Robley Evans in the Wild West

This story appeared in the July 1996 issue of the Health Physics Society Newsletter.

Early on in life, Robley Evans left the State of Nebraska where he was born and made his way to Hollywood where he helped finance his education by playing drums in a jazz band. If he hung out at Schwab’s Drugstore, the entertainment industry ignored him and it was left to the Los Angeles County Health Department to discover his latent talents:

In late 1927, as Evans was about to enter graduate school at the California Institute of Technology (Caltech), Eben Byers, the well-known industrialist, aging playboy, and former U.S. amateur golf champion, fell out of his private berth in a Pullman train and injured his arm. The specialist Byers sought help from prescribed Radithor, “Perpetual Sunshine in a Bottle,” a potent elixir that delivered at least 1 µCi each of 226Ra and 228Ra per serving. The official explanation was that the Radithor would speed up the healing process. However, rumor had it that the real reason Byers took Radithor was to improve his performance, and we’re not talking about golf. In any event, Byers was so satisfied with the results (his arm got better too) that he continued to partake of Radithor until 1928, at which point the ensuing headaches and toothaches drove him once again to the medical profession. The diagnosis was that Byers’ body was decomposing (his teeth were already falling out) due to its massive amounts of incorporated radium. Byers’ last two years of life were agonizing. His widely publicized death finally came on 31 March 1932, at his Long Island mansion in the scenic Hamptons (Macklis 1980)—just as Robley Evans was finishing his doctorate at Caltech under Robert Millikan.

Radithor might have been produced in East Orange, New Jersey, but Los Angeles was the main breeding ground for companies producing radium-containing cure-alls, e.g., Zimmer Laboratories, manufacturer of the Zimmer Radium Emanator, “the perfect product,” and the Radium Appliance Company, producer of the Radio-Active Sta-Put Truss, “Supports While it Heals.” The large number of such companies in its jurisdiction prompted the Los Angeles County Health Department to seek advice from Robert Millikan (Evans 1984) when the shock wave from Eben Byers’ death reached the west coast. Millikan introduced the Health Department’s representative, Frank Crandall, to Evans and told Crandall to “Do whatever this young man tells you to do.” Well, Evans was just about to graduate and probably somewhat uncertain himself about what he wanted to do. As a result of Crandall’s visit and their subsequent collaboration, Evans’ interest was aroused in the metabolism of radium in the body and possible methods to speed up its elimination.

By late 1934, Evans had said goodbye to California and accepted a position on the Physics faculty at the Massachusetts Institute of Technology. Convinced that teamwork was more productive than individual effort, Evans immediately established a collaboration with Dr. Joseph Aub of the Harvard Medical School, who had recently admitted as an inpatient a Boston Society matron who had been injected with considerable quantities of radium as a cure for arthritis. Evans was eager to determine if he could speed up elimination of the incorporated radium by modifying her body’s calcium metabolism. Darn thing was, his equipment was still on its way from California. So Evans made a trip down “Mass” Avenue to Harvard University and borrowed a geiger müller (GM) detector from a friend who was investigating cosmic rays. News of this fine example of technology transfer immediately reached the Harvard office of public relations (which probably had an endowment equal to that of most small colleges). The Harvard public relations folks promptly alerted the news media, and the next day the morning tabloids hit the streets of Boston screaming the headline “Boston Savant Cures Radium Poisoning with Green Cosmic Rays.” (Evans 1984). Evans’ old mentor, Robert Millikan, would have loved it. The latter was so fond of the limelight that at Caltech they defined a Millikan as one thousandth a unit of publicity. But Dr. Aub, Evan’s new and senior collaborator, took a different view. The patrician world of the Boston medical establishment, he told Evans, didn’t approve of such shenanigans. Evans took this reprimand to heart and endeavored to keep a low profile for the rest of his career.

To evaluate the efficacy of various methods for eliminating radium from the body, Evans had to develop an accurate technique to measure the body’s radium content. The method he devised was the “meter arc technique” wherein the patient was placed one meter away from a GM detector. The patient’s body formed an arc with a radius of curvature of 1 meter (or, for the less supple, 1.5 meters) centered on the detector. Four counts were performed: one with the patient facing away from the detector; the second with the patient facing toward the detector; the third with several standard radium sources positioned behind the patient; and the fourth with the sources in position but no patient. Neat! Today, an almost identical method is used in many gamma spectroscopy labs to correct for self-absorption in soil samples! Evans’ meter arc device was the very first whole-body counter and the forerunner of the gamma cameras and scanners found around the world in nuclear medicine departments.

