CLEAR AND PRESENT DANGER

Fluoride first entered the public consciousness as part of a post-war new dawn, when science would unerringly lead the way to a better life for all. It came to assume almost magical properties as a wholly salutary chemical. Today, every science textbook and encyclopaedia refers to its capacity for inhibiting dental decay, especially among children.

The experts told us that fluoride both helped the remineralisation of enamel (the outer layer of the teeth), and also prevented the production by bacteria in dental plaque of the acid that causes decay. As the dental authorities became ever more zealous in the promotion of fluoride, it was delivered to the population, either through the fluoridation of the public water supply, or by fluoride in toothpaste and other dental supplements.

Fluoridation was essentially a socialist health policy. It made scant difference to the teeth of children from secure backgrounds, who already benefited from the twin advantages of nutritious diet and regular dental hygiene; but fluoride looked after all the others. In the phrase often cited by dental professionals, it gave poor kids rich teeth.

There were those who counselled caution, on the grounds that fluoride is a cumulative poison; and that, in any case, rates of dental decay were also falling dramatically in countries that did not espouse its use. But in Britain these countervailing arguments went unheeded. The concept of fluoride as a supremely benign aid was instilled in generations of dental students.

The idea was an American import. As a whole, Europe has never been persuaded. Only about 2 per cent has artificially fluoridated water supplies, and virtually all of that is accounted for by Britain (10 per cent of the country) and Ireland (66 per cent). In England, Birmingham fluoridated in 1964; Britain's second city was desperate to be first at something. Newcastle followed a few years later. Thus, today, the main fluoridated areas are the West Midlands and the North-East, and other discrete parts of the country: Crewe and Nantwich, west Cumbria, Scunthorpe and parts of Lincolnshire and Bedfordshire. Some areas also have naturally fluoridated water.

There have been no recent fluoridation schemes in Britain, but this hasn't been for lack of trying by the British Fluoridation Society (BFS), the body funded by the Department of Health that spearheads the pro-fluoride campaign. To improve dental health still further, the BFS wants other urban areas to be fluoridated - there is a working party to fluoridate inner London - so that one in four of the population receive fluoridated water rather than the present level of just one in ten.

Yet, on one obvious level, the fluoridation of the public water supply is an absurd concept. We all know what happens to the nation's water: about one-third is lost in leakages before it ever gets anywhere; seven-eighths of the rest is used by industry, and much of the remainder literally goes straight down the toilet. The proportion that reaches our teeth is tiny indeed.

Those with special requirements will be badly inconvenienced. Some industries - notably those dealing with photographic or X-Ray equipment - need first to remove the fluoride. People on dialysis cannot receive fluoridated water. Mothers with newly-born babies are best advised not to make up compound baby feed with fluoridated tap-water.

And this isn't all that is bizarre about fluoridation. Assuming, for the moment, that fluoride actually achieves everything that is claimed for it with respect to teeth, how do those fluoride ions know that, when they come cascading into the body, they must strengthen the resistance of teeth to decay, but do nothing else at all. Isn't it, on the contrary, common sense to assume that if teeth are being affected, then so are other parts of the body? In fact, Birmingham, with its long-time fluoridated water, does very well nationally in terms of dental decay; but in several other measurements of public health, it performs poorly. A number of scientists believe that these factors are not unconnected.

Amid all the claim and counter-claim about fluoride, there are some indisputable facts. The first is that, of all the fluoride taken into the body, about 50 per cent is excreted. The rest remains. In its major 1993 report, Health Effects Of Ingested Fluoride, the US National Research Council (NRC) pointed out that, `Half the fluoride [taken in by the body] becomes associated with teeth and bones within 24 hours of ingestion. In growing children, even more of the fluoride is retained.' For many years, dental authorities have confidently asserted that whereas fluoride's impact on the teeth is striking and wonderfully beneficial, its impact on bones, even over a lifetime, is non-existent. There is now increasing evidence that this is exactly what it seems: an illogical proposition.

