The main problem is that there have been no major studies done to see the levels of toxicity in NORMAL healthy people's hair. So they can find you have a lot of one thing or another but in fact that's not really the problem - there has been no evidence to link levels of normal elements (base metals etc.) in hair to tendency to illness. If you have it done make SURE you have blood tests to make sure what is in your hair is IN FACT in your body too.

The body gets rid of it's many of its excesses through the liver, the kidneys and the lymphatic system - some of those toxins grow out in your hair - your hair shaft has no circulation so the chemicals your body puts there are not IN your system. Having high levels of something in your hair might just be a reflection of how well your body is managing to clear such things from the functioning systems.

In a situation where someone is being slowly poisoned this sort of thing can be useful, since it can reveal drugs which were in the system many weeks or months before, but even then it wouldn't be enough for court, only to get a warrant for further tests/searches. Cannabis is a drug which tends to grow out in hair and nails - your hair can be full of it but it's not IN your system anymore.

I think if you go into it with your eyes open it might help in a situation where you're ill and normal doctors are drawing a blank on why by narrowing down what you might want to look for in a normal blood screening.

Bx