Two weeks ago it emerged that Mr Blair is backing secret moves to force water companies to fluoridate drinking water, whether the industry likes it or not. In other words, he is proposing to mass medicate the people of this country. This is not – as you might imagine – to prevent some terrible, crushing health risk like smallpox, but to improve the quality of our teeth.

Tooth decay is a nuisance, but it’s hardly the stuff of nightmares. Fluoride, on the other hand, may well be; and, according to countless studies around the world, it doesn’t even work. In the US, where 65 per cent of the population are routinely subjected to the chemical, the worst tooth decay occurs in poor neighbourhoods of the largest cities – the vast majority of which have been fluoridated for decades. And when fluoridation was stopped in parts of Finland, East Germany, Cuba and Canada tooth decay actually decreased.

But even if it did work, drinking fluoride to prevent cavities is like swallowing bandages to cure a broken arm. To solve tooth decay the government has opted not for a campaign against the undisputed culprits – like fast food and sugar – but for mass medication with a useless medicine.

Fluoride is not just a useless medicine. It is also highly toxic; so toxic, in fact, that in 1984 Procter and Gamble admitted that a small tube of its Colgate toothpaste ‘theoretically. . . contains enough fluoride to kill a small child’. Given the fact that a third of US children living in fluoridated areas have white specks (or, in more serious cases, dark stripes) across their teeth – a sure sign of fluoride over-dose -, the implications are alarming.

Last year the director of the University of Toronto’s Preventative Dentistry department, Dr Hardy Limeback, announced that he had profoundly corrected his profluoride position after reviewing the available literature. It must have taken him some time.

Fluoride has been linked to cot death, eczema and Alzheimer’s. It has been shown, at low doses, to cause genetic damage. It has even been blamed by doctors from the US’s National Cancer Institute and National Health Federation for 35,000 cancer deaths every year.

And because fluoride disintegrates collagen, an essential structural component in skin, muscle, ligaments and bone, big question marks are being raised over its possible contribution to arthritis – a problem that now affects a staggering 70 million Americans.

Other reports are appearing with increasing regularity that link fluoride consumption to increased hip fractures among the elderly.

Still further studies have linked fluoride use to hypothyroidism (underactive thyroid glands), which is one of the most widespread medical problems in the US – affecting more than 20 million people – and leads to fatigue, weight gain, depression and heart disease. The suggestion of such a link is hardly radical; fluoride used to be prescribed by European doctors to depress the activities of an overactive thyroid.

But what is shocking is that fluoride was ever considered for mass medication. It has always been a source of contention. Indeed the first ever lawsuits against the US government’s nuclear bomb programme (the so-called Manhattan Project) concerned fluoride, not radiation. What is more, the first health tests for fluoride, conducted by a Dr Dean, were designed to establish how much of the substance industry could afford to release into the environment without damaging human health.

In the summer of 1943 a group of New Jersey farmers reported that something was ‘burning up’ their peach trees, maiming their horses and cattle and killing their chickens. The source of their ills was a nearby DuPont factory that was producing millions of pounds of fluoride for use in the Manhattan Project. Immediately following the war the farmers filed a suit against DuPont and, without realising it, triggered alarm bells throughout the government. At the time, the Manhattan Project’s chief of fluoride toxicology studies, professor Harold C Hodge, asked his superiors if there ‘would be any use in making attempts to counteract the local fear of fluoride through lectures on fluoride toxicology and the usefulness of fluoride in tooth health?’ As we now know, that is exactly what happened – with the effect that fluoride was magically transformed from a killer to a panacea.

Some years later Dr Phyllis Mullenix, formerly the head of toxicology at Forsyth Dental Center in Boston, conducted animal studies that showed fluoride was a powerful central nervous system toxin – even at low doses. Her results were published, and Mullenix was startled when the US National Institute of Health rejected her conclusions out of hand and terminated her grant.

Mullenix’s research was not as original as she thought, however. Similar studies had been carried out by dentists involved in the Manhattan Project; the results had demonstrated a ‘marked central nervous system effect’ from fluoride. A version of the study was published in 1948, but, according to the investigative journalists who uncovered the original, it was ‘censored to the point of tragicomedy’. While the published version reported that the factory workers studied exhibited fewer cavities, the original reported that most of them no longer exhibited any teeth at all.

Since then, the most widely known study into the benefits of water fluoridation was conducted in New Zealand between 1954 and 1970. The so-called ‘Hastings experiment’ is still quoted by fluoridation advocates today. But it failed to meet the most basic criteria for scientific objectivity; not least because the decline in tooth decay that the community in the study experienced was also seen in non-fluoridated communities in the region. The then mayor of Auckland, Sir Dove Myer Robinson, described the Hastings experiment as a ‘swindle’.

Tragically the people the British government ostensibly wants to help most – ie, the poor – are the very people who will be worst hit by fluoride contamination. Studies by the American Dental Association in 1957 and the Canadian National Research Council in 1977 showed that ‘people with inadequate dietary intakes are likely to be more “at risk” as a consequence of long-term low-dose fluoride ingestion’.

The British government’s public health and water ministers, respectively Hazel Blears and Elliot Morley, recently issued a letter in which they suggested with breathtaking arrogance that ‘those who remain adamantly opposed would be able to use water filters that remove fluoride or buy bottled drinking water’. But why should we have to? If people want to subject their children to a highly suspect industrial poison, they are free to do so, on their own terms. That is the position of virtually every country in Europe.