Category Archives: New Zealand

An outdated tax anomaly – charitable status of relgion

Here is a New Zealand Kickstarter project well worth supporting – a film which sets out to answer the questions:

  • Why do religions pay few taxes?
  • Why do companies owned by religions also avoid tax?
  • With more non-believers than ever – is this fair?

Pennies from Heaven – A Documentary about religion and tax. by Toby Ricketts — Kickstarter.

The tax-free and rates-free  charitable status of religions in this day and age is an anomaly which will eventually need resolving.  As the proposal says:

Despite this huge rise in the number of non-believers and increased focus on the importance of separation of church and state, most ‘secular’ governments continue to subsidise religious organisations; providing them with broad tax immunity (including any companies or corporations that they own), local rates exemptions and other entitlements. While the public expectation is that all religions are behaving as charities in the traditional sense (working to relieve poverty and advance the public good, etc.), the reality is that some churches are behaving more like corporations; stockpiling cash and buying external investments (putting aside for the moment the mansions, sports cars and diamond rings sported by bishops and ministers). The result of this tax break for the religious is that there is less money for education, healthcare, conservation and other core state functions that would benefit a nation as a whole.”

The problem is highlighted in this report - Religious financial privileges in New Zealand.

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Is anyone listening?


Thanks to: Twitter / SonyKapoor: “Is this mic actually on?” ….

March ’14 – NZ blogs sitemeter ranking


Image Credit: SingleHop

There are now almost 300 blogs on the list, although I am weeding out those which are no longer active or have removed public access to sitemeters. (Let me know if I weed out yours by mistake, or get your stats wrong).

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters.

Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for March 2014. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers.

Meanwhile I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings

Subscribe to NZ blog rankings by Email

Find out how to get Subscription & email updates

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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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Dental fluorosis: badly misrepresented by FANNZ

Ideologically motivated political activists often make extreme claims. Perhaps they feel their claims will never be challenged because they are aimed at their own supporters. Sometimes I think it is because they just don’t get challenged enough by reasonable people.

I have previously shown examples of misrepresentation of science by local anti-fluoride activists (see Fluoride and heart disease – another myth , Anti-fluoridation porkies – Mullinex’s ratsFluoridation: the hip fracture deceptionAnatomy of an anti-fluoridation myth , Fluoridation – the IQ mythActivists peddle chemical misinformation for fluoridation referendaCherry picking fluoridation dataFluoride sensitivity – all in the mind?Fluoridation – topical confusionFluoridation – it does reduce tooth decayFluoridation – are we dumping toxic metals into our water supplies?).

Here’s another blatant example – their misrepresentation of dental fluorosis. In this case it involves knowingly using the wrong photographs while quoting a Ministry of Health (MoH) source on the subject. I have posted below both the official photographs used by the MoH and the photographs they were replaced with in the anti-fluoridation quote. This blatant misrepresentation occurs on the official website of the Fluoride Action Network of NZ (FANNZ).

But first, this is what I wrote about dental fluorosis in my exchange with Paul Connett. The graph illustrates the nature of dental fluorosis observed in New Zealand.

Proponents of fluoridation do acknowledge dental fluorosis in a negative, although minor, aspect of fluoridation.

Opponents of fluoridation will often quote high values of the incidence of fluorosis which ignore the fact that much of it is “questionable” and/or “very mild.” These grades are really only cosmetic and usually can only be detected by a professional. Opponents may also hide the fact that the incidence of fluorosis for children living in fluoridated may often be the same as, or only slightly greater than, the incidence for children living in non-fluoridated areas.

The graphs below shows the situation reported for New Zealand in the 2009 New Zealand Oral health Survey (see Our Oral Health).

Health experts have generally concluded that the apparent rise in the incidence of fluorosis is caused by increases in other forms of fluoride intake, such as from eating toothpaste, and not from fluoridated water.

Ministry of Health version

I am quoting here from the MoH website page - Infant formula and fluoridated water. This is the page FANNZ quoted from

Enamel fluorosis

Tooth enamel fluorosis is one of a range of changes to tooth enamel. Living in an area with fluoridated water can increase the mild white flecks or streaks in the tooth enamel.

