The Relative Effectiveness of Neutrons From a Nuclear Detonation and from a Cyclotron in Inducing Dominant Lethals in the Mouse

Format is approximately 7 inches by 10 inches. Stapled twice on left side. Pages 269-286. Figures. Tables. Literature Cited. Stamp and ink notation on front cover. Stamped name of Donald J. Kimeldorf on front cover. Kimeldorf was an internationally renown scientist. Dominant lethality in the offspring of male mice exposed in lead hemispheres to neutron radiation from a nuclear detonation was determined for ten different doses by mating the males to unexposed females, dissecting the females at a late stage in pregnancy and recording the number of living and dead embryos, resorption sites and corpora lutea. Data from early matings (2 to 6 days after irradiation) and late matings (19 to 31 days after irradiation) were tabulated separately. Comparison of the results with those from a similar experiment with fast neutrons from a cyclotron shows: 1. For comparable levels of total effect, the two sets of results do not differ significantly in the distribution of deaths according to age of embryos. 2. The increase in dominant lethality observed when the offspring of late matings are compared with those of early matings is similar in the two experiments. 3. The biological effectiveness of detonation neutrons relative to cyclotron neutrons lies between 0.80 and 1.18, the minimum and maximum estimates obtained when allowance is made for uncertainty in the physical measurements of the gamma radiation contamination in the detonation experiment. It may be concluded that the present data show no significant difference in the effectiveness of these neutrons in inducing dominant lethality in mice. The authors were associated with the Biology Division and Mathematics Panel, Oak Ridge National Laboratory. William Lawson "Bill" Russell was born in Newhaven, on the south coast of England. He earned a scholarship to Oxford University. Upon graduating in 1932, he was awarded a one-year fellowship to Amherst College in Massachusetts. His work with Drosophila at Amherst encouraged him to apply for doctoral work under Professor Sewall Wright at the University of Chicago. He earned his doctorate in 1936 with a dissertation on physiological genetics of guinea pigs. During the latter part of the 1940s, Bill married Liane (Lee) Brauch, who would be his lifelong companion and coworker until his death. They moved to Oak Ridge, Tennessee, where Dr. Alexander Hollaender had established the Biology Division of the Oak Ridge National Laboratory. In Oak Ridge, they started a new research career. While beginning to plan his research, Bill asked Dr. Hollaender for a conventional-size mouse colony in order to continue his research. However, in the post-World War II era, there was much concern about possible hazards from the fallout of nuclear weapons tests and from peaceful uses of radiation. On the recommendations of the Nobel laureate Herman J. Muller and Sewall Wright a mouse genetics program was initiated in Oak Ridge. Therefore, Dr. Hollaender asked Bill Russell to investigate the genetic effects of radiation in mice. Dr. Hollaender and his advisers encouraged Dr. Russell to think big; the first floor of an old factory was developed into a very efficient mouse house. In 1951 W.L. Russell published the first results of his experiments: "X-ray-induced mutations in mice" (Cold Spring Harbor Symp Quant Biol [1951]: 16:327-336). In 48,007 offspring of irradiated males, 53-54 mutations were observed. In 37,868 offspring in the control group, only two mutations could be found. An experiment of such size was a new dimension in biology. Later the second and the third floors of the mouse house were developed, establishing a laboratory with impressive resources that was unique in all the world. He never published a paper specifically addressing the genetic risk of environmental exposure in humans, because he considered the business of risk estimation too risky. W.L. Russell participated in the United Nations International Conferences on the Peaceful Uses of Atomic Energy.…