[Symmetry]

There actually wasn't any appreciable fallout after the atomic bombs were dropped on Japan. Fallout is mostly generated when a bomb explodes close to the ground so that its neutrons are able to reach and transmute that ground into radioactive isotopes. The bombs dropped on Japan exploded high up to affect as large an area as possible. Many people suffered terribly from the ionizing radiation produced by those bombs, but all that damage was inflicted in the first microseconds immediately after the bombs detonated.

[MomsAVoxell]

Right, it was radioactive rain I am remembering someone describing to me when I was in Tokyo, discussing the subject. Not strictly fallout.

I remember there was some controversy over whether folks who were exposed to the black rain were eligible for health and medical support, and what constituted 'black rain' versus 'normal rain' and all the wide spectrum between ...