ADVOCATES place it among the 10 most significant public health achievements of the 20th century.

They talk of it alongside medical milestones such as the eradication of smallpox and polio, the control of measles, rubella, tetanus and diphtheria and the recognition of tobacco as a health hazard.

But for every person in support of fluoridating town water supplies to improve dental health, it seems there is another who is against.

The debate has reared its head again as Brisbane City Council reconsiders its position to keep the city’s water supply free from fluoride.

A spokesman for Lord Mayor Campbell Newman said the council would have a better idea in six months on what direction it intended to take.

The issue has also been the subject of a recent Private Member’s Bill introduced into State Parliament by the Liberals, seeking to override local authorities and force the introduction of fluoride into all Queensland water supplies.

Queensland is the only state in Australia not to fluoridate its water. The exceptions make up about 5 per cent of the state, with water in Townsville, Dalby, Mareeba and Moranbah fluoridated.

Australia is one of six countries to fluoridate water, along with the United States, New Zealand, Ireland, Singapore and Colombia.

Opponents say fluoride is a form of mass medication linked to a host of health problems and that studies show tooth decay has declined at a similar rates in all Western countries regardless of fluoridated water supplies.

On the other side, the Australian Dental Association, backed by bodies such as the World Health Organisation, the Australian Medical Association and the American Dental Association, says that fluoridation reduces tooth decay by 20 to 40 per cent.

So who to believe?

There are many arguments against fluoridation, including ethical ones, and ingesting fluoride has been linked to brain damage, osteoporosis, cancer, thyroid and behavioural problems.

Other concerns are the hazard to bones and teeth in the form of skeletal and dental fluorosis.

Dental fluorosis is a mottling of the teeth that permanently damages enamel, while skeletal fluorosis is a disease that causes structural damage to bones and calcification of joints and ligaments.

Environmental scientist Mark Diesendorf, who has 20 years’ experience arguing against fluoride, said there was a high prevalence of skeletal fluorosis in naturally fluoridated areas of India, China, Persian Gulf countries and Africa.

He said skeletal fluorosis, in its early forms, was “indistinguishable from arthritis, a disease which is becoming more prevalent in two of the most extensively fluoridated countries, the US and Australia”.

In his paper Four Arguments Against the Fluoridation of Water Supplies, Dr Diesendorf said that as we aged the amount of fluoride stored in our bones steadily increased, gradually making them more fragile.

He said studies showed a higher rate of hip fracture in artificially fluoridated areas.

Studies have also found dental fluorosis rates in fluoridated communities have been as high as 40 per cent.

However, Australian Dental Association president David Houghton said fluorosis was a concern only with high levels of fluoride.

“In order to get fluorosis, you have to have significantly higher amounts of fluoride than what is added to water supplies,” he said.

“All reputable health authorities throughout the world have looked at all of these claims and they have rejected them.

“The anti-fluoride lobby lets emotion run away with reason. They come up with any number of spurious claims, so the onus should be on them to prove their point instead of scaremongering.

“Fluoride is the most effective and equitable way of preventing tooth decay.

“Data shows that dental decay rates in Brisbane are higher than the rest of the capital cities around the country and it basically boils down to a lack of fluoride.

“Our communities can’t afford not to be fluoridated.”

On its website, the ADA states “dental fluorosis continues to be the single harmful effect on teeth if a child is exposed to high levels of fluoride”.

It says there was “a relatively high incidence of low-grade fluorosis in some child populations in the late 1970s due to the exposure to fluoride from other sources” (such as toothpaste).

Worldwide, there is a trend to discontinue using fluoride in water.

Belgium has banned the sale of tablets, drops and chewing gum containing fluoride and the city of Basle in Switzerland has stopped fluoridating water because it found there was no evidence that rates of tooth decay were any lower than in non-fluoridated cites.

In his paper, Dr Diesendorf said there were very low levels of tooth decay in many European countries that were unfluoridated and “negligible difference” in tooth decay between 42 fluoridated and 42 unfluoridated US cities studied by the National Institute of Dental Research.

Also, he said, previous studies comparing tooth decay rates were unfair as they compared fluoridated cities with unfluoridated rural areas, which didn’t take into consideration dietary or lifestyle differences.

Doug Everingham, federal health minister from 1972-75, is an adviser to Professionals Against Water Fluoridation, which represents 1500 doctors, dentists and scientists.

“In many cases, fluoride studies don’t compare like with like,” he said.

“More serious damage takes longer than a few years to identify because it’s increasing incidence of things like bone fractures. They will appear only in long-range studies.

“Comparing Queensland with the average of Australia is not a fair comparison because of many factors such as a higher Aboriginal population than other states.

“We should not be giving shotgun therapy to the whole population. Fluoride is much more effective if applied topically to the teeth. It has no benefit being swallowed.”