The following photos provide examples of normal teeth and the types of mild to moderate diffuse enamel fluorosis that is most commonly associated with water fluoridation. The most recent New Zealand information indicates that about 29 percent of 9-year-old children in Southland who had always received fluoridated water had these changes to the tooth enamel. This level had not changed since several earlier studies undertaken in the 1980s. (Bold my stress)

Normal dental enamel
Mild white spots on teeth – mild diffuse enamel hypoplasia
Mild white spots on teeth – moderate diffuse enamel hypoplasia

Moderate white streaks associated with enamel fluorosis

Other defects on teeth

Severe enamel fluorosis involves brownish defects to the tooth enamel which may also be pitted.

This form of enamel defect is uncommon in New Zealand. The most recent New Zealand information from 9-year-old children in Southland indicates that about 5 percent of children had similar defects.

These defects were just as common in children who had received fluoridated water as non-fluoridated water and the level of these defects had decreased about three fold from about 15 percent of children in the mid-1980s.

FANNZ version

The quote here is from the FANNZ website page Dental health.

Fluoridation causes dental fluorosis

Dental fluorosis is the outward sign that has a child has consumed too much fluoride – it is a bio-marker of over-exposure.  In New Zealand, dental fluorosis statistics are lacking, even though the Ministry of Health acknowledges this condition to be an undisputed side effect of fluoridation.

Very mild fluorosis
 Moderate fluorosis
Severe fluorosis
Severe fluorosis

According to the Ministry of Health*, “The most recent New Zealand information indicates that about 29 percent of 9-year-old children in Southland who had always received fluoridated water had these changes to the tooth enamel. This level had not changed since several earlier studies undertaken in the 1980s.” (Bold my stress).

* Note this link goes only to the MoH front page – not the page from which the quote was taken and which contains the photographs. Now, I wonder why the link isn’t direct?

So a blatant example of misrepresentation. Conscious misrepresentation at that because it involved substitution of the official photos by others. The intention was clearly to make the MoH seem to state that fluoridation causes severe fluorosis when the MoH clearly did not state that.

I really wonder how these people sleep straight in their bed at night.

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Corporate backers of anti-fluoride movement lose in NZ High Court.


Image Credit: 3 News NZ

New Zealand anti-fluoride activists (and their industry backers) suffered a signficant blow with the release of a High Court Judgement on Friday. This Judgement found that all the arguments used by New Health NZ attempting to prevent fluoridation  of the water supplies in Patea and Waverly had failed.

Readers can download this 43 page judgement – I have included the Summary and Conclusions at the end of this post.

Not about the science

Commenters can easily slip into arguments this is a judgement on the scientific merits or problems of fluoridation. It isn’t.  Justice Rodney Hansen says:

[5] It is important to make it clear at the outset that this judgment is not required to pronounce on the merits of fluoridation. The issues I am required to address concern the power of a local body to fluoridate drinking water supply. That is a legal question which does not require me to canvass or express a view on the arguments for and against fluoridation.

The failed arguments put forward by New Health NZ did not relate to the science but to legal issues. Specifically they argued councils do not have the legal right to make decisions on fluoridation, or if they do this is a breach of the NZ Bill of Rights Act (NZBORA).

Justice Hansen’s judgment that councils do in fact have the right to make decisions on fluoridation is quite detailed – and well beyond my legal ability so I will not comment on it.

Medicine and the right to refuse

Justice Hansen’s  judgments on the NZBORA are clear to the layperson. Inclusion of medical treatment in the NZBORA “was a specific response to the atrocities of the Nazi concentration camps.” However:

[80] In my view, fluoridation cannot be relevantly distinguished from the addition of chlorine or any other substance for the purpose of disinfecting drinking water, a process which itself may lead to the addition of contaminants as the water standards themselves assume. Both processes involve adding a chemical compound to the water. Both are undertaken for the prevention of disease. It is not material that one works by adding something to the water while the other achieves its purpose by taking unwanted organisms out.

[81] The addition of iodine to salt, folic acid to bread and the pasteurisation of milk are, in my view, equivalent interventions made to achieve public health benefits by means which could not be achieved nearly as effectively by medicating the populace individually. . . . All are intended to improve the health of the populace. But they do not, in my view, constitute medical treatment for the purpose of s 11″ [the relevant section of the NZBORA].

