I brought this subject up in a previous post. And this is why I think that it is important not to fragment these categories too much. Many metal implants are made of titanium and other heavy metals and these too can cause problems similar to mercury toxicity. You see a whole slew of commercials on T.V about metal implant recalls and law suits associated with these. When are people going to learn that metal implants of any kind in any part of the body is not healthy?!!!!