The letter headed "Scaremongering about fluoride" (April 20), commenting on your earlier article about fluoridation, was very confusing as it seems to have been combined from two separate correspondents, with very different views.

Readers should know that the first part, describing how "researchers analysed the trace elements in long-term studies", was in my opinion incorrect.

Fluoride on its own does not occur naturally. "Natural" calcium fluoride would be much too expensive to use.

In fact, the form of fluoride used to dose water is most usually hydro- (or hexa-) fluorosilisic acid, a highly toxic and contaminated waste product of the phosphate fertiliser industry.

The idea of fluoridating public water supplies originated in the US, where it has been promoted over time by industrial interests as a way of disposing of a dangerous by-product. Fluoridation has never been scientifically proven to help teeth and actually damages them.

Putting it in our water supply is completely unethical, contravenes European human rights conventions and is unwanted in Sussex.

-Ivor Hueting, Eastbourne