During the Nineties, a steady trickle of scientific reports has found a `statistically significant' association between water fluoridation and increased risk of hip fracture. The suggestion is that the hip needs tensile strength, but that this is destroyed by fluoride. One study monitored the hip fracture rates of white women across 3,000 counties in the US. Another compared the incidence of hip fracture among mainly Mormon communities in Utah. This was of particular interest because it could exclude confounding factors such as smoking and alcohol consumption. (Smoking is generally thought to increase the risk of osteoporosis.) The study found a `small but significant' additional risk of hip fracture among both men and women exposed to artificial fluoridation at one part per million - precisely the level at which water is fluoridated in the UK.

In England, a study concluded that there was no association; but, after revising their statistics and weighting them for population density, the researchers concluded that there was `a significant positive correlation between fluoride levels and [hospital] discharge rates for hip fracture'.

These were potentially disturbing findings. Andrew Thomas, consultant surgeon at Birmingham's Royal Orthopaedic Hospital, commented that there was a need for further and more specific research. `What we need to do,' he explained, `is to look at patients with osteoporosis, to look at the levels of fluoride in their bone so that we can assess whether there really is a problem or not.' The urgent need for further investigation was made even plainer by the publication of a fresh and more alarming study by the University of Bordeaux, published in the Journal Of The American Medical Association. This measured rates of hip fracture among elderly citizens in 75 parishes of south-western France, and compared the concentrations of fluoride in the water (which, in this case, was naturally fluoridated). The study found that people living their lives in fluoridated areas suffered 86 per cent more fractures than those living in non-fluoridated parts.

One irony of this research is that those who lobby in favour of fluoridation always refer to the savings to the National Health Service in costs of dental care - however, if fluoridation does indeed lead to an increased incidence of hip fracture, then the overall costs to the NHS would be far greater than these projected savings. Hip fracture, a serious and sometimes life-threatening condition, is one of the most expensive items on the NHS budget.

Nor is it just hip fractures that may result from the impact of fluoride on bones. Cases of crippling skeletal fluorosis, a condition directly caused by fluoride, are exceptionally rare, except in countries of naturally high fluoride levels such as India; but the early stages of the condition could perhaps be triggered by artificially-fluoridated water supplies. Fluoride, which is deposited in mineralising new bone more easily than existing bone, distorts the natural regeneration of the bone. As fluoride accumulates, so the bones become thickened and develop outgrowths. Tendons and ligaments may then be affected, and nerves may become trapped and damaged.

The result could be a mounting toll of skeletal problems - from occasional stiffness or pain in the joints, to backache and osteoarthritis. These problems collectively form one of the major causes of absence from work in this country, so their impact on the economy - even aside from the well-being of the individual - is considerable.

Scientists have also considered whether fluoride has further incapacitating effects. Research undertaken in the US for the National Toxicology Program (NTP) in 1990 and 1991 showed `a possible increase in osteosarcomas in male rats' exposed to fluoride. Osteosarcoma is rare, but it is one of the principal cancers of childhood. As a result of the NTP report, the Department of Health in New Jersey commissioned work to assess the incidence of osteosarcoma in the state in relation to water fluoridation. The results were astonishing: they indicated that in male children (under the age of 20), the risk of osteosarcoma was between two and seven times greater in fluoridated water areas

Dr Sheila Gibson, of the Glasgow Homoeopathic Hospital, reported further serious findings in a paper in Complementary Medical Research. By adding sodium fluoride to blood samples, she demonstrated that fluoride impaired the functioning of the immune system. Then there is concern about the genotoxicity of fluoride, and its possible role in the cause of increased levels of infant mortality and Down's Syndrome births. Certainly, Birmingham has very good antenatal facilities; yet, as the West Midlands Perinatal Audit commented, the city has `significantly higher' rates of stillbirth and neonatal mortality than the average for England and Wales.

