Roofers, on the other hand, have extremely high risk of severe injury and death. Those guys are nuts! If I was in charge of OSHA regulations for roofers I'd make sure that no one was allowed to get on to a roof without being attached to some kind of harness that would catch them if they fell. Or surround the home with airbags or something. It seems far too easy to slip, trip, or just plain ol' fall in that job.
I've personally witnessed a young man (roofer) fall from a roof once (on to a big pile of bricks). I found out later that he wound up paralyzed.
Electricians and plumbers are also relatively low risk depending on the work they do. You'd think working with high-voltage electricity would be higher risk than it is but with modern (insulated) tools and training it's quite safe.
Being an asshole has very little to do with crude language.
There's a pretty significant risk of DEATH (guys falling off from scaffolding, someone accidentally driving over you with an excavator etc.), you need to be on your toes a lot of the time or you'll hurt yourself, you work in heat, in cold, in dusty or moldy environments, in noise, with chemicals. On top of that, your boss is often an asshole (there's none of the white collar world politeness). Consider that construction work can pay pretty well even to people who hardly speak the country's language and have only moderate skills - I think it's largely because it's just shit.