NO one could be more convinced than I about the need to keep noxious chemicals out of our food and drinking water.

I would also, however, be the first to admit that before one such chemical was added to our water supply – in this case chlorine – people died in their millions of cholera, typhoid, hepatitis B and other water borne diseases.

It’s chlorine we have to thank for why this is no longer so (in the West at any rate). Chlorine, it should be noted, is not only poisonous, it’s also carcinogenic.

Fluorine is, of course, a chemical relative of chlorine and it too is highly poisonous.

Not necessarily so, though, as fluoride. The difference is subtle but crucial. Fluoride is an important trace-element, ie it’s essential to how your body works. It also stops tooth decay in children and Paget’s disease and Osteoporosis in adults (especially the elderly).

While I can sympathise to some extent with the unrestrained horror of certain correspondents from Darlington (HAS, Apr 10) at the prospect of having their drinking water “contaminated” with fluoride, I can assure them that their fears are groundless.

I might add by way of seemingly outrageous paradox that your body actually needs a certain amount of poison. That’s true of chlorine, arsenic, phosphorus and much else.

Tony Kelly, Crook