Summary

During the first half of the 20 th Century, a lower prevalence of dental caries (tooth decay) was observed among areas of the United States where drinking water supplies provided fluoride at a concentration at approximately 1 part per million (ppm). Controlled studies across the world have demonstrated a protective effect on caries prevalence by adding fluoride to municipal water supplies (fluoridation) to provide a concentration of approximately 1 ppm; especially among people who liven in fluoridated areas since birth.

With increased access to fluoride toothpastes and over all better oral hygiene practices, the importance of fluoride as a preventative measure against dental caries has lessened, however is still considered significant by Australian health authorities such as the National Health and Medical Research Council as well as international bodies such as the World Health Organization.

Many groups and individuals have objected to fluoridation over the years, claiming that it may be harmful and increase the risk of bone cancer, osteoporosis as well as a host of other serious medical complications. Most good evidence thus far suggests that there is no significant correlation between fluoridation and these diseases, though more research should be conducted to validate fluoridations safety.

Fluoridation opponents often also argue that fluoridation is an unethical type of mass medication against the populations will, though proponents argue that allowing the lay public to decide whether or not to accept fluoridation s a valid safe and preventative measure is even more unethical.

Whether or not to fluoridate water supplies is a matter decided upon by local governments, and most major cities across the country have decided to implement fluoridation s a public health measure, with the exception of Brisbane, who considers the benefit to be insignificant.

There is no simple solution to these very controversial arguments, as supporting either stance will inevitably result in considerable criticism. Rather than attempt to decide whether or not fluoridation is an appropriate measure to be implemented by Brisbane and other areas across the country, it is out view that such a decision would be best made by more authoritative government bodies such as the NHMRC than to be decided upon by local councils.

Dental Caries

Dental caries is considered the most prevalent health condition affecting Australians of all ages, and is associated with a number of problematic clinical complications; (Mathers et al 1999) especially amongst the elderly including difficulties with chewing and swallowing (dysphagia) which can lead to malnourishment (Daly et al 2003) as well as speech and respiratory complications (such as pneumonia) as a result of aspiration. (Morris 2006)

Fluoridation

Fluoride is a mineral which occurs naturally in most water supplies, though at varying concentrations throughout the world. During the early half of the 20 th century, it was discovered that throughout certain areas such as Coloarado and Texas , it was common to find people with an unusual staining of the teeth, often referred to as ‘Colorado Brown Stain' or ‘Texas Teeth'. Researchers also found that the prevalence of dental caries was very low among areas where people exhibited this staining, which was later identified as being caused by naturally higher levels of fluoride in those areas drinking water supplies.

After much epidemiological research, it was discovered that the ideal and safe water fluoride concentration needed to protect against dental caries was approximately 1 part per million (ppm). Starting with Grand Rapids Michigan in 1945, several controlled studies were then conducted across the United States (and eventually throughout other areas of the world) too see whether adding fluoride to public drinking supplies (fluoridation) to achieve a concentration of 1 ppm would significantly decrease the prevalence of dental carries in those areas. It did. Additional cities across the United States and Canada began fluoridation, which lead to a significant reduction in the rate of dental caries in fluoridated areas. Fluoridation was then introduced Hong Kong , Singapore , Ireland and some parts of the United Kingdom , though was never adopted by most European countries. (NHMRC 1991)

Fluoridation in Australia

Fluoridation was first introduced in Australia in Tasmania in 1953, and by 1977, approximately two thirds of the Australian populations drinking water had been fluoridated, with studies finding a consistently lower prevalence of dental caries among fluoridated populations.(Armfielf 2005) .

