Category Archives: city council

Fluoridation & democracy: Open letter to DHB candidate Andrew Buckley

Community water fluoridation looks like becoming a hot topic in October’s elections to District Health Boards. Anti-fluoride candidates should stop preventing open discussion and critique of their unscientific claims.

Legislation transferring fluoridation consultation and decision-making tasks from councils to district health boards (DHBs) will probably be introduced into New Zealand’s parliament next year. Anti-fluoride activists are preparing for this by transferring their attention from councils to District Health Boards. In particular, they are standing candidates for elections to DHBs in October’s elections.


Andrew Buckley is standing for the Waikato District Health Board. He calls for open debate on the fluoridation issue but will not allow any critique of his claims in his web page discussion.

Andrew Buckley is a retired osteopath who is standing for the Waikato DHB. He is making community water fluoridation a central issue of his campaign and presented his views in a blog article – Fluoridation and democracy – and in a press release.

I welcome candidates who make their views clear on issues like this during their campaign where they can be discussed. But the problem with Andrew is that he does not seem to either want to discuss his claims or allow any discussion of them in the comments on his article. I contributed a comment which dealt with his claims point by point but he has not allowed it to appear – despite showing supportive comments from many of the usual anti-fluoride brigade.

This anti-democratic behaviour is ironic given that he was arguing for democracy and open debate on the issue. It is also deplorable that he prevent this open debate during an election campaign where he is making community water fluoridation a central issue.

As he won’t allow proper discussion on his web page I have put my comments into an open letter to Andrew. I, of course, offer him the right of reply here and welcome any contribution he can make to the discussion here.

Hi Andrew,

I welcome your declarations that you are “not pro- or anti-fluoridation as a matter of principle”  and decisions about community water fluoridation (CWF) “simply cannot and should not be made on the basis of hearsay and urban legend.”  However, the claims you make in this article (Fluoridation and democracy“) suggest you may have succumbed a few urban legends and been influenced by hearsay yourself.

Let’s consider some of your claims:

Hamilton City Council’s fluoridation fiasco

You claim the “Hamilton City Council councillors voted unanimously to stop” CWF – but that is just not true.

In June 2013 the council voted 7 to 1 (with several imposed abstentions) to stop CWF. There was public opposition to this decision as it ignored polling and a previous referendum result showing community support for fluoridation. A new referendum held along with the October 2013 local body elections again showed overwhelming public support for CWF and in March 2014 the council voted 9 to 1 in favour of reinstating CWF.

You claim the Hamilton City council “delivered a scathing commentary on the practice of fluoridation.” Could you identify that document and link to it? I am completely unaware of such a document despite having followed the issue closely at the time and having discussed the scientific basis of CWF with several councillors. My impression was that individual councillors were incapable of discussing the issue and, in fact, several councillors were very hostile towards science and scientists and very rude to correspondents as a result. I thought that highly disturbing for councillors in a city which houses several very reputable scientific institutions. But it seemed their stance, and emotive response, had more to do with pre-election political infighting than any appreciation of the science.

Are anti-fluoride claims validated?

You claim “validated claims of the multitude of opponents to water fluoridation [are] not refuted by sound supportive evidence in public debate.” Again not true.

Anti-fluoride activists like Paul Connett, Stan Litras, etc., often claim this but refuse to debate the issue themselves. I had one on-line debate with Paul Connett in 2013/2014 where (I believe) every claim he made was soundly refuted. You can find the record of that debate on my blog (Fluoride debate) or a pdf version of Fluoride Debate  from my publications on ResearchGate . This is quite substantial and covers most issues that are raised by opponents of CWF.

The claims made by opponents of CWF have not been scientifically validated and are often based on misinformation or distortions of the science. It is telling that since my debate with Paul Connett he has simply refused every opportunity I have offered him for a right of reply to my articles where I have critiqued his claims (see for example Misrepresenting fluoride science – an open letter to Paul Connett“). Similarly, Stan Litras has refused my offers of a right of reply in similar situations.

What about this “multitude?”

You are incorrect in using the word “multitude” as recent referenda have shown in New Zealand. This was confirmed in more detail by the NZ oral health survey as reported in this paper:

Whyman, R. A., Mahoney, E. K., & Børsting, T. (2015). Community water fluoridation: attitudes and opinions from the New Zealand Oral Health Survey. Australian and New Zealand Journal of Public Health.

I discussed date from this paper in my article Anti-fluoride propagandists get creative with statistics. The graph below summarises the data:

While support for CWF may not appear as massive as recent referenda results show (which don’t record the undecided), the fact that only about 10% of people are strongly opposed (and another 5% somewhat opposed) to CWF in the survey. This does suggest your use of the word “multitude” is an exaggeration.

The opponents of CWF may be very organised and vocal (a fact which has led councils to see the fluoridation issue as a poisoned chalice) but they basically represent the minority ideological and commercial interests of the alternative health industry – which in many cases funds their work and give avenues for their propaganda.

WHO data misrepresented

You claim “according to the World Health Organisation, [there is] an equal reduction of dental caries in countries throughout Europe, irrespective of whether there is water fluoridation or not” is just not true. You have blindly accepted a popular anti-fluoride urban legend.

