[2] The Los Angeles Times, August 19, 1994, Editorial, "The NewThreat That Must Unite the World": "A highly radioactive element that did notso much as exist before nuclear technology first produced it in the 1940s,plutonium is one of the most toxic substances known to science. Oneten-thousandth of a gram, inhaled, can cause cancer. A few ounces in an urbanwater reservoir could cause hundreds of thousands of deaths. And plutonium-239,an isotope of the element, is a key ingredient in nuclear bombs."

[3] The Herald (Glasgow, Scotland), August 19, 1994:"Plutonium-239 is so toxic that one-millionth of a gram can kill, and expertshave said that the 10 oz seized at Munich airport last week would have beenenough to contaminate all Germany's drinking water."

[4] Plutonium oxide is a solid under ordinary circumstances. It doesnot readily vaporize (it is less likely to vaporize, for example, than ordinarysilica [quartz] beach sand); it melts at a temperature higher than quartz; andit is much less soluble in water than quartz. See R. H. Condit,Plutonium: An Introduction, Lawrence Livermore National Laboratory,Livermore, CA, UCRL-JC-115357 (1993).

[5] W. J. Bair, "Toxicology of Plutonium," in Advances inRadiation Biology, J. T. Lett, H. Adler, and M. Zelle, Eds. (AcademicPress, New York, NY, 1974), pp. 255-315.

[6] D. S. Myers, The Biological Hazard and Measurement ofPlutonium, Lawrence Livermore National Laboratory, Livermore, CA,UCRL-76571 (1975). An estimate of the acute toxic effect of plutonium is basedon a calculation of the radiation dose it would deliver to the lining of the GItract. A lethal dose of 0.5 grams appears plausible, but the actual amountwould depend on a variety of circumstances.

[7] C. J. Lambertsen, "Noxious Gases and Vapors, Carbon Monoxide,Cyanides, Methemoglobin, and Sulfhemoglobin," in Drill's Pharmacology inMedicine, J. R. DiPalma, Ed. (McGraw-Hill Book Co., San Francisco, CA,1971) 4th ed., pp. 1189-1194.

[8] Studies of dogs exposed to high levels of plutonium show thatdeath from pulmonary edema could be expected to occur from 1 to 10 days afterintake in those dogs whose initial alveolar deposition was in the range of 10to 1 microcuries of plutonium. Such an intake is comparable to a human inhalingabout 100 milligrams of weapons-grade plutonium. Inhaled quantitiessignificantly less than this (e.g., 20 milligrams) might not cause death fromedema, but would be expected to cause death within roughly a month frompulmonary fibrosis; see W. J. Bair et al., "Plutonium in Soft Tissues withEmphasis on the Respiratory Tract," in Uranium, Plutonium, TransplutonicElements (Springer-Verlag, New York, NY, 1973).

[9] Throughout the balance of this paper, the word "dose" is used asan abbreviation for the more technically correct term "committed effective doseequivalent"--that is, the total effective dose equivalent that the person iscommitted to receive as the result of an intake of radioactive materials,during the 50-year period after the intake occurs. The total effective doseequivalent defined in Limits for the Intake of Radionuclides by Workers,International Commission on Radiological Protection (ICRP) Publication 30(Pergamon Press, Cambridge, UK, 1979), is a weighted sum of organ doseequivalents multiplied by appropriate risk weighting factors.

[10] These values are based on effects observed at relatively highexposures. The usual (and conservative) assumption is that the risk of gettingcancer at lower exposures is linearly related to the exposure. This risk wouldbe in addition to the natural incidence rate of fatal cancer, which isapproximately 20% for the United States population. Thus, if an individualinhaled 0.0008 milligrams of plutonium, that individual's risk of developingfatal cancer as a result of this exposure would be increased from 20% to 21%.If each of 10 individuals inhaled 0.0008 milligrams of plutonium, theprobability that one of them would get cancer would be 10%, since eachindividual has a 1% risk. That is, the probability of a cancer appearing in anexposed population depends simply on the amount of plutonium collectivelyinhaled. For each 0.08 milligrams of plutonium inhaled by the exposedpopulation (regardless of the size of the population), one additional fatalcancer would be expected to occur.

[11] As noted previously, 0.5 grams is the estimated quantitynecessary to deliver an acutely lethal dose via ingestion. It is also,coincidentally, the estimated quantity of ingested plutonium required toproduce a fatal cancer. Thus, 0.5 grams administered acutely to a singleindividual would be an acutely lethal dose. If the 0.5 grams were administeredchronically to a single individual or distributed among multiple individuals,it would be expected to result in an additional case of fatal cancer.

[12] B. L. Cohen, "Catalog of Risks Extended and Updated,"Health Physics 61 (3), 332 (1991).

[13] The probability of cancer arising from inhaling one particle ofthe largest respirable size is about one in 17 thousand, or 0.007%, ascalculated in the preceding paragraph.

