The current annual permitted dose for a radiation worker in the United States is 0.05 Sv (or 5 rem), i.e. an average of 5.7 μSv/h.

The Manhattan Project built mass scale production facilities for the war effort, specifically for the manufacture of nuclear weapons.

In August 1944, a chemist named Donald Mastick was sprayed in the face with liquid plutonium chloride, causing him to accidentally swallow some.

Unfortunately, this method has its limits in that only a small fraction of Pu is excreted, for example 0.01% of the body burden per day is typical, 2 to 3 weeks after exposure.

[2][7] While Dr. Robert Stone was the Health Director at the Met Lab in 1944, lead chemist Glenn Seaborg, discoverer of many transuranium elements including plutonium, urged him that a safety program be developed and suggested: "that a program to trace the course of plutonium in the body be initiated as soon as possible ... [with] the very highest priority.

"[8] Tracer experiments were begun in 1944 with rats and other animals with the knowledge of all of the Manhattan Project managers and health directors of the various sites.

In 1945, human tracer experiments began with the intent to determine how to properly analyze excretion samples to estimate body burden.

Numerous analytic methods were devised by the lead doctors at the Met Lab (Chicago), Los Alamos, Rochester, Oak Ridge, and Berkeley.

For example, polonium (another alpha emitter) research indicated that test sample contamination was a major concern, which is why a cleanroom had to be established at Los Alamos in February 1945 in the Medical Labs Building.

[1][2][8] As with all radiological testing during World War II, it would have been difficult to receive informed consent for Pu injection studies on civilians.

[10] The fact that he had the highly radioactive Pu-238 (produced in the 60-inch cyclotron at the Crocker Laboratory by deuteron bombardment of natural uranium)[10] contributed heavily to his long-term dose.

When specimens were taken during Stevens's cancer surgery, Earl Miller took them for radiological testing; Scott collected urine and stool samples.

There had also been no therapeutic intent for the experiment,[8][11] although surgeons assumed that Stevens had received radioactive phosphorus for "special studies".

"[1] Stevens's surgeons found a "huge, ulcerating, carcinomatous mass that had grown into his spleen and liver... Half of the left lobe of the liver, the entire spleen, most of the ninth rib, lymph nodes, part of the pancreas, and a portion of the omentum... were taken out"[1] to help prevent the spread of cancer that Stevens did not have.

The Manhattan District decided to pay for his urine and stool samples to keep him close to San Francisco on the pretext that his "cancer" surgery and remarkable recovery were being studied.

[8] Whenever Stevens had continued health problems, he would return to the University of California, San Francisco Medical Center (UCSF) and receive free gastro-intestinal lab work by Dr. Robert Stone, a radiologist who performed extensive human experiments in the 1940s.

His cremated remains were shipped to the Argonne National Laboratory Center for Human Radiobiology in 1975, but they were never returned to the chapel which held them from 1966 to 1975.

Some of the ashes were transferred to the National Human Radiobiology Tissue Repository at Washington State University,[1] which keeps the remains of people who died having radioisotopes in their body.

[13] Her work brought intense scrutiny on the wartime experiments which made Stevens famous, posthumously, for his contributions to science without informed consent.

Shortly after the article was published in November 1993, the Secretary of Energy, Hazel O'Leary, publicly stated that the government should compensate victims.

Responding to the issues revealed by Welsome, President Bill Clinton ordered the formation of the Advisory Committee on Human Radiation Experiments on January 15, 1994, to investigate.