In fact, the WHO data show different reductions of dental caries for different countries. The reductions are just not equal. Here is the graph that anti-fluoride activists often use to promote this urban legend:

Slide from Paul Connett’s 2016 New Zealand presentation

There is actually very little data for each country in this graphic (hence the predominance of straight lines). The bigger problem is that no sensible comparison can be made between countries without taking into account the multitude of factors which influence tooth decay and which vary from country to country and year to year. Surely that is obvious?The more sensible and scientifically accepted approach is to compare fluoridated and unfluoridated areas within countries. I discussed this in my article

The more sensible and scientifically accepted approach is to compare fluoridated and unfluoridated areas within countries. I discussed this in my article Misrepresenting fluoride science – an open letter to Paul Connett and illustrated it with the WHO data for Ireland where fluoridated and unfluoridated areas are compared:

People like Paul Connett and his followers promote this urban legend again and again – despite having been shown why it is wrong (for example in my debate with Connett). They are knowingly promoting a distortion of the facts.

CWF a “medicine?”

You ask “Why was fluoride removed from the medicines list . . ?” but CWF was never on a “medicines list” as you would be aware if you had read the High Court ruling in the case brought by the “natural”/alternative health industry lobby group New Health NZ against the South Taranaki District Council.

I refer to this in my article Corporate backers of anti-fluoride movement lose in NZ High Court but you could also read Justice Hansen’s  judgment. This was confirmed in Justice Collin’s ruling on the subsequent appeal (see Another legal defeat for NZ anti-fluoridation activists).

The concentrations of fluoride used in CWF are below that required for listing. As Justice Collins determined:

“when fluoride is added to domestic water supplies within the maximum allowable concentration of 1.5 mg/l the concentration of fluoride in domestic water supplies will be well below the concentration threshold required for fluoride to be a medicine in Schedule 1 of the Regulations.”


“ . . fluoride would be a medicine under the Act if it was added to domestic water supplies in concentrations of 10 mg/l or more.”

The only change to regulations was to introduce a clause clarifying that when chemicals like sodium fluoride, fluorosilicic acid or sodium fluorosilicate are used for CWF they are not considered a medicine. A clarification, not a change.

Why transfer decision and consultation on CWF to DHBs?

You ask why the Minister of health has “decided to take the decision away from local authorities and give it to DHBs to decide?”

As you are a candidate for election to a  DHB you have a responsibility to consult the official documents outlining reasons for the proposed changes. I suggest you read Proposed legislative changes: decision-making on the fluoridation of drinking-water supplies,  Transferring decision-making on the fluoridation of drinking-water from local authorities to district health boards the cabinet paper Decision-making on the fluoridation of drinking-water supplies).

I also suggest you refer to discussions at the Local Government NZ conferences and individual council statements requesting that central government take responsibility for CWF decisions and consultations away from councils. As they have often argued, they do not have the expertise to consider the science involved and feel that they are unfairly exposed to a highly organised minority of ideologically and commercially motivated activists.

Questions for you, Andrew

Do you think a body like the elected DHB or local body councils are the appropriate place to make decisions about the science of health issues like CWF? After all, they do not have the expertise and surely such scientific decisions are not made by the board on other health issues relevant to all the procedures carried out in a hospital. Don’t you think that DHBs and Councils should instead rely on the best up-to-date reviews of the science by a body like the Royal Society of NZ?For example:

For example:

Eason, C., & Elwood, JM. Seymour, Thomson, WM. Wilson, N. Prendergast, K. (2014). Health effects of water fluoridation : A review of the scientific evidence.

Surely the task for board member on this issue is to receive such up-to-date reviews, together with data from staff on the oral health issues in the area and the feasibility and likely efficacy of CWF. On top of that, they should take into account the balanced views of the community – using polls or referenda. This should then allow them to make an informed decision about any proposal for or against CWF in their region.

Getting bogged down with the activist claims and counter claims and their propaganda based on misinformation and distortions of the science (as happened initially with the Hamilton City Council) is certainly not a responsible approach.

Andrew, you criticised the democratic processes of the DHB for which you are standing. I cannot judge if your complaints are sincere as I have not see the full picture. But I certainly support your conclusion about this issue:

“I believe we must follow democratic process and proper debate.”

So, why have you denied the democratic process with your blog article Fluoridation and democracy? You did not allow my comment, which covered the areas above, while at the same time allowing comments from known anti-fluoride activists slavishly praising you for your article?

Does this illustrate the sort of rejection of open and democratic discussion you will follow if you are elected?

I believe voters have a right to know how you have purposely acted to prevent open discussion while hypocritically calling for it.

Surely that is a reason not to vote for you in the October elections?

Finally, Andrew, I offer you a right of reply to my open letter. I am willing to post a reply for you here. After all, I do support open discussion of the CWF issue and, particularly, I am keen that these “urban legends” and “hearsay” be properly debunked and their promoters exposed.

I look forward to a fruitful good-faith discussion.

Kind regards,

Ken Perrott

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New review shows clear economic benefits from community water fluoridation


The NZ Ministry of Health has released a new review of the benefits and costs of water fluoridation in New Zealand.* Unlike most reviews I have discussed here dealing with the scientific aspects, the authors of this review say:

“we take an economist’s perspective; we look at the national cost-effectiveness and cost-benefit of fluoridation, and comment briefly on disparities.”