Could this be attributable to fluoride? In an as-yet unpublished paper, Ian Packington, a toxicologist on the advisory panel of the National Pure Water Association (an anti-fluoride campaign group), records that in the years 1990-92 perinatal deaths in the fluoridated parts of the West Midlands were 15 per cent higher than in neighbouring unexposed areas such as Shropshire and Herefordshire (even though the latter had higher `Townsend scores' - an index of social deprivation). From an analysis of Department of Health statistics, he also concluded that in the period 1983-86 cases of Down's Syndrome were 30 per cent higher in fluoridated than non-fluoridated areas.

These were not isolated findings. In the 1970s, Dr Albert Schatz reported that the artificial fluoridation of drinking water in Latin American countries was associated with increased rates of infant mortality and deaths due to congenital malformation. As long ago as the 1950s, Dr Ionel Rapaport published studies showing links between Down's Syndrome and natural fluoridation.

The fluoride ion - unlike the fluorine molecule, one of the most reactive elements in the periodic table - is very stable. It was unclear how it could potentially cause ante-natal damage of this kind - until, in 1981, the Journal Of The American Chemical Society reported fresh research that fluoride could form strong hydrogen bonds. This could indeed have serious repercussions for biological systems, with the consequences of affecting proteins, other molecules and DNA. Dr John Emsley, the scientist conducting the research, wrote that, `We believe we have found an explanation of how this reputedly inert ion could disrupt key sites in biological systems.' Even so, worse was still to come. The NRC report on the effects of fluoride clearly conceded that there were `inconsistencies' in the data about fluoride toxicity and `gaps in knowledge'. One area it did not examine at all was the effect of fluoride on the brain and central nervous system - even though the results of relevant Russian studies in the 1970s were by then widely known. These demonstrated that workers suffering from exposure to fluoride in the workplace exhibited signs of impaired mental functioning.

The NCR's omission was put into sharp perspective with the publication in 1995 of work by the neurotoxicist, Dr Phyllis Mullinex. In the 1980s, she developed a sensitive test using animal models to ascertain the effects of neurotoxins on the central nervous system. As a result, she was recruited to head the department of toxicology at the Forsyth Dental Institute in Boston. Everything went well until she stepped into politically-sensitive territory by using her system to test the effects of fluoride.

She noted disruption to the behaviour patterns of rats, and concluded that fluoride adversely affected the brain. She went on to show that fluoride accumulated in brain tissue, and that its effects depended on the age of exposure (the younger were more vulnerable). She also determined that these effects were measurable at a lower level of exposure to fluoride than was necessary to produce damage to the bones.

In order to receive her next tranche of funding, she presented her interim findings to representatives of the major manufacturers of toothpaste. She was asked, `Are you telling us that we're reducing children's IQs by putting fluoride in toothpaste?' She replied, `Well, basically, yes.' She did not receive further funding. And, although her paper was peer-reviewed and subsequently published in Neurotoxicology And Teratology, she was told that her work was `not relevant to dentistry' and sacked from her post at the Forsyth. (She retained her second post, at Harvard Medical School.) She sued the Forsyth for wrongful dismissal, and last month won what is believed to be a substantial out-of-court settlement.

The disturbing conclusions of her work have lately been buttressed by new studies from China, published in the magazine Fluoride. Researchers compared the IQs of children in areas of low and high natural fluoridation, and discovered that children in the low fluoride area had higher IQs. There was some criticism that this work had not taken sufficient account of possible confounding factors. So a small-scale study was initiated, comparing two villages, Sima, with a high level of natural fluoride, and Xinhua. The results were the same as before. The children exposed to higher levels of fluoride had lower IQ levels.

