Is fluoride too much to swallow?

What difference will it make, and should we drink it whether we like it or not? Nick Morrison reports.

IT'S a waste product from making fertiliser and it's almost as poisonous as arsenic, or it's a chemical we can all embrace without fear. Putting it in our water is a gross violation of human rights, or one of the most significant advances in public health over the last 50 years. When it comes to fluoride - and fluoridation of water - it seems there's no middle ground.

The battle over whether fluoride should be added to our water supplies has been raging for more than 40 years, with no sign hitherto that it is on the wane. But on Monday night, MPs took an important step towards resolving the issue in favour of the 'For' camp, by voting to give health authorities the power to force water companies to fluoridate. But the proposal still has a number of hurdles to clear before it becomes law, and already the forces of opposition are marshalling and a bitter fight is in prospect.

But what is this looming battle all about? What difference will it make if we have fluoride in our water? And why does the very mention of it provoke such passions?

Q. What is this fluoride which could be added to our water?

A. The fluoride in question is a waste product from the fertiliser industry and is untested on humans, according to Jane Jones, campaign director of the National Pure Water Association.

"Why would anyone want to pollute drinking water with industrial waste?" she says. "It is untested and unlicensed, and if it were tested it would fail."

But fluorides are naturally present in drinking water anyway, and in some places, including Hartlepool, are present in roughly the same quantities as would be added under the proposal. "Rather than adding some foreign chemical to the water, we're just topping up the natural levels," says Kate Lennon, of the British Fluoridation Society.

She also rejects the claim that it is untested and unsafe. Chlorine is added to water to kill bacteria, and there is no suggestion anyone should drink a glass of neat chlorine, she says. "Some people have been drinking fluoride all their lives in Hartlepool," she adds.

Q. So what are the benefits of adding fluoride to water?

A. Simply put, fluoride helps prevent tooth decay. A study by York University academics in 2000 estimated that it could reduce the number of teeth affected by decay by an average of two-and-a-quarter per person. "It would also increase the proportion of children who haven't got any tooth decay by about 15 per cent, and in a disease that affects half the child population, that is quite a significant benefit," says Kate Lennon.

David Walker, director of public health for the County Durham and Tees Valley Strategic Health Authority, adds: "We know that in fluoridated areas compared with non-fluoridated areas, the number of missing, filled or decayed teeth falls by half. But it is not just a matter of having fewer trips to the dentist. It is about improving self-esteem and quality of life."

Q. If it's so beneficial, why are some people opposed?

A. The main objection is that is a breach of human rights, according to Jane Jones. If it's in our water supply, we don't have any choice whether to drink it or not. "No one, not our elected representatives, not our Auntie Nelly, not our next door neighbour, has the right to say we should be medicated against our will. If a doctor did it, he would be struck off," she says. "No government can steal your human right - these are not up for grabs.

"People do not want to be treated by their drinking water. The dose is governed by the degree of thirst of the individual - how scientific is that?"

The only other situation when we can be treated without our permission is where we are judged mentally unfit, says Martyn Shrewsbury, health spokesman for the Green Party. He says one fear is that if it's fluoride today, what comes tomorrow? "It is rather like saying that if sufficient numbers of people are depressed, we should put Prozac in the drinking water," he says. Instead of adding fluoride, the Greens would like to see tooth decay tackled in other ways, such as imposing a levy on companies who aggressively promote sugary drinks to young children.

Q. So what do fluoridation supporters say about this?

A. "There is always a choice," says David Walker. "If you don't want to drink tap water, you can always drink bottled water, and the number of people who are drinking bottled water is increasing." And those who cannot afford bottled water, are those with most to gain from fluoridation, he claims.

"If you want to get good teeth, you have got to get fluoride one way or another. If you have got the money you can have dental fluoride treatments or buy the more expensive fluoride toothpastes. This way, everybody gets the benefits."

Nor is fluoride a special case, and all kinds of things are added to food products for health reasons, he says. Chlorine in water has a clear health benefit, and folic acid is added to flour used in bread to help prevent health problems in babies. "The benefits for the vast majority of people outweigh the freedom of choice for a small number of individuals," he adds.

And fluoridation will only be introduced after public consultation, and where the majority of the community is in favour, says Kate Lennon. "There is no question that water fluoridation would go ahead where there was not strong community support. Why should the minority deprive the community of a major benefit?" she asks.

Q. Are there any side-effects?

A. Fluoride increases the risk of osteoporosis, hip fractures, abnormalities in sperm and eggs and thyroid damage, according to the Green Party. "Fluoride chemicals are more toxic than lead and almost as poisonous as arsenic," says Mr Shrewsbury.

The most well-documented side-effect is fluorosis, where the teeth are mottled. Jane Jones cites one study where a third of children in five primary schools in Birmingham, where the water has been fluoridated since 1964, showed signs of fluorosis. "It is a bit like Russian roulette: whose kids are going to get it." The British Dental Association may be one of the most active supporters of fluoridation, but then dentists have much to gain from repairing affected teeth, she adds.

But while the York University review did highlight a higher prevalence of fluorosis, it can be remedied and it does not affect large numbers, says Dr Walker. "It can be fine mottling, or it can be quite gross, but dental fluorosis is uncommon and it is a cosmetic problem, not a health problem," he says. "The trade-off between fluorosis and tooth decay is overwhelmingly in favour of fluoridation. I believe that the public health benefits are considerable, and I don't think there are any credible risks."