That number has remained fairly constant to this day, though the majority of areas receiving fluoridated water are urban populations, with most non-fluoridated communities being in rural locations. (Spencer et al 1996) The major exception of course is Brisbane , which is the only major city to reject water fluoridation, and consequently has a higher prevalence of caries than nearby fluoridated Townsville. ( McEniery & Davies 1979, Slade et al 1996)

In areas where fluoridation occurs, continuous to weekly assessments must be carried out in order to assure concentrations remain within acceptable limits, (which are lower among hotter areas to take greater fluid consumption into account) as concentrations in excess of 1.5ppm can cause dental fluorosis (staining of the teeth) whilst concentrations over 4ppm can cause skeletal fluorosis. (NHMRC 2004)

Controversy

In certain areas of the world, (including Australia ) public water fluoridation has become one of the most controversial and debated public health topics of the last 50 years, with many groups and individuals protesting against fluoridation for a plethora of reasons. Other than opposing fluoridation, there seems to be no official uniform position taken by antifluoridationists; many citing all sorts of reasons ranging from the potentially plausible, to the completely absurd; often referred to as “poison mongering” by others in the scientific community. (Sprague & Bernhardt 1993) For example, some antifluoridationists have tried to scare people into opposing fluoridation by referring to it as “rat poison” (Barrett 1978) and even claiming communist conspiracy theories of governments using it to sedate the population in order to exert mind control over them. (Wrapson 2005)

Antifluoridationists who cite actual scientific studies are often found to be biased, using selective citation, rather than systematically reviewing all the available evidence. (Spencer 1998) Because of the diverse range of reasons that various antifluoridation individuals and groups have cited for opposing fluoridation, it would be impossible to address every single one of them, though the most common and less irrational arguments include a) that fluoride may be harmful or poisonous. b) that the benefits of fluoridation are insignificant or unproven, and c) that governmental fortification of drinking water with fluoride is a kind of mass medication which infringes upon an individuals freedom of choice.

Potentially Harmful

There are a plethora of harmful effects which antifluoridationists cite as reasons to oppose fluoridation; so many in fact that it would not be feasible to keep track of them all yet alone address them all as serious concerns. The most common however include dental and skeletal fluososis, hip fractures and cancer. ( Diesendorf et al 1997, Connet 2006)

Dental fluourosis occurs when excess fluoride builds up in tooth enamel, resulting in small white coloured stains which can cause unsightly brown “mottling” if fluoride exposure is excessive; most likely due to regular ingestion of fluoride tooth paste. Dental fluorosis is largely an aesthetic matter, and ordinarily not a significant health concern. (Browne et a l 2005) Skeletal fluorosis may be more problematic, however does not occur in areas where fluoridation is within safe levels. (Kaminsky et al 1990)

Studies have reported conflicting evidence in regards to the association between water fluoridation and hip fracture, with some studies suggesting that higher levels increase the risk, whilst others reported no correlation. (Hillier et al 1996) A meta-analyses on this subject conducted by Jones et al (1997) found that overall, there was no significant association between water fluoridation and risk of osteoporotic fracture.

Some fluoridation opponents have suggested that fluoride is carcinogenic; claims which have been criticized as being based on statistical bias and deliberate exaggeration. (Cook-Mozaffari 1996, Spencer 1998, Pollick 2006) A frequently cited study by fluoridation opponents is the US National Cancer Institutes Surveillance, Epidemiology and End Results (SEER) program which reported a higher in cadence of osteosarcoma (bone cancer) among young males in two fluoridated areas of the United States . (Hoover et al 1991a) Further analysis of the time trends by Hoover et al (1991b) however found that the increased prevalence of osteosarcoma was not related to the time of fluoridation. Moreover, a similar study by Mahoney et al (1991) found no difference in the prevalence of osteosarcoma among any age group between fluoridated and non fluoridated cities in New York State .

This does not necessarily provide conclusive evidence that fluoridation does not increase the risk of osteosarcoma however, as this is a subject which has not been studied very extensively. Additional research is needed, though given there is currently no good evidence to suggest that water fluoridation (in appropriate doses) is harmful, most major health authorities in Australia consider the potential benefit of fluoridation to be significantly worthwhile.

Insignificant Benefit?

