<P> As the Manhattan Project continued to use plutonium, airborne contamination began to be a major concern . Nose swipes were taken frequently of the workers, with numerous cases of moderate and high readings . 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 ." </P> <P> 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 . The first human plutonium injection experiments were approved in April 1945 for three tests: April 10 at the Manhattan Project Army Hospital in Oak Ridge, April 26 at Billings Hospital in Chicago, and May 14 at the University of California Hospital in San Francisco . Albert Stevens was the person selected in the California test and designated CAL - 1 in official documents . </P> <P> The plutonium experiments were not isolated events . During this time, cancer researchers were attempting to discover whether certain radioactive elements might be useful to treat cancer . Recent studies on radium, polonium, and uranium proved foundational to the study of Pu toxicity . For example, polonium (another alpha emitter) research indicated that test sample contamination was a major concern, which is why a clean room had to be established at Los Alamos in February 1945 in the Medical Labs Building . </P> <P> The mastermind behind this human experiment with plutonium was Dr. Joseph Gilbert Hamilton, a Manhattan Project doctor in charge of the human experiments in California . Hamilton had been experimenting on people (including himself) since the 1930s at Berkeley . He was working with other Manhattan Project doctors to perform toxicity studies on plutonium . It was Hamilton who had begun the 1944 tracer experiments on rats . The opportunity to select a human patient was relatively easy: Hamilton was not only a physicist assigned to U.C. Berkeley, he was "professor of experimental medicine and radiology" at U.C. San Francisco ." Hamilton eventually succumbed to the radiation that he explored for most of his adult life: he died of leukemia at the age of 49 . </P>

There was no radiation present prior to 1944