This perspective is, of course, important to the Ministry of Health which must invest its resources efficiently. These considerations were the prime reason the Ministry commissioned the review from the Sapere Research Group.

Readers who want to read the full report (78 pages) can download it from the link – Review of the Benefits and Costs of Water Fluoridation in New Zealand (pdf, 818 KB).

Strong evidence for benefits

The review points out that oral health is still a major issue for New Zealand. Despite considerable improvement over the last 20 to 30 years, “New Zealand remains a relatively high-caries population:”

“The ‘burden’ of the disease from dental decay is equivalent to three-quarters that of prostate cancer, and two-fifths that of breast cancer in New Zealand.”

It finds strong evidence for the benefits of community water fluoridation (CWF):

“A large body of epidemiological evidence over 60 years, including thorough systematic reviews, confirms water fluoridation prevents and reduces dental decay across the lifespan. The evidence for this benefit is found in numerous New Zealand and international studies and reports.”

Its estimates of the benefits of CWF include:

  • “In children and adolescents, a 40 percent lower lifetime incidence of dental decay (on average) for those living in areas with water fluoridation.”
  • “For adults, a 21 percent reduction in dental decay for those aged 18 to 44 years and a 30 percent reduction for those aged 45+ (as measured by tooth surfaces affected).”
  • “48 percent reduction in hospital admissions for treatment of tooth decay, for children up the age of four years.”

The review expresses this cost-saving in material terms:

“We estimate the 20-year discounted net saving of water fluoridation to be $334 per person, made up of $42 for the cost of fluoridation and $376 savings in reduced dental care. In short, there is a 9 times payoff; adjusting the discount rate from 3.5 percent to 8 percent results in a 7 times payoff.”

This estimate is “robust to significant changes in assumptions.” In fact, their “assumptions around dental costs avoided are likely to be at the lower end of what patients face.”

Quality of life benefits

Not surprisingly the review finds significant benefits of CWF to the quality of life estimates.  Interestingly, it makes the point that while most other health interventions require net health spending, the CWF benefits to quality of life arise from net cost-saving because the savings from reduced need for dental treatments are far greater than the costs of fluoridation.

I can understand the need for economists to quantify the quality of life returns on investment but can not, for the life of me, understand how they can take into account the pain and misery of children who suffer from poor dental health. The review does mention an Oral Health Impact profile which attempts to measure “patient discontent from pain, dry mouth and chewing problems.” But I suspect this goes only a short way to quantifying the personal and subjective problems arising from poor dental health.

In particular, I am thinking of the psychological and physical medium and long-term effects. Poor dental health negatively impacts the child’s schooling and must contribute to learning difficulties. This, in turn, will mean childhood poor dental health reduces a person’s future prospects in employment, adult education, social and personal relationships and general happiness.


The benefits of CWF are clear when considered in financial and economic terms and this new review presents these in a clear and convincing way. It will have an important  influence on the decision makers in the Ministry of Health, parliament and the government – especially as they discuss the new legislation required for the transfer of decision-making on fluoridation from councils to district health boards. But there are also personal and subjective benefits which are much harder to quantify to the satisfaction of economists and other bean counters. In the end, those personal and subjective benefits must bring a positive economic return to society as a whole, as well as the individual. If anything, decision makers and politicians should see that the case for CWF is even stronger than that made by the economic considerations in the review.

*Note: The Cabinet papers on the assessment of benefits from fluoridation and the upcoming legislative changes required to transfer decisions to District Health Board have also been released. These papers are very interesting and give an idea of the different factors the government has considered and the likely way the new legislation will go. I recommend any readers searching for more details on this to download the papers from this link:


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Fluoridation: One small step sideways?

elephant in room

Fluoridation. Let’s not ignore the elephant in the room – the need to separate scientific review from community consultation.

Most health officials and science-minded people welcomed the recent announcement of the government’s plan to transfer decisions on water fluoridation from local councils to district health boards (see Fluoridation decisions to be made by District Health Boards). But the welcome was, in most cases, luke warm. The health and scientific community would probably have preferred that central government take on that responsibility itself. Given that District Health Boards employ staff with much more scientific and health expertise than councils the decision was seen as one small step forward – by a government too timid and politically sensitive to local backlash to “go the whole hog.” But I believe this step ignores the elephant in the room – the need to separate the review of the science from political considerations such as community consultation.

On the other hand, anti-fluoride campaigners have presented the decision as a giant step backwards – at least in their public announcements and campaigns. But their disingenuous claims (describing the step as introducing mandatory fluoridation and removing democratic consultation) suggest this has more to do with scaremongering and rallying of the troops. In reality, they probably welcome the announcement of the plans as providing them yet another chance to deluge the public and politicians with their misinformation and scare stories.

I fear that the government’s moves may turn out to be only one step sideways – although the required legislative process does provide possibilities to make changes that clearly separate scientific consultation from community consultation. That would be a step forward

A small step sideways

Simply transferring the hysterical discussions from elected local councils to elected district health boards will provide the same level of access by ideologically and commercially motivated campaigners and their misinformation. In practice, the elected members of health boards may suffer the same degree of scientific ignorance, ideological biases and hubris amply demonstrated by local councils in the past.

