Айзек Азимов - The Genetic Effects of Radiation

Mutagen–Induced Gene Mutation. The narrator of this film is Hermann J. Muller, who won a Nobel Prize in 1946 for his work in the field of genetics. The measurement of X–ray dose in roentgens and the dose required to double the spontaneous mutation rate in Drosophila and mice are discussed. The magnitude and meaning of permissible doses of high–energy radiation are discussed. Other mutagenic agents (ultraviolet light and chemical substances) are discussed, concluding with comments on the importance of gene mutation in the present and future.

Selection, Genetic Death and Genetic Radiation Damage. The narrator of this film is Theodosius Dobzhansky, the coauthor of this booklet. Genetic death is discussed in detail, as are examples of how genetic loads are changed subsequent to radiation exposure. While it is generally agreed that the great majority of mutants are harmful when homozygous, more evidence is needed about the beneficial and detrimental effects of mutants when heterozygous. In the case of sickle cell anemia, heterozygotes are adaptively superior to normal homozygotes. This makes for balanced polymorphism, by which a gene is retained in the population despite its lethality when homozygous because of the advantage it confers when heterozygous.

Gene Structure and Gene Action. The lecturer of this film is G. W. Beadle of Cornell University. The Watson–Crick structure of DNA is discussed in terms of mutation. Several tests of the chain separation hypothesis for DNA replication are described (experiments with heavy DNA, radioactive chromosomes, and the replication of DNA in vitro). This working hypothesis is presented: The coded information in DNA is transferred to RNA, which serves as a template for polypeptide synthesis.

Dr. Asimov’s photograph by David R. Phillips, courtesy _Chemical and

Engineering News_

Page

4 James German, M.D.

6 Bausch & Lomb, Inc.

12 James German, M.D.

20 Indiana University

24 Robert C. Filz, Air Force Cambridge Research Laboratories

25 J. K. Boggild, Niels Bohr Institute, Copenhagen University

26 Brookhaven National University

28, 31 Herman Yagoda, Air Force Cambridge Research Laboratories

41 Oak Ridge National Laboratory

Dr. Glenn T. Seaborg, Chairman

James T. Ramey

Dr. Gerald F. Tape

Dr. Samuel M. Nabrit

Wilfrid E. Johnson

ONE OF A SERIES ON UNDERSTANDING THE ATOM

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 United States Atomic Energy Commission provides this booklet to help you achieve such understanding.

Edward J. Brunenkant

Edward J. Brunenkant

Director

Division of Technical Information

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:

NUCLEAR POWER AND MERCHANT SHIPPING

PLUTONIUM

OUR ATOMIC WORLD

NUCLEAR ENERGY FOR DESALTING

CONTROLLED NUCLEAR FUSION

WHOLE BODY COUNTERS

PLOWSHARE

POPULAR BOOKS ON NUCLEAR SCIENCE

SNAP, NUCLEAR SPACE REACTORS

NUCLEAR REACTORS

ATOMS, NATURE, AND MAN

MICROSTRUCTURE OF MATTER

SYNTHETIC TRANSURANIUM ELEMENTS

COMPUTERS

RESEARCH REACTORS

GENETIC EFFECTS OF RADIATION

POWER FROM RADIOISOTOPES

NONDESTRUCTIVE TESTING

RARE EARTHS

FOOD PRESERVATION BY IRRADIATION

FALLOUT FROM NUCLEAR TESTS

RADIOACTIVE WASTES

RADIOISOTOPES IN INDUSTRY

ATOMS AT THE SCIENCE FAIR

RADIOISOTOPES AND LIFE PROCESSES

ATOMIC FUEL

ATOMIC POWER SAFETY

DIRECT CONVERSION OF ENERGY

CAREERS IN ATOMIC ENERGY

RADIOISOTOPES IN MEDICINE

ACCELERATORS

NUCLEAR TERMS, A BRIEF GLOSSARY

NEUTRON ACTIVATION ANALYSIS

ATOMS IN AGRICULTURE

POWER REACTORS IN SMALL PACKAGES

Single copies of any booklet may be obtained free by writing to:

USAEC, P. O. BOX 62, OAK RIDGE, TENNESSEE 37830

Requests for more than three titles generally can not be honored.

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 publications on specific topics related to 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.

IMPORTANT : All requests should include the “Zip Code” in the address to which the material is to be mailed.

Printed in the United States of America

USAEC Division of Technical Information Extension, Oak Ridge, Tennessee September 1966

For more detail about cell division, see Radioisotopes and Life Processes , another booklet in this series.

This is more commonly known as “Mongolism” or “Mongolian idiocy” though it has nothing to do with the Mongolian people.

Actually, all waves have some of the characteristics of particles and all particles have some of the characteristics of waves. Usually, however, the radiation is predominantly one or the other and little confusion arises under ordinary circumstances in speaking of waves and particles as though they were separate phenomena.

For more about this subject, see Radioisotopes in Industry and Radioisotopes in Medicine , companion booklets in this series.

For more about this subject, see Fallout from Nuclear Tests , another booklet in this series.

For details on somatic effects of radiation, see Your Body and Radiation , a companion booklet in this series.

Estimated average exposures to the gonads, based on 1963 report of Federal Radiation Council.

One thousandth of a rem.

Nevertheless, it should be pointed out that the precautions taken in the atomic energy industry are such that absorption of radiation is not as severe a problem as one might suspect. Fully 95% of those engaged in this work receive less than 1 rem a year. Only 1% receive more than 5 rems.