There is an abundance of scientific evidence to support the notion that water fluoridation offers both health and cost benefits (NHMRC 1999, McDonagh 2000, Bates 2000, Wright 1999) however the major argument put forth by modern antifluoridation campaigners (in Australia at least) is that the present benefit of fluoridation is relatively insignificant. In Australia , the basis of this argument comes from evidence which has shown that the prevalence of dental caries has been markedly declining over the past few decades, throughout both fluoridated and non-fluoridated areas. In fact, after analyzing all the available, relevant Australian data, the National Health and Medical Council (1991) concluded that whilst water fluoridation was responsible for a 60% reduction in the prevalence of dental caries in 1977, the proportion of reduced caries attributed to fluoridation had dropped to only 40% by 1987. (NHMRC 1991)

Moreover, the overall lower prevalence of dental caries throughout the country was among the primary reasons that Brisbane Council gives for the 1997 Taskforces decision not to fluoridate Brisbane's water supply, stating:

“Opponents pointed to the complex and subjective nature of dental statistics and argued that dental caries rates in Queensland were now so low that percentage reductions, representing a small proportion of a single tooth surface, were inherently unreliable and not statistically significant.”

Despite the benefit of fluoridation being less significant than what it was in previous years, most Australian health authorities consider that the benefit far outweighs the potential risks, with the exception of course of Brisbane 's council. This raises the question of who should be responsible for making a decision such as whether or not to fluoridate local water supplies. The majority of the council committee members who made this decision were not scientists, but laypeople who listened to arguments from both sides, including extremist antifluoridation activists. One could argue that this committee may not have been adequately equipped to interpret the available evidence as well as the NHMRC could.

Further information on this topic has been reviewed by the National Health and Medical Research Council (NHMRC) and can be downloaded here.

Mass Medication

One of the most commonly cited reasons to oppose fluoridation is that it is unethical for a government to subject a population to what is essentially mass medication against their will; the very reason why fluoridation has either not been accepted or has been subsequently discontinued among certain areas of Europe. (Short & Riordan 1996) This debate is riddled with complexities. For example, taking away a persons choice whether to be medicated or not may be considered reasonably unethical, though it could also be argued that allowing them to chose not to be medicated could be more unethical if allowing them that choice meant exposing them to harm, especially if they do not have the necessary capacity to make an a fully informed decision.

Whose Choice should it be?

A common argument made by fluoridation opponents is that fluoride supplements could be purchased and administered among people in non-fluoridated areas, should they chose to accept the positions taken by fluoridation proponents. Fluoridation proponents argue however that laypeople would not possess the necessary educational background to be able to interpret the scientific basis of the fluoridation debate, and consequently be easily swayed by less-than-accurate scientific information they may have encountered in the media which may be potentially misleading. (Campbell et al 2001) Given the often conflicting and poor quality health related information frequently projected by the media and available on the internet (including information on fad diets, dietary supplements, vaccination, food additives and various other myths, hoaxes or poorly understood topics) this may indeed be a reasonable argument.

It could also be argued that local governments may be more likely influenced by political pressure from local communities, and consequently make decisions based more heavily upon gaining approval from voters than on the actual wellbeing of the community they represent. It is unlikely however that an issue such as fluoridation would make the difference between reelection or not for a state or federal government, whose policies would encompass a much broader range of issues.

Professor Tony Adams, (former Chief Medical Officer Australia) recently expressed concern about the decision to fluoridate or not being left to local governments, stating that:

“It is my firm opinion that the whole problem throughout Australia lies with the way the early legislation was framed giving the decision making power to local government. In no other area of public health does this pertain. Imagine the chaos if individual councils could decide if their children should be immunized or if their citizens should be compelled to wear seat belts. Public Health is now a highly specialized scientific discipline requiring expertise found only in State (or Federal) Health Departments.” (Adams 2006)

Conclusion

In conclusion, I do not specifically advocate or condemn either side of the fluoridation debate. My position however is that the decision whether or not to fluoridate water supplies, should be decided by more authoritative state and federal government bodies; such as the NHMRC, who a) would presumably have a greater range of expertise to judge the validity of both arguments, and b) would be under less political pressure to make decisions based more heavily upon popular opinion than scientific evidence.

References

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