I first learnt about fluoride toxicity when I asked our dentist why the surface of my son's teeth looked blotchy. He made light of it. I don't remember if he at that timed gave it a name but I soon learnt that it was what he would call mild fluorosis. As I said he made light of it and even disregarded the unsightly appearance making a comment that it somehow made his teeth stronger against cavities. Yet my son developed a cavity on one of his front two teeth, a most unlikely place for a cavity. After learning about the dangers of too much fluoride we bought a distiller to take it out of our drinking water and have since switched to a Reveres Osmosis water system, but no system gets it all out.