Anti-fluoride campaigners recognise this. They already have supporters on some health boards and are consciously planning to increase their numbers with upcoming local body elections.

Jane Clifton recognised that this sideways step is the most likely outcome in her recent NZ Listener column (subscription required):

“Finally rolling up its sleeves to sort out this nonsense once and for all the Government has  . . .  relocated the decision with district health boards. DHB members are no less subject to fearsome lobbying than councils, so this major public health issue will remain the push-me, pull-you of unqualified, internet-schooled amateur lobbyists and ill-equipped local politicians.”

She says controversies like this are “beyond” councils as demonstrated by the “wondrous variety in their deliberations over fluoridation.”

A real step forward possible

According to the Ministry of Health, the government’s plans require an amendment to the New Zealand Public Health and Disability Act 2000. Page 19 of this act has the following section describing a public health advisory committee:

14 Public health advisory committee

(1) The national advisory committee on health and disability must establish a committee called the public health advisory committee to provide independent advice to the Minister and to the national advisory committee on health and disability on the following matters:
(a) public health issues, including factors underlying the health of people and communities:
(b) the promotion of public health:
(c) the monitoring of public health:
(d) any other matters the national advisory committee on health and disability specifies by notice to the committee.
(2) The advice given by the public health advisory committee is to be formulated after consultation by the committee with any interested organisation or individual that the committee considers appropriate.
(3) The Minister must make publicly available, and present to the House of Representatives, a copy of any advice given by the public health advisory committee.”

I think this advisory committee should be given responsibility for the  overseeing and regular review of the science around community water fluoridation. It could do this by commissioning bodies like the Royal Society of NZ and the Office of the PM’s Chief Scientific Advisor in the same way the Auckland Council on behalf of several local Councils did last year to produce the report Health effects of water fluoridation : A review of the scientific evidence (Eason et al., 2014). Maybe an approach similar to the previous National Fluoridation Information Service, which continually reviewed the literature, could be used. Or maybe such scientific consultation could be tailored to fit the specific situation taking into account any movement in the science and public concern.

Clause 2 above enables consultation with “any interested organisation or individual that the committee considers appropriate.” That would give scope for the credible serious opponents to the currently accepted science but, hopefully, would exclude (or reduce the significance of) the  mindless political campaigner and form letters in submissions.

Yes, the anti-fluoride campaigners would moan about the requirement that submitters be “appropriate” – but the honest ones should welcome the chance to present their scientific claims to a scientifically credible body.

Ideally, then, legislation could provide that scientific consideration is separated from the community consultation when fluoridation of a community is considered. It could make clear that the elected district health boards should not consider the science – that they are not the appropriate body for this. Their role should be to make recommendations after consideration from their staff on the oral health of a community and the need and practical possibility for community water fluoridation.  The board would also have a responsibility to consult the community to determine if fluoridation proposals are supported.

But, please, don’t let such elected boards become bogged down with sifting through piles of submitted misinformation about the science as councils have been. Otherwise, we will just see a future demand, this time from DHBs, for central government to take responsibility for the issue.

Deja vu!


At the moment, we are unclear how the new legislation will pan out. Anti-fluoride campaigners are taking advantage of  the current situation to scaremonger (both about fluoridation and about democracy in general) and spread misinformation. They are making the most of this – and probably enjoying the opportunity as these sort of campaigners recognise that the campaign itself brings more psychological  benefits than the actual decisions.

But the drafting and consideration of this new legislation provide opportunities to turn what could be just a small step sideways into an actual step forward. This could be the time to attempt a separation of scientific considerations and reviews from community consultations.

Perhaps the health and scientific communities could learn a little from the anti-fluoride campaigners activity though. Rather than allowing such campaigners to bombard our lawmakers with their misinformation without challenge, as is currently happening, perhaps there is some scope for sensible lobbying to strengthen the legislation by clarifying that scientific considerations must take place at the central government level and be separated from local consultations.

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Onehunga and the “fluoride-free” myth

Onehunga Aquifer optimised

An aerial view of the Onehunga Water Treatment Plant

Recently I discussed the fluoridation issue with a self-diagnosed sufferer from fluoride sensitivity. He claimed to have irritable bowel syndrome (IBS) brought on by fluoride in drinking water. His doctor didn’t believe him but he knew better – every time he left his hometown (which is unfluoridated) for fluoridated areas his IBS returned. He assured me that the water in his city is “fluoride-free.”

I checked the published data for his city and found the natural levels of fluoride in the tap water is 0.4 ppm – not too much less than the recommended 0.7 ppm where community water fluoridation is used. He didn’t respond to my comment passing on this information – maybe it brought on an attack of IBS as stress is one of the known factors causing this.

This issue came up again at a recent Auckland City Council meeting which considered a request for fluoridation of the Onehunga water supply. Unlike most of Auckland Onehunga’s water is pumped from the Onehunga springs and is not fluoridated. In fact, a referendum in 2001 voted against a proposal to fluoridate.

But what struck me is the argument presented by one councillor that some resident of Onehunga moved there because the water is “fluoride-free” and it would violate their rights if the water supply is now fluoridated. That seems a very poor argument as anyone with a hangup about fluoride can buy and use a cheap water filter – far cheaper than shifting house. But the claim that Onehunga’s water is “fluoride-free” motivated me to check out the published data for fluoride in the Onehunga water.

