If they're breathing in toxic mercury everyday, then it's no surprise that a few would suffer mental symptoms and one of them is suicidal thoughts and many people who have mercury poisoning are afflicted with such thoughts and some even go through with it. It's a sad thing, but that's what this toxin can do. Dr Hal Huggins talks about it.

And a higher amount of birth/reproductive problems in dental assistants too and dental nurses apparently. Which is why, by law, in some areas it is required for a sign to be put up warning against the effects of mercury on pregnancies (and I think reproductive effects).

I would never work around mercury. I can't even walk into an office without becoming more poisoned.