After the hazards of strontium-90 became evident, the next step was to focus on impact and damage per detonation. Smith's tests focused primarily on how many atomic weapons could potentially be detonated before radioactive contamination of air, water and soil became a long-term effect on crops, animals and humans worldwide. In 1949, Smith  estimated that it would take 3,000 Hiroshima-sized detonations in a single growing season to see if it have an effect on people who ate crops in affected areas. In 1951, Smith repeated this study with new information from the previous two detonations. With the new information, he then calculated that 10,000 Hiroshima-sized detonations would be needed before the long-term hazards became serious.
The testing was done with bones, urine and tissue samples collected worldwide. These samples were all tested for nuclear fallout, yet were falsely studied under the guise of nutritional importance and naturally occurring radon. It was determined that Sr-90 is a "bone-seeker," depositing in bones and marrow after ingestion. Civilian prisoners were considered for certain radiation testing, mainly Utah State prison inmates. One document revealed tests done on the bones of a stillborn baby showed that strontium-90 levels were 36% higher than the average 55% of other stillborn.