Fluoridation: Aspects of toxicity

[Malcolm Harris, Ph.D. (Wales), B.Pharm (Wales), FPS, Fss, FRSH]

Fluoridation: Errors and Omissions in Experimental Trials

[Chapters 19, 20 and 21. Philip Sutton. Originally published in 1960]

The Kinetics of Acetylcholinest'se Inhibition and the Influence of Fluoride and Fluoride Complexes on the Permeability of Erythrocyte Membranes

[Westendorf, 1975]

Fluoridation: Aspects of toxicity

by MALCOLM HARRIS Ph.D. (Wales), B.Pharm. (Wales), FPS, FSS, FRSH.

Originally printed in The Probe (October 1976)

FOR the purposes of the Pharmacy and Poisons Act, 1933, a poison (including the ingredients of many dispensed medicines) is defined simply as any substance in the Poisons List issued by the Home Secretary.

The Poisons List is divided into two parts. A Part I poison may be sold or supplied to the public fly by an authorised seller of poisons, i.e., a pharmacist in general practice, while a Part II poison may be sold by either a pharmacist or a "listed seller of poisons" such as a registered seed merchant.

At the moment the poisons regulations are in a state of transition. Within a few months the 1933 Act is to be repealed. Poisons which are medicinal products will then come under the new Medicines Act, 1968, and non-medicinal poisons will come under the new Poisons Act, 1972.

Calcium fluoride (caF2), which occurs naturally, is not included in the Poisons List. This is because natural fluoride is not very soluble in water. Substances used in the artificial fluoridation of the public water supply are *sodium fluoride (NaF), sodium fluorosilicate (Na2SiF6), and hydrofluosilicic acid (H2SiF6). These artificial fluorides are highly soluble in water (References 1 and 2) see Table 1, and are highly toxic substances.

*NB. Sodium fluoride is no longer used in the UK.

Table 1.

They are used primarily as insecticides and rodenticides, usually made up as commercial preparations sold for this purpose. The raw materials are Part II poisons, but Schedule 3 of the current Poisons List exempts alkali fluoride preparations when sold as the following: wood preservatives, dentrifrices, mouth-washes, and tablets for tooth decay, each with a specified maximum fluoride concentration in the commercial product.

Sodium fluoride is put into the public water supply at 2.2mg per litre to give a concentration of 1 mg per litre of fluoride ion. In Britain this gives a daily intake of about 1.5 to 2.0mg of fluoride ion, and about 3.0 to 5.0mg of fluoride ion during a hot

summer because of the higher fluid intake. Some states in America reduce the fluoride ion concentration in their water to 0.5 to 0.7mg per litre at a prevailing air temperature of 70°F, yet in this country we have been experiencing 80° to 90°F air temperatures for a long period, with no reduction in fluoride concentration. Flexibility is not allowed by the Department of Health and Social Security in Britain      because of the temperate climate! Any reduction in fluoride concentration would be tantamount to admitting that some degree of toxicity exists.

We also take in fluoride from other sources, namely food, alcoholic and soft drinks, the air we breathe (from factory emissions), cosmetics and toothpastes containing fluoride, and certain pharmaceutical preparations.

Estimates of the fluoride intake from food alone vary from 0.5 to 2.0mg daily, and suggest a further 4.0mg from about seven cups of tea. Many of the estimates are out of date and unreliable because they do not take account of food made or prepared with fluoridated water.

Boiling a kettle or saucepan can concentrate artificial fluoride in the water from 1ppm to between 2 and 10ppm, and fur on the element of an  electric kettle can provide more.

A Royal College of Physicians report (Reference 3) indicates that "where there is little fluoride in the water the average daily intake by adults is less than 3.0mg with a maximum of less than 8.0mg, while with 1mg per litre (of fluoride) in water, the average daily intake is less than 5.0mg with a maximum of about 12mg."

Fluorophiles say that if we get so much fluoride from our food and tea anyhow, then the 1.5 to 5mg per day extra from drinking water is safe. Fluorophobes argue that since we get so much fluoride, is there really a need to add more to our body burden?

A more important question which can be answered with less ambiguity is whether there is any difference between natural and artificial fluoride? Calcium fluoride is the most frequently occurring natural fluoride, and sodium fluoride is representative of the artificial fluorides. Since the molecules of natural and artificial fluoride compounds ionise almost completely in water, the fluoride ion will be the same in each instance:

CaF2 = Ca++ + 2F-

NaF = Na+ + F-

However, the difference between these two compounds, and between natural and artificial fluorides in general, is essentially a matter of solubility which is a vital aspect of toxicity.

