When you excrete metals through your urine, it is NOT showing you your body burden of metals, it's merely showing you what metals you are excreting, at that moment.
Heavy metals hide each other in layers and sometimes it's like peeling an onion. In other words, in my first 6 months of chelation I might be excreting lead and in month 7 I might all of a sudden start excreting mercury, when the lead is gone.
I thought I'd point this out because it's confusing to some people. Just because you aren't excreting mercury initially does not mean you aren't mercury toxic.