Health Risks of Plutonium Part II

I’ve received comments about what I’ve written on risks from low levels of plutonium in the environment and that I would be comfortable visiting the wildlife refuge at the former Rocky Flats site with my family. One worrisome assertion was that plutonium “was designed to kill.” Plutonium was generated in large quantities in a natural underground “reactor” in Africa that was dubbed the “Oklo Phenomenon a bit under two billion years ago. I agree that plutonium and other elements (i.e., arsenic) are toxic at some exposure level, but I can’t think that Mother Nature designed them to kill.

Another commenter referred to “Mortality Among Plutonium and Other Radiation Workers at a Plutonium Weapons Facility” by Gregg S. Wilkinson, et al. (The copyrighted article is online in the February 1987 edition of the American Journal of Epidemiology.) The responder points out Rocky Flats workers with higher levels of occupational plutonium exposure had a somewhat higher incidence of a few types of cancers than were experienced by the general population. My primary focus was on the abstract of the report that says, “Mortality among 5413 white males who were employed at least two years…(at Rocky Flats) was investigated to measure risks from exposures to low levels of plutonium and external radiation. When compared with US death rates, fewer deaths than expected were found for all causes of death (and) all cancers…”  That remarkable result was reached despite the fact that 26 percent of the workers had body burdens of plutonium from occupational exposure.

I don’t read the report to be a basis for some of the dire warnings being issued about the risks to people who chose to spend a few hours visiting the refuge, since the average person working in the industrial area for at least two years was not at increased risk.  In fact, people visiting the area west of the former industrial area will be exposed to about the same amounts of plutonium as is in their back yards from worldwide fallout. Anyone wanting to minimize their exposure to plutonium should avoid mountains where snow washed out higher levels of fallout.

I will post dissenting comments if they are civil, to the point, and factual. Other than that, I intend to move on to subjects that are more enjoyable.

Health Risks of Plutonium

The people I worked with at Rocky Flats were experts on handling radioactive materials and limiting exposures and managing risks associated with plutonium and other radioactive and potentially hazardous materials. They were committed to controlling emissions to the lowest possible levels since, after all, many lived with their families close to (even downwind of) the Plant. However, an issue that continues to receive attention is the health risks of low-level plutonium emissions that occurred during the nearly 60 year operations and cleanup of the RF site.  opposes a proposed beltway that is proposed to be constructed near the Rocky Flats site, and mentions concerns about plutonium contamination.

In an exchange with a commentator, I used the comparative term “very little” to describe an average of 0.006 ounces plutonium per year emitted from routine operations that processed tons of the material at the RFPlant. This is equivalent to 0.2 ppm emission (99.999% capture) for a processing rate of one ton per year.  The commentator responded that “very little” was inappropriate, since his research found “billions of particles per acre.”

This “billions per acre” seems an impressive number until put it in context with concentrations of radioactive elements — and plutonium, in particular — from worldwide fallout (discussed in chapter 25 of the book on this site). The book, “Transuranic Elements in the Environment,” indicates measured fallout levels of plutonium per square kilometer in northern hemisphere soils ranged from 0.1 to 2.2 millicuries (mCi = 0.001 Ci). This is equivalent to some 10 to 300 million billion (i.e., quadrillion) atoms per acre from fallout alone, which is not connected with RFP operations. Epidemiological risk calculations suggested that exposure to fallout plutonium could result in up to 125 to 600 additional cancer deaths (of the US total 500,000 per year), but researchers could not preclude the possibility that no additional cancer deaths would result.

The health risk from radioactive materials like plutonium is an unresolved issue. I’ve posted a review of the book “No Place to Hide,” that discusses the continuing health risks created by historical atmospheric nuclear testing.

Video of Nuclear Detonations 1945-1998

This post provides a link to the subject video that is a haunting presentation prepared by Isao Hashimoto of the 2053 detonations in the 53 year time frame.  I also put the link in the book about Rocky Flats, but want to make it available to as wide an audience as possible.  The United States conducted 1032 of the total detonations.  The first was Trinity and the next two were over Hiroshima and Nagasaki.  It takes about 15 minutes to watch, but I recommend it.