This graph summarises the data from reports covering the years 2010 – 2014 (a single report covered 2011-2012):

So, Onehunga water is not “fluoride-free.” The average concentration is about 0.2 ppm (not too unusual for ground-water sources in New Zealand) but the actual concentrations can vary a lot. Customers would have occasionally been drinking water with a concentration as high as 0.9 or 1.1 ppm F during that time period.

Surely this would occasionally send any fluoride sensitive person into a bout of IBS, skin rash, or one of the myriads of other symptoms propagandists against community water fluoridation claim. Or perhaps only if they had been told about the high concentrations (see Fluoride sensitivity – all in the mind?).

Fluorine is the 13th most common element in the earth’s crust so it is inevitable that our food and drink contain traces derived from natural sources. In the real world, there is no such thing as “fluoride-free.”

Note: I don’t know if such variation is common with underground freshwater sources. The Onehunga aquifer  derives from rainwater soaking through lava flows around One Tree Hill. It could well be prone influences from historical industrial or other sources in the locality. Apparently it has high nitrogen levels and may also be influenced by broken sewer pipes.


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Responding to Tracey Brown on fluoridation

CWFwaterI appreciate Tracey Brown, Director of Sense About Science, taking the time to respond to some of the comments in my article The ugly truth about critics of “the ugly truth” in science (see “The ugly truth” – Tracey Brown ticks me off). Despite apparent differences I think Tracey and I are singing from the same hymn sheet regarding the need to confront assumptions and check the evidence supporting common claims. That was the message from her lecture and I simply expanded this to include claims of the sort Tracey herself was making.

An apology

First, I must apologise for implying Tracey relied only on the reading of the two papers that were cited to me. I of course have no idea what other reading she has done on the subject – although some of her comments did reflect the views of Peckham, a well-known anti-fluoride activist, as expressed in his misleading paper Peckham (2012).

I also did not know for sure she had based her comments on “inadequate knowledge – claims from anti-fluoride campaigners she uncritically accepted.” That should have been expressed as my view, my conclusion, drawn from her lecture – rather than a statement of fact.

I did say “even scientists, and pro-science people, can suffer from confirmation bias – just like anyone else. They can sometimes adopt a partisan position which restricts them to considering only the misinformation and distortions peddled by anti-science campaigners.” However, I was simply presenting that as  a general problem – not accusing her specifically of this. We should be able to raise these possibilities without being accused of “rudeness” or “brittleness.” This oversensitivity can be an obstacle to the necessary tasks of demanding evidence for the claims being made by anyone.

The fluoridation issue

I don’t, for a minute, think Tracey has jumped on the anti-fluoride bandwagon. But I am concerned that she seems, at this stage, to have uncritically accepted some of the claims made by people like Peckham and Connett.

Tracey’s understanding of community water fluoridation (CWF) is important. A she said in her lecture, “members of the public have asked “Sense About Science” about it.” Her organisation needs to be able to correct misunderstandings and provide an objective summary of CWF. (In this respect Sense About Science is a similar position to Making Sense of Fluoride, a group I belong to). I think, at the moment, Tracey’s comments indicate her organisation’s advice on CWF could be misleading.

Tracey’s response struck me a being largely defensive – objecting to the style of some of my specific comments rather discussing the evidence for or against CWF or its handling by health authorities and decision makers. As it stands she still appears to adhere to the claims made in her lecture which, I think, are just wrong. So, it is worth expanding on some of the comments I have already made.

Is there really no critical assessment of the evidence for CWF?

It is ironic that Tracey uses CWF as an example where evidence has not been questioned. She even says that “governments went about fluoridation in the 50s by stealth, without discussion which caused a backlash.”

But the facts are that in most jurisdictions the decisions on CWF are usually made by local bodies and water companies, not governments. These decisions usually involve consultations and often very contentious debates.  Unlike many other health measures, CWF has been countered from its very beginnings by protests and representations. Although this has usually been ideologically driven and sometimes, but not always, extreme, such opposition has guaranteed a high level of discussion, consultation and scrutiny of the evidence.

That continues to the present day. In my own city (Hamilton, New Zealand) pressure from activists to cease CWF lead to a limited consultation by the council in 2013, and a decision to stop fluoridating. Citizens, many of them quite knowledgeable on the subject, reacted because they felt they had not been properly consulted or listened to and the council had ignored previous referendums and their own polling data. A new referendum showed overwhelming support and subsequently  the council reversed their decision and CWF returned to our city in 2014.

Actually, this illustrates two features which must be taken into account in our defence or criticism of social health policies.

  1. Often the central issue is one of values – even the conflict between a social approach or a libertarian one. Decision-makers should take account of such values in their community as they may be more relevant than the science.
  2. Decision-makers often just do not have the skills to judge scientific evidence. This was particularly true for the Hamilton City Council which was effectively swamped by anti-fluoride activists promoting misinformation and distortion.

For many people involved in this process, and many citizens, CWF has been revisited so many times, the evidence scrutinised and criticised so many times, there is indeed a backlash. Citizens are not happy about their local bodies spending so much time and money on repetitive consultation and even react negatively to new referenda. New Zealand local bodies now wish to unload the whole issue onto Central government arguing, quite legitimately, they do not have the expertise to make such decisions. They have had a gutsful of the issue.

