The following paragraph by Michele Gerber, the official historian at Hanford, the huge plutonium production site in Washington State, is excess to my requirements, but I like it for its concise exposition of something important. The advent of reactors and bombs during World War II led to not only a vastly greater quantity of artificial radiation, the types and varieties of radiation also scaled up dramatically.
The Met Lab scientists themselves were products of the prewar era. They expressed everything in terms of X-ray and radium “equivalents,” because the world had had no experience with the array of fission products generated in an atomic reactor or in the chemical separations processes that refined and concentrated plutonium. Despite the intense research efforts of the MED and the Met Lab, a dizzying amount about the biochemical hazards and effects of radioactivity simply was not understood in the World War II era. The scientists realized this themselves, as a 1947 DuPont report confirmed: “At the time the [Hanford] Project began, there was no established tolerance limits for certain of the hazards which would be encountered … Product hazards were not completely understood.” They had an overall, but not a specific, knowledge of danger.
Gerber, Michele S. 2002. On the Home Front: The Cold War Legacy of the Hanford Nuclear Site. University of Nebraska Press, Lincoln, p. 29.