With everyone in my family (and my wife's family) being steel workers (and having worked in a zinc mill for 2 summers), I can tell you that the work absolutely was dangerous, dirty, loud, and hard.
On the other hand, each of my family believes that the hardest job was the underground coal miners in the same era. Thousands of feet underground, no electric lights, poison gases, mine collapses, cold, cramped, filthy, working with explosives, OSHA a future dream, and oh yeah, if you don't die on the job, you'll probably die of black lung in your 50's.