Since it is well-known in the ag community that things like soybean rust spores can travel from the South to the Midwest via hurricanes....I don't think you are crazy at all.
When there is a major forest fire in the west; we get the "smog" and poor air alerts here in Iowa. Isn't it amazing how the small particles stay way "up there" for so long?
I agree. Many times you can tell if a Tstorm has put down a twister because the whole cloudbase turns dirt brown.