I was there last maybe ten years ago, it was not bad at all. You could still see the soot on old bridges though.
Yeah, the traditional steel towns were filthy back in the day. I remember the Gary, IN steel mills and Chicago stockyards from the 40’s and 50’s, I lived right in the cross hairs of both of them. They needed to be fixed and they were. My beef is with today’s “environmentalists” whining pukes who have no clue what bad air was like!