Paul Connett, who was born in Brighton, is today professor of chemistry at St Laurence University in New York state, and an international authority on environmental toxins. Until it was proposed to fluoridate his own community, he had always avoided the fluoride debate. `I now realise that, because the pro-fluoride lobby has successfully portrayed the anti-fluoridationists as a bunch of crackpots, people have been kept away from this issue. In fact, once I looked into the literature and was, quite frankly, appalled by the poor science underpinning fluoridation, I had grave concerns about the wisdom of putting this toxic substance into our drinking water. The dental authorities say there is no scientific proof of harm. That's like the joke about the guy who jumps out of a 20-storey building and, as he's passing the ninth floor, says, `Okay, so far'.' In the US, at the same time that the first fluoridation scheme was being introduced, scientists were admitting (in documents hitherto secret, but now disclosed under the Freedom Of Information Act) that they had no idea what the effects of low-level exposure would be. The first such scheme was introduced in Grand Rapids, Michigan, in 1945 as a long-term pilot study. Over a 15-year period, it was to be compared with an unfluoridated control city, Muskegon, to determine whether fluoride actually did benefit dental health. The Americans couldn't wait 15 years, however; or even two. The following year, six cities opted to fluoridate. In 1947, 87 did, including Muskegon. In a prime example of the bureaucrats pre-empting science, the authorities decreed that it was unfair to deprive its citizens of the `benefits' of fluoridation. The 15-year study had run for just 18 months.

Thus there has never been a single long-term, scientifically inviolable study of fluoridation. And this is against a background of steady improvements in dental health, with the widespread, indeed ubiquitous, availability of fluoride toothpaste. But since cleaning one's teeth is always beneficial, how much real additional advantage does the fluoride confer? There are, of course, those who argue that the Grand Rapids study was not allowed to run its full course precisely because the results would have capsized the pro-fluoride arguments.

In New Zealand, Dr John Colquhoun, chief dental officer of Auckland, examined the dental records of all schoolchildren from 1980-90, the better to promote his objective of fluoridating the whole country. To his surprise and concern, he discovered errors in study design, some fabrication of statistics, and no advantage at all from fluoridation. He subsequently reversed his opinions about fluoride, and founded the International Society For Fluoride Research.

Similarly, Dr Richard Foulkes, special consultant to the health minister in British Columbia, Canada, recommended mandatory fluoridation. It didn't happen, however, for in most parts of the province, the populace was opposed. Almost 20 years later, the director of dentistry examined the records and discovered the public's instinct had been correct. The records of schoolchildren from fluoridated and non-fluoridated areas suggested that there was no benefit in fluoridation.

All this naturally begs the question: why has there been such unrelenting administrative pressure to fluoridate? Conspiracy theorists would point to the confluence of interests of the sugar industry, keen to identify any method of improving dental health which did not involve consuming less sugar, and huge industrial concerns, such as aluminium manufacturers, petro-chemical and fertiliser industries, for all of whom fluoride was a waste product and a dangerous pollutant. Accordingly, they welcomed the opportunity both to launder the image of fluoride and (in some instances) to sell to water companies something they would otherwise have had to pay to get rid of.

The dental profession itself tells a very different story. In 1945, a physician noticed something different about the teeth of children living in high fluoride areas: they were mottled and discoloured. The condition - fluorosis - was caused by fluoride attacking the enamel of the permanent teeth while they were being formed in the gums. When they erupted, they had unsightly stains on them.

However, the physician also believed that the children with fluorosis had fewer dental caries. Thus, the link was made, and the aim was formulated of trying to fluoridate to a uniform level for the benefit of dental health. The optimal level, at which benefits to teeth could be reconciled with an acceptable level of fluorosis, was determined as one part per million of fluoride in water.

From the outset, the danger of fluorosis was inherent in the dental lobby's advocacy of fluoride - it was recognised that some children would need to sacrifice their appearance for what was deemed to be the greater good. In recent years, however, dental fluorosis (the majority of cases are only mild) has been increasing. In the US, the NRC expects fluorosis to occur, albeit in a mild form, in 10 per cent of the population. Statistics showed that in one (unnamed) city with a fluoride concentration of twice the recommended level, the prevalence of dental fluorosis in children was 53 per cent. In Britain, there is now a national register of children suffering from fluorosis.

