This is why you can get symptoms of mercury toxicity from breathing in your own vapors (when it offgasses out of your pores).

I used to get it when it came off my skin, when I bathed or exercised. As crazy as this sounds and it will sound crazy, I would get wheezing in my lungs and uncontrollable giggling fits, as though I had been expoed to some gas.

A similar thing used to occur when I had amalgams and drank any hot fluids. Basically because the heat increased the vapor from the fillings and I would breath it in.

By the way, some forms of magnesium can act as a mild chelating agent with mercury. Might be why you notice this smell more when you're taking it!

If the mercury is coming out of your pores, that is one of the best ways and I would encourage it if yu can, without overdoing it or making yourself ill.