HI there, I think it is hard to test for mercury levels because often mercury is hard to pick up. For example, you may have a hair test done and find barely any mercury level, yet you maybe very poisoned. Some people hang onto mercury tightly and do not tend to excrete it, so it may not show up.

Some of the sickest patients can show the lowest levels and this is called retention toxicity. either they are retaining mercury and not letting it go, and/or they are easily poisoned even by small amounts of mercury.

There are ways of testing that mercury maybe part of the problem by having a hair test done and checking mineral levels. Mercury tends to distort minerals in the body and there is often a pattern that can indicate mercury is at work. I do not know enough about that, but there is a book about that by Andrew Cutler.

Also some people do challenge tests, which means you take a loading dose of chelator (detox agent) to try and encourage the mercury in you to come out so it can be tested (urine). But again this is not always accurate and not always safe because it can make a person very ill from pulling out and moving mercury around.

Chelation is basically detoxing mercury or more accurately it means taking a chelation agent means taking something that has a strong affinity for mercury and will grab onto it. There are some agents that do not have a strong enough grip on mercury but can move it about. Other agents tend to hang onto it more strongly.

One filling may not sound much and may even seem unlikely to be bothering you, but I recall reading about a guy whose own tiny pit filling stood in the way of him having a happy and healthy life. He had previously been well, but after the filling he became sick and could no longer play sport. Once it was removed, he recovered.

So though it may not seem significant to have a small single filling, it's suprising how much even a small amount of ongoing mercury exposure can affect sensitive people.