THE ADVENT of the atomic bomb as a military weapon has added a new group of constituents to the environment of man. These are the various radioactive fission products produced in the bomb explosion. In addition, the released neutrons serve to transmute a small quantity of atmospheric nitrogen to radiocarbon. By "local" fall-out is meant the deposition of fisson products in the area adjacent to the site of bomb detonation. Large quantities are also blown into the stratosphere, there to circulate for variable periods of time before returning to the earth as "distant" fall- out. Extensive studies by the Atomic Energy Commission and other governmental agencies (current expenditures for fall-out sampling exceed $12,000,000 yearly), as well as by foreign governments, have already provided a large body of observational data on fall-out and radiocarbon accumulation.
展开▼
