20 JUNE 1958, Page 19

FLUORIDATION

SIR,—My letter of May 16 expressed the view that the assessment of the safety of fluoride was a matter for experts. 1 had hoped we might avoid a corre- spondence in which isolated facts were taken out of their context with inevitably misleading impressions. Mrs. Grant, for example, states that fluoride is RAT POISON—the inference being that human beings drinking water to which fluoride has been artificially added will be poisoned. But it should be perfectly well known to Mrs. Grant that the amount of fluoride necessary to produce any such effect would need to be vastly greater than could possibly be consumed in fluoridated water by any one individual.

I do not propose to deal with all the misleading statements in Mrs. Grant's letter, but others may wish to do so. I would add, however, that the precise chemical description of the fluoride present in fluoridated water is fluoride ion—no matter whether sodium or calcium fluoride is used. Calcium and sodium are both always present in any water.—Yours Editor

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