amalgam toxicity/amalgam intolerance.....how different?

this has bugged me for a while...

if u are sensetive to mercury then even a trace amount can harm u?
if u are poisoned by mercury but not sensetive to it then that indicates u have a large amount of mercury inside u, right?

if you are sentitive to mercury does it follow that the candida yeast would only need a trace amount of mercury to cause overgrowth within your body????

or is the sensitivity just based around your bodys reaction to the mercury, i.e nerveous system response,etc.

i feel i may have picked up the wrong end of the stick along the way!

thanks
james.