Evans’ next step was to improve the gamma sensitivity of his GM counter. To this end, he undertook a series of exhaustive investigations into the role of fill gas pressure and cathode construction (Evans and Mugele 1936). The result was a GM tube that used a copper screen as its cathode. The increase in the cathode surface area gave the detector double the gamma sensitivity of the traditional tube—something sufficiently marvelous that Lauriston Taylor (Taylor and Sauer 1984) remarked it was “so nice, it’s almost cheating.” Still, the achieved sensitivity presented a problem: the mechanical registers that were used to count the pulses had a long resolving time (ca. 0.1 second) and couldn’t handle the higher count rates. What to do? The solution came to Evans during a particularly good rally with co-worker Newell Gingrich in a ping pong game in Evans’ basement (Kathren and Ziemer 1980). Evans shouted, “I’ve got it!,” stopped the game and explained the concept to a skeptical Gingrich who didn’t think it would work. Perhaps, Gingrich was in a contrary mood because of the interruption to a game he thought he was about to win. In any event, the next morning Evans and Gingrich built a prototype. Lo and behold, it worked: the first direct reading count-rate meter (Gingrich et al 1936). They referred to it as a “speedometer.”

A couple of years later, in 1937 at age 30, Evans became a father. The joyful event took place at the Massachusetts General Hospital and the attending physician was Dr. Saul Hertz. Together with Dr. Hertz and Dr. Arthur Roberts, Evans helped give birth to the field of Nuclear Medicine. Using 128I produced by neutron activation, they demonstrated that the thyroid of a rabbit would accumulate radioactive iodine in a reproducible and quantitative way (Evans 1974). Furthermore, they demonstrated that the uptake of a hyperactive thyroid was several times that of a normal thyroid. Very quickly, they progressed to successful diagnostic uptake studies in humans and, beginning in January of 1941, the application of 130I to the treatment of thyroid disorders. Later, 131I would replace 130I and these techniques would help save the life of the mother of 131I's co-discoverer: Glenn Seaborg (Seaborg 1995). Of course, Evans’ contributions to nuclear medicine are well known. What is not so well known (or important, for that matter) is that the term “tagged,” as applied to radiotracers, made its first appearance in the paper by Hertz, Roberts, and Evans (1938) describing their initial study on rabbits. “Atomic cocktail” was the name given to the radioiodine solutions the patients were required to drink—the human patients that is. The solutions used in the preliminary studies with rabbits were probably called “atomic cottontails.”

One of the most commonly told tales of Robley Evans concerns the establishment of the 226Ra “tolerance level” of 0.1 µCi, the first limit on radioactivity in the human body and the benchmark for all subsequent limits on internally deposited alpha emitters (Evans 1984): In 1940, the U.S. was gearing up for WWII. Large numbers of radioluminescent dials would have to be produced for the military and Dr. Charles Stephenson of the Navy pushed Evans to establish safety standards for the radium dial industry. The group that accepted this task was a nine-man advisory committee on radium created by Lauriston Taylor from the National Bureau of Standards. Leon Curtiss was the committee chairman, but it was Evans who first proposed a limit on radium in the body: “I suggested that we set the ‘tolerance level’ for residual radium burdens in radium dial painters at such a level that we would feel perfectly comfortable if ones own wife or daughter were the subject. I then asked each of the other eight committeemen individually in turn if he would be content with 0.1 µCi. Unanimously, we all were.”

I must admit that my cynical nature was immediately aroused when I first read the preceding story. Why did Evans refer to wives and daughters, but not girlfriends? I couldn’t believe that all nine guys had daughters and that all were married. Most likely, I thought, none had daughters and if the nine committee members were married (something I doubted) they were in the process of getting divorced. Everyone at the meeting was probably having a good laugh at Evans’ joke. But, it turns out that I was completely wrong (a cynic knows the price of everything and the value of nothing): all four committee members for whom I could obtain data had been married and at least three, possibly all, had daughters.

