The best way to test is with a hair analysis. The problem is that it
has to properly interpreted because if you're in stage 1 or 2, mercury
will show up low even though you could have mercury toxicity.

Finding a doctor that knows how to interpret these tests is hard. I
really should locate one for people so I can refer people to him/her
because I get asked this question so much.

I'll see what I can do in locating someone and post the info here if I
am successful. Otherwise, if mercury comes back low on the hair
analysis, it will have to be interpreted using a resource like the book
I suggested:

http://herballure.com/vp/hti

Sorry it isn't simplier.