I can remember when toothpaste tubes used to be made out of lead. I have never had lead poisoning (and yes, I brushed my teeth with toothpaste from them)nor have I ever heard of anyone getting sick from using them. MSM thrives on causing public paranoia. It sells advertising.
When I was very young, we used to play with little balls of mercury. If I suffered brain damage, I can only assume I would have been another Einstein.