How Deadly is Plutonium?

Rarely is the word “plutonium” published in a major news source without the adjective “deadly” nearby. Ralph Nader, noted activist and lawyer, once claimed that plutonium was “the most toxic substance known to mankind.”

Hundreds of millions of dollars are being spent each year in the United States doing studies of the characteristics of a site for long term geologic storage of spent nuclear fuel. Much of the money is aimed at ensuring that no material ever gets out of the storage area. The material that seems to cause the most concern is the small amount of plutonium found in the irradiated fuel assemblies.

Some pundits have suggested that plutonium, even in quantities far too small for a nuclear weapon, could be used as a terrorist weapon to poison water supplies. It is said that such a use could cause thousands of deaths.

Exposure by Ingestion

Other writers and scientists, often with far less publicity, have published detailed analyses of these claims and used statistics and experience to prove them totally false. One man, Dr. Bernard Cohen, went so far as to volunteer to eat as much plutonium as Ralph Nader would caffeine in an attempt to demonstrate the folly of the severe toxicity claims.

Mr. Nader refused the challenge. Many anti-nuclear groups now try to claim that Dr. Cohen is an unreliable source of information since he volunteered to expose himself to such a dangerous substance.

Dr. Cohen, a tenured research professor at the University of Pittsburgh, stated that he had calculated his risk from the challenge as less than that of a typical draftee during World War II. Dr. Cohen feels that wise use of nuclear energy is as important as winning the war. He wanted to do his part in the battle to achieve public acceptance of the low level risk involved.

An indication of the risk one would face from ingesting small amounts of plutonium, of the amounts postulated for accident scenarios at an operating plant (or fuel storage facility) is shown by the following story.

Accidental Ingestion Studied

During the Manhattan Project in 1944 and 1945, 26 men accidentally ingested plutonium in quantities that far exceeded what is now considered to be a lethal dose. Since there has been a consistent interest in the health effects of this brand new substance (first discovered by Glenn Seaborg’s team at the University of California in 1940), these men were closely tracked for medical studies.

Forty Years Later

As of 1987, more than four decades later, only four of the workers had died and only one death was caused by cancer. The expected number of deaths in a random sample of men the age of those in the group is 10. The expected number of deaths from cancer in a similar group is between two and three.

The sample size is quite small; even during a crash wartime program, people normally handle plutonium with extreme care. Even people who work directly with the material in a manufacturing process that involves grinding and shaping can be adequately protected.

It is, of course, possible that the differences between expected deaths and actual deaths is just a statistical aberration. With small sample sizes, it is likely that large variations in mortality rate will be seen.

It has to be considered important, however, to know that at least 22 men have been able to live more than 40 years after ingesting “the most toxic substance known to man.” It should make one question the motives and accuracy of Ralph Nader, a public figure who has actively promoted such an obviously inaccurate statement.

One final thought. Glen Seaborg, Nobel Laurate, discoverer of plutonium, a man who spent much of his professional life determining its chemical properties, has recently been selected the honorary chair of the American Nuclear Society Special Panel on the Protection and Management of Plutonium. Dr. Seaborg is 83 years old and he still maintains an active schedule of committees and speaking.

Update: (Posted at 1250 on April 1, 2011) Wow, I wrote that post a long time ago, but recent events and news reports have made it the most visited post for the first week of the newly redesigned Atomic Insights web site. If you would like some additional information about the health effects of plutonium because you have read about it being found in the soil near the heavily damaged Fukushima Daiichi nuclear power stations, you might want to visit the following fact sheet that was produced in 2005 by the Argonne National Laboratory.

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4 Responses to “How Deadly is Plutonium?”

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  1. Matt J. says:

    Ralph Nader’s catchy phrase has become very well known. The counterexample you give should be enough to disprove it, but I have to wonder about the circumstances: how on earth did it happen that they accidentally ingested it anyway? Did it get on their food? Did something in the food inhibit absorption? Perhaps that is what saved them.

    Without further details, it is impossible to know these details, and so impossible to evaluate its real meaning.

    • Rod Adams says:

      Matt – the workers were bomb manufacturers. Most of the exposures came as a result of industrial events like glove bag failures. When you are grinding pieces to form the lenses of a device and the glove bag fails, you end up breathing some dust.

  2. Rick Maltese says:

    Alvin Weinberg, Edward Teller, Eugene Wigner, Ralph Moir, Glenn Seabourg, Charles Barton Senior, ____? Parker lived long lives plus a few more I’m sure I missed all provide evidence that hormesis is an explanation for their longevity. Maybe you can add to this list. I’d say it’s pretty compelling.

  3. Rick Maltese says:

    Hi Rod

    Congratulations on the new system. Looks good.
    Not sure you are aware but comments are closed on a few of your most recent posts. Thought you might want to know in case it was unintentional.