Benefits of opposition

This continual consultation and rehashing of the evidence has produced some positive outcomes – the anti-fluoride activity has a silver lining. The Royal Society of NZ, together with the Office of the PM’s Chief Scientific advisor produced a review updating the evidence relevant to the efficacy and safety of CWF to the middle of 2014. The citation is:

Eason, C., & Elwood, JM. Seymour, Thomson, WM. Wilson, N. Prendergast, K. (2014). Health effects of water fluoridation: A review of the scientific evidence.

This was partly financed by local bodies who felt thoroughly confused by the competing claims. I suggest Sense About Science people read this document, and others, in their efforts to get up to speed on CWF.

Not only does NZ now have an up-to-date review of CWF we also have several High Court decisions which put to rest some of the claims made by activists. Poetic justice perhaps – as funding  from the “natural”/alternative health industry has actually produced scientific and legal judgements supporting CWF! The opposite of what they intended.

Setting “optimum” levels

Tracey said in her response:

“I stated, briefly, that the one part per million figure originates from those old studies. Other parts of the world have rejected it in favour of different concentrations. My reading of the subsequent research on concentrations was that it was not possible to come up with a clear case for one part per million, as opposed to say 0.7 as used elsewhere, and that although the need for controls is better understood and sometimes applied, the multiple and variable sources of other contributors to dental health have made it harder to get a signal from the noise. In the lecture, I pointed out that it’s very difficult to control and measure the dose that people actually get from water. It’s not clear whether you disagree with this.”

Her original comment on “old studies” still stands. As I said before, standards are set according to the studies available at the time – this does not mean they are not revisited or changes as new studies become available. This has, in fact, happened with CWF and it is misleading to imply otherwise.

I don’t think it is a matter of “rejecting” the research. Health authorities and decision makers in each country make decisions about “optimum” levels taking into account their own specific situations, dietary intake, drinking water consumption, etc. Counties don’t “reject” decisions of other countries.

Of course it is hard to control and measure the “dose”, or intake – but that is true for any beneficial element – most of which have upper and lower bounds for recommended intake. Dietary consumption is hardly an exact science – one should not be concerned about the 0.7 or 1 ppm difference. Why should fluoride present a special problem?

Personally, I see talk about “dose” as another misleading argument promoted by anti-fluoride campaigners. Firstly, because of the implication such accuracy is required and secondly because it is painting fluoride out to be in the same class as a very active and possibly toxic drug requiring accurate control – which it isn’t. Really, fluoride is in the same class as sodium, potassium, phosphorus, magnesium and selenium. It is not a drug.

Trends of declining dental decay

No one claims CWF is a magic bullet, or that it is the only factor behind improving oral health. Yet the graphic Tracey used is promoted constantly by campaigners to “prove” CWF is ineffective by implying health authorities see fluoride as the only factor involved.  The graphic “proves” nothing except that oral health has improved over the years.

In my article I assumed Tracey used the image from Cheng et al (2007). In fact, her comments on Austria introducing gobstoppers suggest she probably used the one below from Peckham (2012). There are warning signs there as the citation was a personal communication from Chris Neurath – an activist and “research director” in the management of Paul Connett’s Fluoride Action Network. Even the journal citation should ring bells as Fluoride is a poor quality journal effectively managed by the anti-fluoride community.

Peckham image

And, as I pointed out in my original article, these images avoid showing the WHO data within countries – which do show that CWF is effective. It is extremely naive, and misleading, to suggest that the WHO data shows that it is not effective.

I am seriously concerned that inadequate review of the scientific literature will lead to Sense About Science promoting this misleading graphic in its response to public requests for information.

Real world problems for public discussion of evidence

Institutional cultures often restrict the ability of staff to comment publicly. This may be expressed as a condition of employment or it may just be informal discouragement. On the fluoridation issue, it may just be a matter of institutions preventing staff from participating in the “street-fighting” nature of many of the public discussions. In fact, some local institutions have said they are not ready to expose their staff to the threats and abuse which are often part of these public discussions. It is a health and safety issue for them.

Consequently, these discussions are often handled better by non-institutional “activist” groups like Sense About Science. The group Making Sense of Fluoride (MSoF)is effectively a sister group to Sense About Science, but concentrating on the scientific and ethical issues around community water fluoridation. It was formed precisely because institutions like District Health Boards are not able to take part fully in the public debate. Many MSoF people are not limited by institutional requirements.

Incidentally, institutional restrictions are another reason many people who discuss scientific issues publicly are retired. Such retirees often have the background knowledge and research skills necessary for this discussion but no restriction on what they can say, and where.

Tactical approaches are also important. Very often the public is not interested in the scientific details and qualifications which should be attached to evidential claims. They are often happy to leave such discussion to the “boffins.” Scientific debates may be suitable for some fora but can be a real turn off in referendums. Institutional decisions to forgo scientific debate and detailed qualifications may be completely correct in such situations.

The issue of making disagreements like this public (in the same way Tracey suggests health authorities may not be completely open about the contradictory evidence) is a real one for me with this and my previous post. I had to consider tactical questions. Tracey’s comments on CWF may have been buried within her lecture and not noticed by anti-fluoride activists who just love to publicise and promote such statements. My criticism has now brought them to the attention of the anti-fluoride community. I have handed them a bit of juicy propaganda.

