The Human Plutonium Injection Experiments

days, respectively), these patients did

not receive the highest total doses.

Less than a month after the moribund

patient (HP-11) at Rochester had been

injected with 5 micrograms of plutoni-

um (on March 13), Langham had writ-

ten to Bassett, saying:

Your letter of February 27 regard-

ing Hp 11 was startling, to say the

least.  The specimens have already

arrived and I am making prepara-

tions to analyze them. . . . In case

you should decide to do another

terminal case, I suggest you use 50

micrograms instead of 5.  This

would permit the analysis of much

smaller samples and would make

my work considerably easier.  I

have just received word that

Chicago is performing two termi-

nal experiments using 95 micro-

grams each.  I feel reasonably cer-

tain there would be no harm in

using larger amounts of material if

you are sure the case is a terminal

one.

On March 27, Bassett replied, saying

that “this case did turn out to be termi-

nal, but at the time I started the experi-

mental period, there was sufficient un-

certainty regarding the outcome to

make me feel that the dose should be

within the range of tolerance.”  He

added that “if a suitable opportunity oc-

curred and if you are very anxious that

I should carry it through, I will see

what can be done [about a 50-micro-

gram dose in a terminal patient].”  The

opportunity never occurred.

The Chicago scientists also studied the

gastrointestinal absorption of plutonium

by having, on May 13, 1946, six male

employees of the Met Lab drink a

water solution containing 0.35

nanocuries (or about 6 nanograms) of

plutonium-239.  That amount was about

a factor of a thousand or ten-thousand

less than the amount injected into the

Chicago patients, so the plutonium ex-

creted in the urine and feces was barely

detectable.  Besides measuring the frac-

tion of the plutonium absorbed by the

gastrointestinal tract, the scientists used

the results to improve the interpretation

of plutonium exposure and bioassay

data collected from occupationally ex-

posed workers.

More California patients. On April

26, 1946, Hamilton and his group at the

University of California Hospital in 

San Francisco continued their studies,

injecting 2.7 micrograms of plutonium-

239 intravenously in a 4-year-old boy

suffering from terminal bone cancer

(CAL-2).  The injection solution also

contained radioactive cerium and yttri-

um.  A week later, surgery was per-

formed and significant bone and tissue

samples were taken.  The samples were

analyzed for the uptake of the radioiso-

topes and comparisons were made be-

tween normal and tumor tissue.  Thus,

the experiment may have been both a

continuation of Hamilton’s 1941 re-

search to find a therapeutic treatment

for bone cancer and a continuation of

the Manhattan Project plutonium me-

tabolism research—the data were ap-

plicable to both studies.

On July 18, 1947, a third person, a 36-

year-old man, purportedly with bone

cancer in the leg, was injected with a

mixture of plutonium-238 and tracer

amounts of other radioisotopes.  That

injection was done intramuscularly,

rather than intravenously, and after his

leg was amputated at mid-thigh, the de-

position of plutonium in the bone and

tissue was determined.  A month earli-

er, on June 10, a 16-year-old boy with

bone cancer had also received an intra-

muscular injection, but with americium

rather than plutonium.  Again, part of

the patient’s leg was amputated and tis-

sue samples were analyzed.  Both these

experiments may also have been a con-

tinuation of the bone-cancer research

and were possibly done independently

of the Manhattan Project or its succes-

sor, the Atomic Energy Commission

(AEC).

Such “dual-purpose” research produced

further data for the Manhattan Project

but also allowed physicians to search

for radioisotopes that could be used to

treat cancer.  The radioisotopes being

administered would not have any thera-

peutic value for the people receiving

the injections—the quantities were too

small—but the studies might have led

to the development of new therapies for

future patients.  

Results of the Injection

Experiments

By 1950, five years after the start of the

study, Langham and Bassett, as well as

Payne Harris and Robert Carter from

Los Alamos, wrote a classified report

(LA-1151) that summarized much of

what had been learned from the eleven

Rochester patients, the Oak Ridge pa-

tient, the three Chicago patients, and

the first California patient.  They con-

cluded that about two-thirds (66 per

cent) of the plutonium injected into the

bloodstream was deposited in the skele-

ton and more than a fifth (23 per cent)

was deposited in the liver.  Thus, “the

skeletal system and liver are the tissues

of major interest when considering the

plutonium tolerance, as these two or-

gans alone account for 90% or more of

the total plutonium in the entire body.”

The level of plutonium in the blood

was high at first (35.7 per cent of the

injected amount after 4 hours and 15.7

per cent after 1 day) but fell rapidly

(1.2 per cent after 10 days and 0.3 per

cent after 30 days), which ruled out the

use of blood tests “as a means of diag-

nosing the degree of exposure of per-

sonnel.” 

The Los Alamos report used the accu-

mulated data obtained from the fifteen

patients to determine excretion rate

equations, which appeared (for both

urinary and fecal excretion) to be most

easily described by “a logarithmic func-

tion:

Y

5

a X

2

b

,

The Human Plutonium Injection Experiments

210

Los Alamos Science Number 23  1995

continued from page 207

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