30 March 1955
Dr. Willard F. Libby
Department of Chemistry
University of Chicago
Chicago 37, Illinois
I see that you and I have been put in the position of apparently being on opposite
sides in an argument, in the article in U.S. News and World Report of 25 March 1955.
You are quoted as saying "The world is radioactive. It always has been and always
will be. Its natural radioactivities evidently are not dangerous and we can conclude
from this fact that contamination from atomic bombs, small in magnitude or even of
the same order of magnitude as these natural radiations, is not likely to be at all
Perhaps it is not justified to say that the natural radiations evidently are not dangerous.
In his paper on the genetic effects of high energy radiation of human populations
Professor A. H. Sturtevant, who is one of the most able and experienced geneticists
in the world, writes that "In particular, there is evidence that irradiation does
increase the incidence of leukemia and other malignant growths." Some biologists,
at any rate, think that at least some kinds of cancer are produced by somatic mutations
induced by naturally radioactive potassium, carbon, and perhaps other elements, as
well as by cosmic rays. If this is so, there is little doubt that artificial radioactive
substances introduced into the body would also produce these malignancies.
Herman Muller in his 1950 article in The American Scientist, Kurt Stern in Science
of 31 December 1954, and Sturtevant all point out that these radiations without doubt
produce harmful mutations. In general these mutations are recessive, so that their
most seriously harmful effects do not show up in the first generation.
Do you have an argument to show that there is no danger that these effects are occurring?
I note that U.S. News and World Report states that radiation exposure to each individual
from all tests to date averages no greater than that produced by one chest x-ray.
The point here is that everybody in the world receives this exposure, whereas only
a few people are given chest x-rays. Moreover, the geneticists are disturbed about
chest x-rays Sturtevant says "In general, the conclusion seems warranted that the
medical 'use of x-rays is dangerous, and should be applied with caution and with full
realization of the genetic hazards involved."
I shall be interested to read what you feel about my remarks in this letter.
Ava Helen and I are safely back in Pasadena, after some great experiences during our
trip around the world.
With best regards, I am