Be wary of any test that has a 90% or higher positive. For this reason alone the test must be questioned. I do not use the urine test for toxic elements, such as lead, cadmium, mercury and uranium, for this reason - every person gives a positive result - everyone in my experience, so the test has to be dodgy. Why subject a person to the cost of a test and ingesting a chemical when you are certain the result is already known?
A chemical chelating agent, such as DMSA, will inevitably cause a spike of toxic elements in one's urine levels. Every person is exposed to these toxins via their environment, including their food, and we are always excreting these, hopefully, as fast as they are being ingested. DMSA merely hastens the process of elimination for a short while. This test proves that we are all exposed to toxic elements; but it tells us zilch about whether there are deposits deep in the organs, fat and bones.
DMSA will only chelate out what is not locked in storage. It also depletes essential nutrients, so most chelation doctors will follow up chelation therapy with quite large doses of vitamins and minerals to replace those assumed to have been lost. It is a harsh therapy that leaves me unconvinced of it improving a person's long term health.
The testing lab I use endorses heavy metal chelation by gentle methods that support and enhance the body's natural processes for detoxification. I have been adhering to this philosophy and practice for many years. It is slow but works a treat. People get healthy as a result.
I was talking to a Dr friend of mine recently who was one of the first medical practitioners in New Zealand to do intravenous chelation therapy many years ago using chemicals like DMSA. It was a big part of his practice. People came from all around New Zealand seeking his therapies, including some of my family. I asked him how his chelation programme was going and he hesitated in his reply. He said that he was no longer offering it because he came to the conclusion, after many years, that people were not getting better, so he quietly canned the programme.
For more information about this topic, please read this and listen to the interview:
Dr Chris Shade on Mercury Toxicity and the mercury challenge test