamos Scientific Laboratory. This film shows a method developed at LASL to monitor possible intake of radiation by personnel. The liquid scintillation counter is large enough to contain a man and sensitive enough to detect even the minute amounts of his natural gamma radioactivity.Ionizing Radiation in Humans, 15 minutes, color and sound, 1958. Produced by AEC’s Argonne National Laboratory. Describes the design and operation of ANL’s whole body counter for determining identification, quantity, and location of internally deposited radioelements. Various techniques in accumulation of data are shown.Liquid Scintillation Counting, 14 minutes, color and sound, 1958. Produced by the Jam Handy Organization for the U. S. Atomic Energy Commission. Describes the use of a liquid scintillator for counting low-energy beta emitters commonly used in biological and medical tracer experiments. Also describes counting techniques, how the counters work, and how a sample is prepared.
Understanding the Atom: Radiation Detection by Scintillation, 30 minutes, black and white, sound, 1962. Produced by the Educational Broadcasting Corporation under the direction of the AEC’s Division of Isotopes Development. This semitechnical film describes the scintillation process. Solid and liquid scintillators are shown, a description of a photomultiplier is given, and the pulse-height analyzer principle is illustrated.
Human Radioactivity Measurements, 9 minutes, color and sound, 1958. Produced by AEC’s Los Alamos Scientific Laboratory. This film shows a method developed at LASL to monitor possible intake of radiation by personnel. The liquid scintillation counter is large enough to contain a man and sensitive enough to detect even the minute amounts of his natural gamma radioactivity.
Ionizing Radiation in Humans, 15 minutes, color and sound, 1958. Produced by AEC’s Argonne National Laboratory. Describes the design and operation of ANL’s whole body counter for determining identification, quantity, and location of internally deposited radioelements. Various techniques in accumulation of data are shown.
Liquid Scintillation Counting, 14 minutes, color and sound, 1958. Produced by the Jam Handy Organization for the U. S. Atomic Energy Commission. Describes the use of a liquid scintillator for counting low-energy beta emitters commonly used in biological and medical tracer experiments. Also describes counting techniques, how the counters work, and how a sample is prepared.
This booklet is one of the “Understanding the Atom” Series. Comments are invited on this booklet and others in the series; please send them to the Division of Technical Information, U. S. Atomic Energy Commission, Washington, D. C. 20545.
Published as part of the AEC’s educational assistance program, the series includes these titles:
A single copy of any one booklet, or of no more than three different booklets, may be obtained free by writing to:
USAEC, P. O. BOX 62, OAK RIDGE, TENNESSEE37830
Complete sets of the series are available to school and public librarians, and to teachers who can make them available for reference or for use by groups. Requests should be made on school or library letterheads and indicate the proposed use.
Students and teachers who need other material on specific aspects of nuclear science, or references to other reading material, may also write to the Oak Ridge address. Requests should state the topic of interest exactly, and the use intended.
In all requests, include “Zip Code” in return address.
Printed in the United States of AmericaUSAEC Division of Technical Information Extension, Oak Ridge, TennesseeFebruary 1967
[1]This is mathematical shorthand for 1.08 followed by 24 zeros, or 1.08 million billion billion.[2]Medicines such as “Radithor” and “Radium Water” were manufactured and sold before it was known that overexposure to radioactivity was harmful.
[1]This is mathematical shorthand for 1.08 followed by 24 zeros, or 1.08 million billion billion.
[2]Medicines such as “Radithor” and “Radium Water” were manufactured and sold before it was known that overexposure to radioactivity was harmful.