@Grivusangel -- Steel towns smell bad, too. I remember Pittsburgh used to stink when the mills still ran. Pittsburgh took a similar route to Birmingham and fell back on its medical industry, with similar success. It's probably the only reason the city is still doing well.
The Pennsylvania mills closed largely for the same reason -- they didn't want to update their facilities. It was cheaper to move overseas, which they did.
I know there are smaller mills still operating, but they must be better about not spewing out pollution because I've been to towns that have working mills and I've never smelled them.