To go off on a slight yet important tangent, Sweden has also banned mercury fillings! I noticed here

http://www.guardian.co.uk/lifeandstyle/2009/feb/15/mercury-fillings-alzheimers

that Mr Pratchett is linking his fillings with his alzheimer's.
I asked my dentist to remove mine but she refused, saying the BMA say they are safe, and besides, they're so toxic and removing them is such a dangerous proceedure that you're better off leaving them in your mouth(??).
After I had mine I became incredibly ill and developed a serious auto-immune disease in my stomach which has been linked to mercury poisoning.
I hope we follow Sweden some day. Hm, this could praps've done with its own thread, sorry!