The Royal College of Physicians report (Reference 3) quotes that concentrations of natural fluoride ion in water "may be as high as 16mg per litre in the US and even 95mg per litre in Africa". Later in the report, under the heading Skeletal Fluorosis, there is a statement that "severe cases result from the continuous exposure of 20 to 80mg of fluoride daily for 10 to 20 years, associated with levels in the water of l0mg per litre." There appears to be something wrong in these statements.

The elements Ca and F are combined to form the compound CaF (molecular wt. 78.08) see Table 2. Since the maximum solubility of CaF in pure water is 16mg per litre at 18°C and 17mg per litre at 26°C, these give maximum concentrations of fluoride ion as follows:

(19 + 19) x 16 = 7.8mg per litre at 18°C

   78.08

(19 + 19) x 17 = 8.3mg per litre at 26°C

   78.08

Table 2.

The majority of fluoride-containing minerals are only sparingly soluble in water, and the rock of which they form a constituent is even less soluble. As the natural CaF2 is derived from the rock-forming mineral fluorspar or fluorite, the solubility will depend upon the acidity and leaching power of the water on the rock. This means that the natural fluoride ion concentration of most waters cannot much exceed 8.0mg per litre, unless other ions are present in the water capable of associating with the hydrated Ca ions, and thereby increasing solubility of the fluoride. In this case the water would be unfit for drinking purposes. Although waters containing natural fluoride ion above normal maximum solubility might be found, I assume that the natives would usually drink from a purer source.

The healthy development of mankind, prior to a filtered and piped water supply, was based on drinking collected rainwater, spring, stream or shallow well water, and not on regularly drinking water from active volcanic regions, peat-bogs, or other unhealthy waters which could provide the ions necessary for increasing fluoride solubility. Natural fluoride ion concentrations much greater than 0.1 ppm in the fresh water systems of the world are rare.

Data gathered together by the World Health Organisation (Reference 4) concerning the concentration of fluoride in waters around the world, shows confusion between fluoride, fluorine and fluoride compounds expressed as ppm, and indicates the possibility of either misplaced decimal points in some instances, or early unreliable techniques of fluoride estimation. Consequently, the reported cases of fluoroses are likely to be due to a lower concentration of fluoride ion than is supposed. It is difficult to accept that anyone could consistently take in around 80mg of natural fluoride ion daily, as this would involve drinking eight to ten litres of water containing eight to l0mg per litre, or a little less allowing for fluoride in food and tea. The British Dental Association (Reference 5) also confuses fluoride ions and fluoride compounds where it reports, “chronic poisoning … in excess of 20mg daily", meaning 9mg of fluoride ion from 20mg of NaF.

In The Probe (Vol. 18, No. 3, p. 85) the author (Reference 6) proved scientifically, in a statistical manner, that the effect of fluoride in reducing dental caries is trivial to non-existent. This paper indicates that a smaller dose of fluoride is able to produce effects more harmful than generally supposed. The safety margin is not as large as that which one is led to believe. Once again, science rejects the exaggerated claims of the professions.

If artificial fluoride is added to the water supply, then lime water, Ca(OH)2, will also have to be added, especially to soft waters. Ostensibly, lime water is added to stop iron from leaching out of pipes. Another reason, seldom admitted or forgotten, is to provide enough calcium and alkalinity to reduce the cytotoxicity of acid solutions of fluoride (Reference 7). What was once a near neutral water a little above pH7, becomes an alkaline water having the taste spoiled, and incidentally making lime-sensitive plants less able to cope with their environment.

Since the fluoridation of Birmingham's water supply in the early 1960s the hydrogen ion concentration has often been at pH 8.6. At this pH there is a danger of Vibrio cholerae proliferating, especially in hot weather, and so chlorination is, or should be, maintained at maximum level.

The established facts concerning fluoride toxicity (Reference 8, 5, 3) are probably well-known. A single 250mg dose of NaF is known to cause severe acute symptoms of poisoning, and a larger dose can be fatal within a few hours. Acute symptoms of poisoning have been reported with doses from 20-140mg. A single 200mg dose of Na2SiF6 is fatal, and H2SiF6 is more toxic, dose for dose. This toxicity presents handling difficulties to water authority operatives, and there is no method of monitoring low-grade toxicity. 20mg per day of NaF can cause severe symptoms of chronic poisoning. Fluoride has a special affinity for the bones and teeth, this is how the body tries to deposit out of harm's way the excess fluoride not eliminated by the kidneys.