[14] V. Kogan and P.  M. Schumacher, Final Report onRecommended Plutonium Release Fractions from Postulated Fires, EG&GRocky Flats, Inc., Rocky Flats Plant, Published by Battelle, 505 King Avenue,Columbus, Ohio 43201, December 1993.

[15] D. R. Stephens, Source Terms for Plutonium Aerosolizationfrom Nuclear Weapons Accidents, Lawrence Livermore National Laboratory,Livermore, CA, UCRL-ID-119303 (DRAFT), (to be published).

[16] U.S. Nuclear Regulatory Commission, Reactor Safety Study, AnAssessment of the Accident Risks in U.S. Commercial Nuclear Power Plants,WASH-1400 (NUREG-75/014), Washington, DC, Table VI B-1 (1975). C. E. Lapple,"Characteristics of Particles and Particle Dispersoids," Stanford ResearchInstitute Journal, Third Quarter (SRI, Menlo Park, California, 1961). Alsoavailable in CRC Handbook of Chemistry and Physics, 61st Edition (CRCPress, Inc. Boca Raton, Florida, 1980-1981), p. F-285.

[17] Steve Fetter and Frank von Hippel, "The Hazard from PlutoniumDispersal by Nuclear-Warhead Accidents," Science & Global Security2 (1), 21-41 (1990).

[18] For example, see Thomas J. Sullivan, James S. Ellis, Connee S.Foster, Kevin T. Foster, Ronald L. Baskett, John S. Nasstrom, and Walter W.Schalk III, "Atmospheric Release Advisory Capability: Real-Time Monitoring ofAirborne Hazardous Materials," Bull. Am. Met. Soc. 74 (12), 2343(1993), and Airborne Release Fractions/Rates for Non-Reactor NuclearFacilities, U.S. Department of Energy, Washington, DC, DOE-HDBK-3010-YR(October 1994).

[19] R. H. Condit, Plutonium Dispersal in Fires, a Review ofWhat Was Known as of 1986, Lawrence Livermore National Laboratory,Livermore, CA, UCRL-ID-114164 (1993).

[20] R. E. Luna, A New Analysis of the Vixen A Trials,Sandia National Laboratory, Albuquerque, NM, SAND93-2628, TTC1285 (1994).

[21] J. Newell Stannard, Radioactivity and Health, a History,Pacific Northwest Laboratory, Battelle Memorial Institute,DOE/RL/01830-T59(DE88013791), pp. 1191-1207 (1988), and references onpp. 1243-1251.

[22] W. M. Place, F. C. Cobb, and C. G. Defferding,Palomares Summary Report, Field Command, Defense Nuclear Agency,Technology and Analysis Directorate, Kirtland Air Force Base, NM (1975).

[23] B. Allard and J. Rydberg, "Behavior of Plutonium in NaturalWaters," in Plutonium Chemistry, W. T. Carnall and G. R. Choppin, Eds.(American Chemical Society, Washington, DC, 1983), pp. 275-295.

[24] In fact, if all 283,000 milligrams were ingested(which representstwo extremely implausible events), one would expect 283000 x 0.0021 =590 cancers--still very far from "hundreds of thousands."

[25] V. E. Noshkin, A. C. Stoker, K. M. Wong,J. L. Brunk, C. L. Conrado, H. E. Jones, S. Kehl, M. L.Stuart, L. M. Wasley, R. V. Bradsher, and W. L. Robison,Transuranic Radionuclides Dispersed into the Aquatic Environment, aBibliography, Lawrence Livermore National Laboratory, Livermore, CA,UCRL-ID-116541 (1994).

[26] International Commission on Radiological Protection,Recommendations of the International Commission on Radiological Protection,ICRP Publication 60 (Pergamon Press, Oxford, UK, 1991).

[27] Exposure of the Population in the United States and Canadafrom Background Radiation, National Commission on Radiation Protection,NCRP Report 94 (1987).

[28] P. M. Dove and J. D. Rimstadt, "Silica-WaterInteractions," in Silica: Physical Behavior, Geochemistry and MaterialsApplications, P. J. Heaney, C. T. Prewitt, and G. V. Gibbs,Eds. (Mineralogical Society of America, 1994; Reviews in Mineralogy,Vol. 29), pp. 257-308.

[29] Replenishment of the reservoir with uncontaminated water wouldreduce the concentration of plutonium, making the lifetime dose to anindividual less than estimated here.

[30] W. R. Penrose, W. L. Polzer, E. H. Essington,D. M. Nelson, and K. A. Orlandini, "Mobility of Plutonium andAmericium Through a Shallow Aquifer in a Semiarid Region," EnvironmentalScience and Technology 24, 228-234 (1990).

and LLNL Disclaimers

UCRL-JC-118825