All too soon after the tolerance level of 0.1 µCi was established, the U.S. became embroiled in WWII; Evan’s count-rate meter, combined with another idea of his, would play a tactical role in the North African and Italian campaigns (Taylor and Sauer 1984). During retreats, land mines were laid down to slow the enemy’s advance. Made of plastic, the mines were hard for the enemy to find, but they were also hard for our troops to find when the offensive had been regained. Evan’s idea was to impregnate fake pebbles (copied from originals scavenged from Boston’s North Shore) with 5 µCi of 60Co and drop a couple in the ground with each mine as it was being planted. However, Evans first had to calculate the exposure rate to a soldier carrying a backpack of these pebbles and put a limit on the activity that could be carried—a kind of maximum permissible external body burden. Later, when our troops were reconquering the areas they had mined, they located the mines with a count-rate meter and GM detector at the end of a stick—the kind of walkover surface scan that puts hair on your chest. ‘High voltage, don’t fail me now.’

Perhaps Evans’ biggest contribution to the war effort was the method he helped develop for preserving blood supplies (Peacock et al 1946; Taylor and Sauer 1984). At the start of the war blood supplies would only last for five days or so. When blood was needed, it had to be obtained from transfusions near the battlefield. Using a double tracer method employing 55Fe and 59Fe, (he later used a triple tracer technique involving 55Fe, 59Fe and 131I) Evans showed that blood preserved in a cooled acid citrate dextrose solution could last for up to 30 days—sufficient time for civilian blood to be collected and flown to the front. This technique continued to be used by the Red Cross for several decades.

Up till now, all of these stories are well documented. However, to my knowledge, the next story has never been written down. It was told to me by Dr. Evans in the summer of 1995. Since then, Bob Gallaghar has added a couple of details. It is the story of the very first radiation survey using a count-rate meter:

The year was 1936, or thereabouts. A radium-containing industrial radiography source had disappeared at a General Electric (GE) facility in Lynn Massachusetts and GE’s insurance company, Liberty Mutual, was immediately notified. To head off liability claims, Liberty Mutual contacted Evans at MIT and asked him to help locate the missing source. Evans packed up his count-rate meter, a long extension cord, and a GM detector, and off he went. Surveying the plant with his bulky equipment connected to long cables and running off AC current was a cumbersome process, but eventually Evans located a strong source of radiation coming from an unexpected location: a worker’s locker. When the locker was opened, the man’s clothes were inside and the radium source was in the pocket of a shirt. The worker was immediately tracked down and found to have a severe skin burn on his chest. And on his back, opposite the burn on the front of his body, was a patch of erythema. As Evans recounted the incident, “It got him right through the heart… those were the days of the wild west.”


  • Evans, R.D.; Mugele, R.A. Increased gamma-ray sensitivity of tube counters and the measurement of the thorium content of ordinary materials. Rev. Sci. Instr. 7:441-449; 1936.
  • Evans, R.D. Early history (1936-1946) of nuclear medicine in thyroid studies at Massachusetts General Hospital. Med. Phys. 2(3):105-109; 1975.
  • Evans, R.D. Origin of standards for internal emitters. In: Kathren and Ziemer’s Health Physics: A Backwards Glance. Pergamon Press; New York; 1980.
  • Evans, R.D. Acceptance of the Coolidge Award. Med. Phys. 11(5):579-581; 1984.
  • Gingrich, N. S.; Evans, R.D.; Edgerton, H.E. A direct-reading counting rate meter for random pulses. Rev. Sci. Instr. 7:450-456; 1936.
  • Hertz, S.; Roberts, A.; Evans, R.D. Radioactive iodine as an indicator in the study of thyroid physiology. Proc. Soc. Exp. Bio. Med. 38:510-513; 1938.
  • Kathren, R. Presentation of the 1994 Coolidge Award to Robley D. Evans. Med. Phys. 11(5):557-578; 1984.
  • Macklis, R.M. Radithor and the era of mild radium therapy. JAMA 264(5):614-618; 1990.
  • Peacock, W.C.; Evans, R.D.; Irvine, J.W.; Good, W.D.; Kip, A.F.; Weiss, S.; Gibson, J.G. The use of two radioactive isotopes of iron in tracer studies of erythrocytes. J. Clin. Invest. XXV (4):605-615;1946.
  • Seaborg, G.T. The positive power of radioisotopes. Sceptical Inquirer. Jan./Feb.:39; 1995.
  • Taylor, L. S.; Sauer, K.G. Vignettes of early radiation workers (Transcripts of the videotape series): Robley D. Evans. U.S. Dept. Of Health and Human Services; Rockville; 1984.

The kind assistance of Constantine Maletskos is gratefully acknowledged. Thanks also to Frank Massé for giving me the idea for this column.