HC Deb 28 January 1985 vol 72 cc55-6W
Mr. Lawrence

asked the Secretary of State for Social Services (1) if he will list the sources of any evidence available to his Department of the upper limit of consumption of fluoride before (a) the teeth begin to discolour through mottling and (b) harm to health may begin to result;

(2) if he will list the sources of any evidence available to his Department of the degree of mottling of children and young persons' teeth from water fluoridated naturally or artifically to one part per million;

(3) if he will list the sources of any evidence available to his Department of the effect of a high concentration of magnesium and calcium in water containing natural fluoride at levels at or above one part per million.

Mr. John Patten

The question of dental mottling was studied in the United States of America before the introduction of public water fluoridation. It was found that at a concentration of fluoride of about two parts per million an increasing proportion of children had mottled enamel that was apparent and objectionable aesthetically (Dean HT and Elvolve E "Further studies on the minimal threshold of chronic endemic dental fluorosis" — Pub Health Rep 52: 1249–64 10 September 1937).

There have been a number of studies contrasting the prevalence of dental mottling, which may have various causes, in comparable fluoridated and non-fluoridated areas. A review of the evidence is, for example, contained in pages 349–354 of Lord Jauncey's opinion in the Strathclyde fluoridation case.

Lord Jauncey concluded that if the drinking water in Strathclyde is fluoridated to one part per million there is likely to be a very small increase in the prevalence of mottling of a type which will only be noticeable at very close quarters and which is very unlikely to create any aesthetic problems for the owners of the teeth".

On the issue of harm to health, there is a substantial body of evidence which shows that levels of consumption associated with fluoride in drinking water considerably above the optimum level of one part per million are not associated with skeletal fluorosis in temperate countries. Published reviews of the evidence include the following:

Fluorides and Human Health (World Health Organisation, Geneva 1970).

Fluoride, Teeth and Health (a Report from the Royal College of Physicians of London, 1976).

Drinking Water and Health (National Academy of Sciences, Washington, 1977).

Victorian Water Supplies (Melbourne, 1980).

We know of no reputable evidence that a high concentration of magnesium and/or calcium makes any difference to the benefit to dental health obtained from drinking water containing natural fluoride at a concentration of around one part per million. Conversely the efficacy of fluoride has been demonstrated in this respect including areas where it has been artifically added to water with low concentrations of either magnesium and/or calcium.

Mr. Lawrence

asked the Secretary of State for Social Services what guidance he is proposing to issue of (a) toothpaste with fluoride, (b) fluoride tablets, (c) dentists applying topical fluoride and (d) users of kidney dialysis machines following the enactment of the Water (Fluoridation) Bill.

Mr. John Patten

No guidance will be needed on any of these issues. Topical fluoride may be safely applied in either fluoridated or non-fluoridated areas. We are currently issuing guidance to the Health Service on the exposure to aluminium and fluoride of patients undergoing haemodialysis. For the position with regard to fluoridated toothpaste and fluoride tablets, I refer my hon. Friend to my reply to him of 13 November 1984 at column217.