Human Plutonium Injection Experiments

Nick Rolston
March 16, 2015

Submitted as coursework for PH241, Stanford University, Winter 2015

The Nuclear Golden Age

Fig. 1: Various oxidation states of plutonium in solution. (Source: Wikimedia Commons).

The Manhattan Project brought with it a sudden golden age of innovation and discovery in the area of nuclear weaponry research, producing the first atomic bombs during the Second World War. Over its five year period of activity from 1942-1946, the project controlled the U.S. research and development for nuclear bombs in the era leading up to the Cold War until the creation of the Atomic Energy Commission. Unfortunately, this exploratory phase of studying the properties and effects of nuclear elements involved a number of secretive experiments exposing humans to radioactive materials such as plutonium.

The First Experiments

In 1945, the first known injection of plutonium into a human occurred at Oak Ridge National Laboratory to a 55 year-old patient, referred to as HP-12, at the Manhattan Project Army Hospital. [1] He was said to be in general good health except for several sustained fractures from a recent automobile accident. After receiving an injection of 4.7 micrograms of plutonium in salt form, he was continuously monitored with regular urine and stool samples collected for over a month. [1] Several years later, a number of teeth were removed and analyzed for plutonium levels. HP-12 passed away in 1953 of heart failure, which was years before late radiation effects such as cancer were expected to develop. [1]

Analysis of Human Subjects, Injected 1945-1947

Table 1 shows a list of eighteen people who were injected with plutonium during the early years of experimentation. [1] The average age at the time of injection was 48.2 years, and the subjects lived for an average of 11.7 years after injection. The average age at death of about 60 years was significantly lower than the average life expectancy of birth at 1900 of 47.3. [2] However, it is not possible to assume that all patients were representative of adults in good health. For instance, the patients receiving the substantial dose of 94.2 mg of Pu-239 were both suffering from terminal illnesses at the time of injection, and their lifespans were not necessarily cut short from the radioactive effects of the Plutonium. Eleven of the eighteen individuals died less than ten years after exposure, which was before any long-term effects would likely have arisen. Eight of the patients survived for over a decade after injection, with six people living until their 70s and four reaching their 80s, which is especially long-lived considering most of these folks were born at the turn of the 19th century. Surprisingly, this analysis shows little support that any patients died for reasons directly resulting from the plutonium exposure. After all, ten patients succumbed to the disease or related complications for which they were initially treated.

Patient number and biographical information at time of injection Date injected Date of death Survival time Age at death Cause of death Weight of injected Pu-239 (mg)
HP-12, 55-year-old man 1945 1953 8 years 63 Heart failure 4.7
CHI-1, 68-year-old man 1945 1945 5 months 68 Cancer of chin, lungs 6.5
CAL-1, 58-year-old man 1945 1966 20.7 years 79 Heart disease 0.75 + 0.2 (Pu-238)
HP-1, 67-year-old man 1945 1960 14.2 years 81 Bronchopneumonia 4.6
HP-2, 48-year-old man 1945 1948 2.4 years 50 Brain disease 5.1
HP-3, 48-year-old woman 1945 1983 37.2 years 85 Acute cardiac arrest 4.9
HP-4, 18-year-old woman 1945 1947 1.4 years 20 Cushing's syndrome 4.9
HP-5, 56-year-old man 1945 1946 5 months 57 Bronchopneumonia 5.1
CHI-2, 56-year-old woman 1945 1946 17 days 56 Breast cancer 94.9
CHI-3, Young adult male 1945 1946 6 months Unknown Likely Hodgin's Disease 94.9
HP-6, 44-year-old man 1946 1984 38 years 82 Natural death 5.3
HP-7, 59-year-old woman 1946 1946 9 months 60 Pulmonary failure 6.3
HP-11, 69-year-old man 1946 1946 6 days 69 Bronchopneumonia 6.5
HP-8, 41-year-old woman 1946 1975 29.7 years 71 Unknown 6.5
HP-9, 64-year-old man 1946 1947 1.2 years 65 Bronchopneumonia 6.3
CAL-2, 4-year, 10-month old boy 1946 1947 8 months 5 Bone cancer 2.7 + radio-cerium and yttrium
HP-10, 52-year-old man 1946 1957 10.9 years 63 Heart disease 6.1
CAL-3, 36-year-old man 1947 1991 44 years 80 Respiratory failure .006 (Pu-238)
Table 1: Data from eighteen patients injected with plutonium between 1945 and 1947. [1]

Looking Back

Similar to many other controversial studies of the 1900s such as Milgram's shock-delivering obedience experiments, the Stanford prison experiment, and Jane Elliott's eye color prejudice experiment, a systematic study involving radioactive injections into humans would be immoral in today's scientific world. [3-5] Even worse, it is unclear if the people tested on for the experiments were ever informed or asked for consent. They almost certainly were not told that they were receiving plutonium dosages, as the word itself was considered a secret until the end of World War II, with classified documents referring to the element in code words such as "49" and "product". [6] A memorandum at the end of 1946 when authority was changing hands to the Atomic Energy Commission suggests that no consent was given in the experiments: "These doctors state that the injections would probably be made without the knowledge of the patient and that the physician's assistant assumed full responsibility. Such injections were not divergent from the normal experimental method in the hospital and the patient signed no release". [1] Secrecy and lying apparently became commonplace during the studies to keep a lid on it all. Yet instead of a conspiracy, denial was built and accepted by politicians and scientists alike who feared nuclear war. [7,8]

The Final Outcomes

In the aftermath of the various plutonium injection experiments, the legacy and impact of the knowledge from the studies is called into question. The systematic measurement of bodily fluids from patients in the days and years after the injections and the autopsy results gave significant data applicable to the calculation of time-dependent distribution of plutonium within the body. [1] The goal is to translate this data into biokinetic models, which are mathematical representations of the diffusion of elements and their radioisotopes in the body and their collection in various organs or tissues. [9] This would allow for the calculation of an effective dose from a known amount of plutonium exposure. The International Commission on Radiological Protection was able to generate information regarding an age-dependent dose based on intake, and thus formulated ingestion dose coefficients for the substance. [10]

© Nick Rolston. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] W. Moss and R. Eckhardt, "The Human Plutonium Injection Experiments," Los Alamos Science 23, 176 (1995).

[2] R. D. Grove and A. M Hetzel, "Vital Statistics Rates in the United States 1940-1960," U.S. Department of Health, Education, and Welfare, Public Health Service Publication No. 1677, 1968.

[3] S. Milgram, "Behavioral Study of Obedience," J. Abnorm. Soc. Psych. 67, 371 (1963).

[4] C. Haney, C. Banks, and P. Zimbardo, "Interpersonal Dynamics in a Simulated Prison," Int. J. Crim. Penol. 1, 69 (1973).

[6] W. Peters, A Class Divided: Then and Now (Yale U. Press, 1987).

[7] M. Sherry, "Human Guinea Pigs," New York Times, 12 Dec 99.

[8] E. Welsome, The Plutonium Files: America's Secret Medical Experiments in the Cold War (Delta, 2010).

[9] J. Harrison, "Biokinetic and Dosimetric Modelling in the Estimation of Radiation Risks from Internal Emitters," J. Radiol. Prot. 29, A81 (2009).

[10] "Age-dependent Doses to Members of the Public from Intake of Radionuclides: Part 2 Ingestion Dose Coefficients," International Commission on Radiological Protection, Publication 67, Ann. ICRP 23, Nos. 3-4 (1993).