Heather,
My son's holistic doctor tested him thru hair. He had no mercury in his hair samples, which she says indicate that his body does not process it normally, therefore, he could have mercury toxicity going on, as everyone is exposed to at least trace levels.
The mercury doesn't stay in the blood, I beleive they said it settles in tissues such as bone and brain. I should find out Wednesday what other methods are available for testing for it.
Just so you know, this gets into a real gray area in the medical community. difficult child's university doctor says the absence of mercury in his hair sample is a good thing; whilst a whole boat load of other docs (and parents of kids treated with chelation) say something completely different.
I was very skeptical about it, but have heard enough that I am at least learning a lot more about it. Jenny McCarthy's book "Mother Warriors" is full of stories from parents who's kids were substantially helped by chelation. I'll just say this, I've found enough evidence on my own to beleive that there could be something to it. I know my son's problems were not caused by vaccinations because we delayed them all due to a family history of allergies. That's not to say mercury and other strange results he had aren't compounding his problems, and I'm looking into it further.
I'll send you the book if you want it.
Research on your own. Your gp may say its bogus, but I encourage you to do your own research and make you own decision.