What links your toothpaste to the atomic bomb and the world’s most corrosive acid? Fluoride has been added to Bedfordshire’s water with little or no public debate.

GARRICK ALDER reports on one campaigner who refuses to go with the flow.

Cynthia Bagchi is shocked but not surprised.

Another health study showing the negative effects of fluoridated tap water has just been published.

In County Donegal, Northern Ireland, tapwater is fluoridated.

A series of tests by an American university has shown that the inhabitants of the county are being exposed to fluoride levels way above UK Food Standards Agency guidelines.

Quoted in the press, the university’s professor Paul Connett said: “Many thousands of people in Ireland are at risk of skeletal fluorosis.”

Cynthia Bagchi – wife of former mayor Apu – has been worried about fluoridation for five years, ever since she stumbled onto the issue while running an allergy support group.

Mrs Bagchi told Bedfordshire on Sunday: “Tens of thousands of people in the UK, including babies, are probably being exposed to seriously unsafe amounts of fluoride.”

But why? And how? And what is ‘skeletal fluorosis’? In order to answer those questions, we need to explain what fluoride actually is and why it is in our water at all.

Fluorine, a gas, is the lightest member of a family of chemical elements called the halogens, the most reactive elements in the universe.

Chlorine in water produces hydrochloric acid, and is therefore used in minute amounts to disinfect swimming pools.

Fluorine is the most reactive halogen – a gentle jet of it will make even asbestos glow red hot.

One of fluorine’s compounds is hexafluorosilicic acid (HFSA), one of the most corrosive acids in the world.

HFSA is so active that it can’t be stored in glass bottles or in unlined metal containers – the liquid will simply eat its way out.

HFSA is also the fluoride in ‘fluoridated’ water.

At a concentration of one part in a million, it is unable to dissolve anything.

The principle is that fluoride in water will help prevent dental cavities by strengthening teeth.

But because water is freely available, anyone using tapwater is exposed to an uncontrolled dose of fluoride while drinking tea, having a bath, brushing their teeth, or any number of other household activities.

And this is where the problems arise because fluoride is known to poison the central nervous system in large doses.

The effects include lowered intelligence and reduced memory.

In 1992, large amounts of fluoride were accidentally released into the drinking water for an Alaskan village where 219 people were poisoned and one died.

Fluoride’s reactivity means it gets absorbed into bones, displacing calcium.

Long-term fluoride overexposure creates something called skeletal fluoridosis, giving a variety of bone problems.

Ironically enough, the main warning sign of fluoridosis is mottled cracked teeth.

Yet the main evidence for the fluoridation movement – which arose in America after the Second World War – was that children seemed to have fewer cavities in some areas with naturally fluoridated water.

One claim about the fluoridation movement is that it received a major boost when the USA’s atomic weapons programme discovered it had accidentally manufactured thousands of tonnes of HSFA that it couldn’t get rid of safely.

Key documents are missing, which deepens the suspicions of some researchers.

Quite apart from the shadowy origins of fluoridation, there is an ethical aspect.

Did you ever agree to be treated for a medical condition (fragile teeth) with an experimental medicine in an uncontrolled dose?

In medical terms, you did not and so fluoridation is unethical and possibly illegal.

In political terms, the Blair government steamrollered fluoridation into UK law in the Health Act (2003).

Cynthia Bagchi said: “Fluoride is not an essential mineral of the body as has been taught.

“When fluoridation began in the 1950s there was no strict regulation in place.

“Evidence that fluoride can damage the brain has increased significantly, lowering IQ and altering behaviour.

“There have been 30 animal studies to show this effect already.

“The British Dental Association has warned mothers not to make up baby milk powder with fluoridated water, as this would be 250 times more fluoride than nature intended.

“I am saddened by how we have been so easily misled by those we trusted.”

An Anglian Water spokesman said: “Fluoridation increases the naturally occurring level of fluoride present in water.

“We do not supply medical expertise regarding fluoridation and dental health, but do provide health authorities with technical advice in relation to the operation of the water supply system, since our expertise lies in engineering and water treatment.

“The addition of fluoride to the water supply is a public health issue, not a water quality issue, and fluoridation is carried out in agreement with health authorities, at their request.”