However, my motive is promotion of integrity in science and the need to back up claims with evidence. This is more important to me than a specific campaign of support for CWF. Tracey provided an example which illustrates my concern – so why should I not comment on it?

The public discussion of science, which was the subject of Tracey’s lecture, is not simple and we should not neglect the social and psychological research about public opinion and the way to communicate with the public.


I am grateful to Tracey for responding to my article and wish her and Sense About Science the best in updating their knowledge on CWF.

I am a little disappointed her response was defensive and did not involve an in-depth discussion of CWF. This is probably natural, but it is important that groups like Sense About Science and Making Sense of Fluoride not ignore such challenges. It is also important for such groups to be ready to update their knowledge and opinions on issues when required.

In her article Can you handle the truth? Some ugly facts in science and sensibility introducing her lecture Tracey said:

“The ugly truth is that all of us – however informed, however good our intentions – end up letting things slide once in a while. We overlook, overstate or understate the evidence behind research, claims, or policies, for a number of reasons.”

So true – and something we should continually come back to.

I think Tracey was guilty of this in her claims about CWF. Granted, these were only a small part of her lecture. But to anyone with sufficient knowledge to see her mistakes the claims about CWF did detract from the authenticity of the other claims she made.

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Elected officials must ignore activists and listen to own voters


Karen Williams Seel, a member of the county board of commissioners in Pinellas County, Fla.

A recent US blog article made some very pertinent points about the role of elected officials, such a local body councillors, on important social health issues like fluoridation.  These officials have a responsibilty to avoid pressure from misinfomred activists and must instead  listen to their constituents.

Karen Williams Seel, who wrote the article Fluoridation: Elected officials have a critical duty is a member of the county board of commissioners in Pinellas County, Fla., USA. Three years ago, the board voted 4-3 to stop fluoridating its water supply but reversed that decision in 2012 after voters defeated two incumbent commissioners who had voted against fluoridation. In both instances, Seel voted in favor of fluoridation.

She wrote:

“As Americans increasingly seek health information online, elected officials and other policymakers need to recognize that anti-fluoride activists have created a web-based panoply of false fears. For many fluoride critics, these online messages are the source of their concerns. This spring, for instance, a New York resident wrote a letter to his local newspaper, saying he “was surfing the Web and came across information on water fluoridation and the dangers that lie within this practice.”


“Public officials have a responsibility to listen to their constituents. We also have a duty to not allow false fear to drive public health decisions. We should direct our constituents to reputable websites like these sites. We shouldn’t let “guess what I read on the internet” be the reason that we abandon a proven, safe practice like water fluoridation.”

Rotorua District Councillors should take Seel’s points on board as they confront their own decisions about Rotorua’s fluoridation and how to consult citizens on it (see Council votes for referendum on fluoridation).

They should also beware of the”Tribunal” trap the Hamilton City Council fell into which effectively led to them being captured by politically and ideologically motivated anti-fluoridation activists, ignoring the information from scientific and health professionals, and ignoring the views of voters. A mistake which eventually led to pressure for another referendum and a reversal of the council’s faulty decision.

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Fluoridation: emotionally misrepresenting contamination

Another attempt by me to put the issue of contamination of fluoridation chemicals into proper context.

This time I am using data placed on-line by Sapphire Eyes Productions. They produced an emotional anti-fluoridation film Fire Water which relies heavily on the argument that fluoridation chemicals are waste products full of contaminating heavy metals. Trouble is – the data they put on-line does not support the argument – rather it destroys it as it shows that the measured levels of contamination are well below regulated limits.

You can find their data at Raw Fluoridation Chemical Analyses – Freedom of Information – South Australia Water Corp.: FOI Fluoridated Water Analyses for South Australia, 2006 – 2010.

I have extracted the relevant data – from the 16 certificates of analysis for fluoroslicic acid they presented. In the table below I compare the range of contaminant levels with the regulated maximum concentrations for New Zealand (quoted in  NZ Water and Wastes Association Standard for “Water Treatment Grade” fluoride, 1997). As mentioned in previous articles the specific impurity limits are calculated from the maximum acceptable value (MAV) of an element taken from the Drinking-Water Standards for New Zealand 1995. A further safety factor is used as described in the regulations:

“Specific Impurity Limits (SIL) have been calculated based on a maximum dosage (MD) of fluoride ion/litre of water and the maximum acceptable value (MAV) of a parameter taken from the Drinking-Water Standards for New Zealand 1995. The safety factor (SF) used in the calculation should be a minimum of 10, which reflects the view that no more than 10 percent of aMAV should be contributed by a given impurity in a water supply chemical.”

Put simply, the contamination from fluoridation chemicals should contribute less than 10% of the maximum acceptable value in the finished water.

Element Regulated maximum – ppm Range 16 certificates – ppm
Antimony 40 0.005 – <2
Arsenic 132 1.1 – 4.3
Cadmium 40 0 – <2
Chromium 660 0.6 – 7.3
Lead 132 <0.001 – <5
Mercury 26 <0.1 – 7.9
Selenium 132 <0.05 – <2

The data clearly shows that contamination is far lower than the regulated maximum in all the relevant cases. Even for mercury the high top end of the range was for only two samples all others would have contributed less than 10%

And remember less than 10% of the regulated maximum means less than 1% of the maximum acceptable value for drinking water.