Fluorosis is considered a cosmetic and not an adverse health effect (and thus treatment cannot be obtained on the NHS, which seems churlish when it was the health authorities that caused the problem in the first place). However, this definition is increasingly being questioned, especially on two grounds. First, fluorosis strikes when the child is at a psychologically vulnerable age. At an international conference on fluoridation in Birmingham in 1995, evidence was presented that, in Australia, `even mild [fluorosis] was associated with psycho-behavioural impacts'. Second, dental fluorosis is merely the visible sign of fluoride's effects - so is that the extent of the problem? Or is there other damage which cannot be seen? The worldwide increase in fluorosis is hardly surprising, as exposure to fluoride from sources other than the water supply has increased immeasurably over the past 25 years. Even for those of us not living in fluoridated areas, there is constant exposure from toothpaste, from other dental products, from fruit and vegetables, on which the pesticide residues will contain fluoride - and from drinks such as tea, which has naturally high fluoride levels as tea grows best in a fluoride soil.

In 1945, the dental authorities set the optimal level for fluoridation at one part per million; and the optimal level today is still one ppm. Logically, that cannot be correct, because overall exposure has increased so much in the interim. Moreover, the absolute level of fluoride exposure is of critical importance because the whole debate is so finely balanced. As Professor Connett explained: `From a toxicological point of view, the gap between the therapeutic dose - the level at which fluoride is supposed to benefit teeth - and the toxic dose, at which it begins to do serious harm, is very small. Usually, you want a factor of a hundred between the two. In this case, it's tiny. The optimal level in drinking water is one ppm. The maximum contaminant level, as prescribed by the US Environmental Protection Agency, is four ppm. That gap is far too small for public safety.' Faced with accumulating information of this kind, the dental administrators and pharmaceutical companies have been quietly moving the goalposts. Neither the general public, nor even qualified pharmacists, probably have any idea what the current recommendations are.

In the first place, no one should be taking fluoride supplements, and particularly not if they live in a fluoridated area. The problem here is that many millions of people probably have no idea whether they're living in a fluoridated area or not, because no one has ever had the courtesy to tell them. Second, to quote the leading textbook Essentials Of Dental Caries, `topical fluoride preparations [toothpaste et al] should be applied carefully because of their potential toxic effects'. Children should be supervised by parents when brushing their teeth. They should use only a pea-sized amount of fluoride toothpaste - though no one would ever suppose as much from watching the television commercials - and should on no account swallow it. The chairman of the British Fluoridation Society, Professor Mike Lennon, blames the increased incidence of dental fluorosis on children `abusing' (that is, swallowing) toothpaste.

Since it is difficult not to swallow toothpaste, and since fluoride is in any case absorbed through the gums, parents may instead like to purchase non-fluoride toothpaste - were it not that this is almost impossible in many parts of the country, as the supermarkets and pharmaceutical retailers have severely restricted consumer choice.

So, the real route to lasting dental health remains, as ever, regular dental hygiene and a nutritious diet. In fact, the most remarkable aspect of the conduct of the dental lobby has been not its unquestioning espousal of fluoride but its cowardice in not confronting the huge commercial sugar interests. After all, dental caries were unknown before refined sugars. We would all be able to improve our dental records and lead healthier lives if food manufacturers were forced to state, clearly and unequivocally, what percentage of each product (an ostensibly healthy carton of yoghurt, for example) was composed of sugar.

To risk so much for the sake of so little (whoever wants to prevent the occasional filling if children's mental development is at stake?) really is extraordinary. The possible subtle effects of long-term exposure to low levels of fluoride can no longer be ignored. Those who wish to extend fluoridation schemes throughout the country tell us that there's `no evidence' that it causes harm; we must bear in mind how carefully the authorities have avoided gathering the evidence.

The final irony is that fluoridation, having been introduced to bridge the socio-economic gulf in society, probably benefits the poor least of all. It is precisely those suffering poor nutrition, and hence vitamin and mineral deficiencies, who will be most vulnerable to fluoride's toxic effects. One of my favourite books of last year was Robert Youngson and Ian Schott's Medical Blunders. It already contains a huge amount of material, but surely a future edition will have to find room for a chapter on the fluoridation of public water.

Health Alert: Don't Swallow Your Toothpaste, produced by Bob Woffinden, will be shown on Channel 4 on Thursday June 19 at 8pm.

This text may not be republished or reproduced without prior authorisation of the Guardian Syndication Department. Contact Sonia Singleton 171 713 4310.