REPORTS IODINE-131 FALLOUT FROM UNDERGROUND TESTS.

Evidence that the fallout of iodine-131 in the Midwest during May 1962 originated in Nevada is provided by data on air trajectories, radioactivity in milk, and other findings. Selective escape of radioiodine from vented explosions, and the rapid transfer of iodine from the lower atmosphere to the biosphere, place, significance on even minor releases of radioactive fission products from subsurface nuclear explosions.