Chemical/Bio weapons used on Conus?

[Legbreaker]

My initial thoughts are that chem and bio weapons are most likely to have been used in the far north east, north west and south west of the country - basically where Soviet forces are to be found.
Elsewhere, chemicals would probably be limited to tear gas as police and various military units tried to break up riots, etc.
Of course there's always the possibilty of chem and bio contamination from accidents or production/storage facilities being damaged by a variety of causes (on the fringe of a nuke, mob riots, or perhaps a truck just overturning on an icy road).

Basically, just about anything can be justified if you think about it long enough.