Terry Pratchet Terry Pratchett has raised the issue of using mercury in tooth fillings by blaming the cause of his early onset Alzheimer's condition on this practice and has described the use of mercury as "Toxic Waste".

He has been quoted as saying:

"Having something like mercury in your mouth seemed to me to be a really bad idea and I got rid of the stuff."

The Dental amalgam fillings, which are in millions of mouths in the UK, (over 3 million added last year) contain 50% mercury and campaigners including doctors have linked these fillings to MS, chronic fatigue syndrome and gut problems. There is at present no "hard" evidence for linking amalgam fillings to Alzheimer's however concern is growing with Sweden, Norway and Denmark all banning mercury containing products.

Peter Ward who is a member of the British Dental Association has commented that the safety of mercury fillings have been subjected to numerous reviews and none of these has found any risk of serious illnesses.

Mercury is a heavy, silvery metal and is one of six elements (and the only metal) in a natural liquid state at room temperature and pressure. Mercury is used in scientific measuring apparatus, like thermometers and barometers but conerns about the elements toxicity have led to these being largely phased out in clinical environments.

It is widely known that the soluble forms of mercury are very poisonous (mercuric chloride or methylmercury) and inhalation of mercury vapour or eating contaminated fish can prove fatal. It is however still classed as harmless in insoluble form (mercury sulfide etc). In the past Mercury has been used for a huge variety of uses, including Nuclear Reactor coolant, preserving wood, hat making and as a propellant in early Ion Engines.

Mercury has also been used in medicine, as far back as 1500 BC China and Tibet thought that mercury would prolong life, heal fractures and maintain generally good health.

One of China's emperors (Qín Sh? Huáng Dì) was allegedly buried in a tomb that contained rivers of flowing mercury on a model of the land he ruled, and died by dinking a mercury and powdered Jade mixture that caused liver failure, poisoning and Brain Death (This was intended to give him eternal life).

The ancient Greeks used it in ointments, the ancient Egyptians and Romans used it in cosmetics (It is still widely used in Mascara) and it was sometimes known to deform the face through its use!

Looking at Mercury's historical uses, it does appear to show that in just about every case, it has caused illness or Injury, and that given the Liquid form is known to be highly toxic, it does make you wonder why we allow this in our mouths.