So, don’t be taken in next time an anti-fluoridation activist goes on about waste products and contamination – even if they refer to specific analytical data. Insist on looking at the actual data and checking the levels against the regulations. Don’t be fooled by their tendency to flash the data and quickly move on (as they did in the Hamilton Fluoride Tribunal).

Remember, these days analytical methods can be extremely sensitive. Just because we can measure a contaminant concentration does not mean we should be concerned about it. After all, all our foods and drinks, natural or not, will contain almost any element at extremely low concentrations.We should always attempt to put the information into its real context.

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Fluoridation: putting chemical contamination in context

Anti-fluoridation activists often claim fluoridating chemicals used for water treatment are contaminated with heavy metals and radionuclides. I have written about this before in Fluoridation – are we dumping toxic metals into our water supplies?Water treatment chemicals – why pick on fluoride? and Hamilton – the water is the problem, not the fluoride!  The issue was also discussed in my exchange with Paul Connett (see Fluoride debate).

Trouble is, many people have difficulty putting measured levels of contamination into context. After all, if there is a sufficiently sensitive analytical method available just about any contaminant will be detected and measured in our food and water. The important issue is the magnitude of the contamination (which is often natural anyway). That is why measured levels of contaminants must be compared with the maximum allowable values defined in regulations for food and water safety.

I have seen anti-fluoridation activists presenting submissions to councils who will flash on the screen a copy of a certificate of analysis as “evidence” of heavy metal contamination without any reference to the measured values at all! Their logic seems to be that the fact contaminant levels have been measured at all is some sort of “proof” of dangerous contamination.

Arsenic in Hamilton City water

It may help to consider the possible levels of contamination with the contamination from natural sources. In the graph below I have plotted the relative contribution of arsenic from natural and fluoridating chemicals in the treated Hamilton City (NZ) water. Arsenic is commonly mentioned by opponents of fluoridation.


The source water for Hamilton (Waikato River) contains arsenic from natural sources usually 2 or 3 times the maximum acceptable value (MAV) for drinking water (10 ppb As) (McLaren and Kim 1995). (ppb = parts per billion). In the figure the first bar represents river water arsenic content just under 30 ppb. After treatment up to 90% of the arsenic is removed so that it does not exceed the  MAV  (here 3 ppb) – red horizontal line. However, the contribution from fluoridation chemicals used (assuming about 2 ppm As in the FSA – the last batch used in Hamilton had 0.4 ppm As) is miniscule (about 0.01 ppb) compared with that from natural sources. Too small to show in the above graph.

Seems to me rather silly to argue against treating Hamilton water with fluoridating chemicals because they are “contaminated” with arsenic while ignoring the much large contribution of arsenic from the source Waikato River water.

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Fluoridation returns to Hamilton City.


The Hamilton City Council voted this afternoon to recommence fluoridating the city’s water supply

The vote was overwhelming – 9 for, 1 against. The overwhelming support for fluoridation in last year’s referendum was decisive in the decision.

There is a threat to bring legal action against the council – the Deputy Mayor’s comment on this – “Bring it on – a legal decision will decide for the whole country.”

See also:

Fluoride to return to Hamilton’s water supply
Hamilton votes to restart fluoridation
Fluoride back for Hamilton – Council backs the community response

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Fluoridation: Hangout with the University of Waikato

Google-Hangout-Banner-FluorideThe referenda defeat suffered by the Fluoride Free groups campaigning against community water fluoridation does not mean this issue has now been settled. The activist groups insist they will continue their campaign.

Hamilton is still a prime target for them. Despite the 70% support for fluoridation the referendum was not binding. The  new Hamilton City Council still has to vote on whether to re-introduce fluoridation.  So expect to see more campaigning in Hamilton in the near future.

This means Monday’s “hangout” by Waikato University is still going to draw a lot of attention. It’s a chance for interested people to ask questions directly to a panel of academics with expertise in chemistry, fluoride and the fluoridation issue.

This will be a new experience for me – never participated in an on-line “hangout” – and I am intrigued to see how successful this will be for communicating science to the public.

The video will be available on-line afterwards but for anyone wanting to participate here are the details:


Date: Monday 14 October 2013
Time: 12pm – 1pm NZST


On the University of Waikato Fluoridation in Hamilton Hangout website

The video of the live hangout will be embedded on this page 10 minutes before the event, or you can view and ask questions on the Google+ page –

The Hangout page advises:

We’ll be asking your questions live to our expert panel. Tell us what you want to know about fluoridation on Facebook or on Twitter using the hashtag #uowhangout or on our Google + Page via the Hangout Q&A app. Once the hangout has started, you will also be able to ask questions via the comments section on the YouTube live hangout.

New to Google Hangouts? Find out more about Google Hangouts here.

What if I can’t make it?

They will be uploading the complete hangout to their YouTube channel to watch after it ends:

The panel:

See also:

Waikato University Fluoridation in Hamilton Hangout Facebook Event page.
Similar articles on fluoridation
Making sense of fluoride Facebook page
Fluoridate our water Facebook page
New Zealanders for fluoridation Facebook page