The Legacy of Plutonium: 1940 to the Present
Colleagues:
I have been following with interest the exchanges on the role of testing in developing a knowledge base to inform the setting regulations and practices to control human exposures and limit potential human health effects. I have been pleased with much of the inform and disheartened by some of the mis-information. Much of the dialogue has been impacted by the "silos of science" that inhibit progress. Yes, much of chemical science is done by individuals well-trained and experienced in chemistry , however, with limited education and experience outside of that narrow world. The "silo of chemistry".. The same is true in many other scientific disciplines and fields. Professional organizations including the ACS promote the building and perpetuation of silos, it is self interest reigning. Unfortunately, this is a serious impediment in advancing knowledge and its application in many areas. The world of health protection is an excellent example. How many of the readers of this piece are members of other professional organizations concerned with health and safety issue, ie, AIHA, HPS, SRA, SOT , and others?
Let me now turn to the recent introduction of Plutonium in to the exchanges among DCHAS members.. I want to make certain the history of Plutonium and its health effects is correctly related. By way of background I should note my life and career have been heavily influenced by the discovery of Pu by Seaborg and his team in December 1940. They produced minute quantities of this new element in the 60 inch cyclotron at Berkeley. They soon discovered it was fissionable and might be used to fuel a new soon off and running. Startup of a small nuclear reactor at Oak Ridge in 1944 provided enough irradiated U fuel to separate out milligram quantities of Pu. Seaborg had the foresight to send an aliquot of this Pu to his friend , Joe Hamilton , a Berkeley. Hamilton and his colleagues injected it in rats. Yes, it went to the bone. However, it also went to the liver. Was this unique to rats? How about humans. They proceeded to inject humans and found it went the skeleton and liver.
In the fall of 1944 I joined my parents in Richland, WA where they had worked starting in 1943 with 40,000 others to build the Hanford reactors and separation facilities. I started the third grade , I was under age for radiation work. That would have to wait another decade.
Two individuals who would later become my mentors, Cantril (an MD experienced in using radiation to treat cancer) and Herbert M. Parker,{ a British trained radiological physicist)) set about writing a Radiation Protection Plan for Hanford workers. The Radiation Plan document, The "Tolerance Dose" was released in "Classified Form" on January 5, 1945. The Protection Plan Document guided Hanford work place practices even before it was formally released. The Hanford 100 B Reactor was started up in September 1944 and kg quantities of Pu were soon being produced and , in early 1945, shipped to Los Alamos to fuel the A-Bomb detonated at the Trinity site in July 1945 and over Nagasaki, Japan in August 1945. The Hiroshima Bomb was fueled by U. PU and U fueled weapons are very efficient , essentially all the Pu and U in the core is fissioned. Yes, Ralph is right TRACE quantities of Pu and U are dispersed.
The Radiation Protection Standards laid out by Cantrill and Parker in 1945 have proved to be highly effective. Post WW II a tremendous amount of additional research has been conducted on Pu, The Lovelace Inhalation Toxicology Research Institute, which I directed for 1966 to 1988 conducted number of life span studies in Beagle dogs with inhaled monodisperse particles of Pu-239 and Pu-238. Pu-238 has been used as a fuel for power sources in space. The primary results were an excess of cancers of the lungs, lung associated lymph nodes, skeleton and liver. I had the pleasure of hosting Glenn Seaborg on a visit ot our lab and compliment him on his fore sight in in anticipating the health effects of Pu. The "Beagle Dog Model" was inadvertently validated by the Russians in workers. The Russian Pu production facility at Mayak did not have adequate work place practices and controls. A long term study of the Mayak Workers yielded results similar to what I and my co-workers found in dogs.
In my opinion, the story of Pu and its health effects and the use of science to inform the development of standards and work place practices for Pu is a REMARABLE SUCCESS STORY. It reminds us of the need for a precautionary approach when dealing with newly discovered materials. Further, it provides an example of the multiple kinds of scientific information needed to inform the policy judgements that must be made in setting standards and work place practices and guiding the use of various agents.. An over arching guiding principle is to keep exposures as low as reasonably achievable (ALARA) . The use of radiation technology (nuclear medicine and nuclear reactors to generate electrical power) is a cornerstone of modern Society.
Respectfully,
Roger
Roger O McClellan, DVM, MMS, DSc (Honorary)
Diplomate, ABVT and ABT, Fellow- ABT, HPS, AAAR, SRA, AAAS
Member - National Academy of Medicine
www.rogermcclellan.com
