202 Cellular Events Produced by Ionizing Radiations /I0 : 7 



recessives ; increased mutation rates are highly undesirable for mankind. 

 In contrast, the controlled use of ionizing radiations has greatly enhanced 

 genetic knowledge as well as made possible the production of better 

 plant species. 



Indiscriminate use of clinical X rays and increased fall-out from 

 atomic testing both can produce increased mutation rates. The present 

 fall-out levels are just at the limit where the generation of new cancers 

 and induction of the genetic effects might be detectable. Both of these 

 deleterious results would be manyfold worse among any population 

 surviving a nuclear war. 



REFERENCES 



1. Miner, R. W., ed., "Ionizing Radiation and the Cell," (Monograph) 

 Ann. New York Acad. Sc. 59: 467-664 (1955). 



a. Bloom, William, R. E. Zirkle, and R. B. Uretz, "Irradiation of Parts 

 of Individual Cells. III. Effects of Chromosal and Extrachromosal 

 Irradiation on Chromosome Movements," pp. 503-5 r3. 



b. Patt, H. M., "Factors in the Radiosensitivity of Mammalian Cells," 

 pp. 649-664. 



2. Hollaender, Alexander, ed., Radiation Biology: Volume I. High Energy 

 Radiation (New York: McGraw-Hill Book Company, Inc., 1954). 



a. Muller, H. J., "The Nature of the Genetic Effects Produced by 

 Radiation," pp. 351-473. 



b. Muller, H. J., "The Manner of Production of Mutations by Radia- 

 tion," pp. 475-626. 



c. Bloom, William, and Margaret A. Bloom, "Histological Changes 

 After Irradiation," pp. 1091-1143. 



3. Bovey, F. A., Effects of Ionizing Radiation on Natural and Synthetic High Polymers 

 (New York: Interscience Publishers, 1958). 



4. Bacqu, Z. M., and Peter Alexander, Fundamentals of Radio bio logy (London, 

 England: Butterworth & Co., Ltd., 1955). 



5. Tatum, E. L., "The Status of Gene-Enzyme Relationship," part II, 

 O. H. Gaebler, ed., Enzymes: Units of Biological Structure and Function (New 

 York: Academic Press, Inc., 1956) pp. 107-176. 



6. Zirkle, R. E., "Partial-Cell Irradiation," Advances in Biological and Medical 

 Physics, J. H. Lawrence, and C. A. Tobias, eds. (New York: Academic 

 Press, Inc., 1957) Vol. 5, pp. 103-146. 



7. Benzer, Seymour, "The Elementary Units of Heredity," A Symposium on 

 the Chemical Basis of Heredity, W. D. McElroy, and Bentley Glass, eds. 

 (Baltimore : Johns Hopkins University Press, 1957) pp. 70-93. 



8. U.S. National Committee on Radiation Protection, "Maximum Per- 

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 Permissible Concentrations in Air and Water," National Bureau of Standards 

 Handbook 52 (Washington, D.C.: Government Printing Office, 1953). 



