Part 5

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.

Showing RETENTION, % versus TIME, DAYS for Man, Dog, Rat, Mouse

Figure 22 shows 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. (See Figure 1D.)

CONCLUSION

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.

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.

SUGGESTED REFERENCES

Books

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.

Reports

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.

Articles

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).

Motion Pictures