In drinking water:

4-8ppm fluoride ion can eventually cause skeletal fluorosis (an unnatural thickening of bones - vertebrae, pelvis and long bones, sometimes with severe pain).

4ppm fluoride ion makes teeth hypoplastic (dental enamel chips and flakes), and produces severe dental fluorosis (mottling of teeth).

2-2.5ppm fluoride ion causes brown spots to appear on the teeth of most persons.

1ppm of fluoride ion causes dental fluorosis in about 10 per cent of the population.

The safety margin is not as great as that demanded of many pharmaceutical preparations, and treatment lasts for a lifetime. Also, the dose is uncontrolled, varying widely with fluid intake and amounts received from extraneous sources. Hypersensitive individuals are always a drug risk, and cases of skeletal fluorosis have been reported with fluoride levels of 1 to 3 ppm in water in tropical countries.

Many minor ailments, especially gastro-intestinal complaints and disturbances of vision, of a distressing nature in children, attributed to fluoride in the water supply have been reported in the world's scientific literature, but these reports have been either not fully substantiated or ignored. Several major diseases have been linked with fluoride, but the cause and effect relationship is far from being proved. On the other hand, neither the National Water Council nor the Severn-Trent Water Authority, both of which seem ever ready to say yes to fluoridation, nor any other authoritative body is able to supply the following toxicity test data for NaF, Na2SiF6, and H2SiF6:

(a) Acute toxicity LDP tests.

(b) Chronic toxicity tests using two species of animal, one non-rodent, at three appropriate dose levels over three months, six months and several years, involving haematology, blood chemistry and enzymology studies, urine analysis, skeletal examination, and complete pathology (gross and microscopical).

(c) Reproductive toxicity tests. Teratogenicity.

(d) Fertility tests.

Such toxicity tests are mandatory as required by the (Dunlop) Committee on the Safety of Medicines of every pharmaceutical manufacturer.

However much it might be argued at present that toxicity tests are not required of water authorities, or that fluoride is not a medicine (in which case it will have to be classified as a poison), it might be possible to prove eventually that the practice of fluoridation as carried out by, water authorities is ultra vires.

Recently, an eminent British QC has given a detailed opinion on a documentary issue drawn by a firm of British lawyers (Reference 9), that fluoridation of the nation's water supplies is illegal, and that water authorities do not have power under the Water Act, 1973, to add chemicals to water for medical purposes. Those authorities and individuals who have so far authorised fluoridation could be laying themselves open to potentially vast claims for damages, especially if radiological evidence shows osteosclerosis.

The power for water or other authorities to undertake compulsory mass medication through the water supply must be expressly and specifically conferred by statute. Either the Government will be forced to try to introduce the required legislation through Parliament, or a County, City or District Council which feels strongly enough against compulsory fluoridation might pursue litigation through the British Courts, and if necessary appeal to the European Court of Human Rights. The scene is set for a legal battle which might, or might not, take place in the near future.

I should like to put forward a new issue which could make redundant any thought of legal action by either side.

The people of this country are now in a situation where any criminal can easily obtain without traceability an almost tasteless, odourless, colourless, thermostable, potent poison. All a villain has to do to obtain such a powerful poison is to turn on the tap of a fluoridated public water supply in the privacy of his home, and boil off the water in a large vessel, to obtain the highly soluble fluoride in a small volume. By aggregating a number of these small volumes, and boiling the mixture down, it is easy for anyone to obtain a concentrated solution of poison in small volume. This could then be administered at will in food and drink. The chronic poisoning of the victim, or fatality, would be difficult to prove as a deliberate act. Can the Home Secretary ignore this development? If so, we do indeed live in a foolish and dangerous time.

References: 

1. Handbook of Chemistry and Physics, 1967-1968, C.R.C.

2. Fluorine Chemistry Vol. I, 1950, Academic Press N.Y.

3. Fluoride Teeth and Health. A Report of The Royal College of Physicians, 1976, Pitman Medical.

4. Fluorides and Human Health. World Health Organisation, 1970, Geneva.

5. Fluoridation of Water Supplies. The British Dental Association, The Fluoridation Society, and The Health Education Council, 1976.

6. Harris, M. Fluoridation: Statistical Evaluation of Data. The Probe, September 1976, Vol. 18, No. 3, p.85.

7. Helgeland, K. and Leirskar, J. pH and the Cytotoxicity of Fluoride in an Animal Cell Culture. Scand. J. Dent. Res. 1976, 84, 37.

8. Martindale. The Extra Pharmacopoeia. The Pharmaceutical Press, Current 26th Ed.

9. Documents in possession of the National Pure Water Association.