Even if the “medication argument” was relevant the “right to refuse” is irrelevant for fluoridation:

“Provided it does not have consequences for public health a person has the right to make even the poorest decisions in respect of their own health. But where the state, either directly or through local government, employs public health interventions, the right is not engaged. Were it otherwise, the individual’s right to refuse would become the individual’s right to decide outcomes for others. It would give any person a right of veto over public health measures which it is not only the right but often the responsibility of local authorities to deliver.”

Appeal – the fly in the ointment?

In principle this should remove any legal or judicial questions that may have concerned councils. They should now be able to go ahead with fluoridation. The Hamilton City Council,  got itself into a mess last year by deciding to stop fluoridation and was then forced into allowing a referendum which showed almost 70% support for fluoridation. The Council delayed putting the referendum result into effect citing the High Court case. They should now have no excuse to ignore the referendum result.

Unfortunately, New Health NZ will appeal the judgment – and this give wriggle-room to anti-fluoridation councillors, and councillors worried they may still yet face costly legal action, to argue that fluoridation remain suspended.

And that is most probably their intention with the appeal. New Health NZ must realise that the thorough judgment really gives them no room to pursue their arguments. But tactically this appeal could continue the hiatus situation faced by Hamilton and other councils. A decision on the appeal could be delayed for another year or so – meanwhile a number of New Zealand cities could be denied the advantages of a well proven and safe social health measure.

That likely motive is politically cynical and I hope the appeal decision will award costs against New Health NZ for that reason. Mind you, a simple analysis of the links of New Health to the corporate interests of the “natural” health industry shows cost is not a problem for them.

The deep pockets of the anti-fluoridationists

A while back I described the links between New Health NZ and the “natural” health industry – see  Who is funding anti-fluoridation High Court action? Specifically, New Health NZ is a creation of the New Zealand Health Trust – a political lobby group financed by the “natural” health industry.

This trust is also registered as a charity – which means we are all subsidising their campaigns via their tax exempt status. (Their charitable status really needs challenging).

However, the financial returns available on the NZ Charities Register shows large grants to the trust which in effect pay for their legal expenses (see figure below for year ended 31 March 2013).

One report estimated the cost to the South Taranaki District Council of this High Court action was about $200,000. Relatively small change for the corporate funders of the NZ health Trust/New Health NZ – but certainly large enough to scare individual councillors.

The government should recognise that such a David vs Goliath situation gives an unfair advantage to these corporate interests. This, together with a highly motivated and organised group of anti-fluoride activists enables individual councils to be picked off one by one by a combination of political and financial pressure.

Most councils would prefer the responsibility of decisions on fluoridation be handed over to central government. The find the continual re-litigation of the issue by anti-fluoride activists frustrating, time-consuming and expensive. So far the current government has resisted these call. Perhaps, though, a useful interim step would be for central government to indemnify local bodies on the fluoridation issue.

This would remove the financial pressure of the sort used by the NZ Health Trust/New Health NZ on cash-strapped local councils.  The anti-fluoride movement would then be forced to deal with central bodies which have more substantial financial backing and better legal and scientific resources.

Judgement summary and conclusions

[116] New Health has challenged the Council’s decision to fluoridate the drinking water of Patea and Waverley on the grounds that:

(a) There was no legal power to do so.
(b) If there was power, its exercise by the Council was a breach of the right to refuse medical treatment in s 11 of NZBORA.
(c) In making the decision, the Council failed to take into account relevant considerations.

[117] I have rejected all grounds of challenge. I have concluded that there is implied power to fluoridate in the LGA [Local Government Act] 2002, as there had been in the antecedent legislation, the Municipal Corporations Act 1954 and the LGA 1974. The Health Act confirms that fluoride may be added to drinking water in accordance with drinking water standards issued under that Act. The power to fluoridate drinking water is not a regulatory function; it does not require express authority. Nor does a decision to fluoridate require the consent of the Minister of Health under the Medicines Act as water is not a food for the purpose of that Act.

[118] I have concluded that the fluoridation of water is not medical treatment for the purpose of s 11 of NZBORA [NZ Bill of Rights Act]. While I accept that fluoridation has a therapeutic purpose, I conclude that the means by which the purpose is effected does not constitute medical treatment. I am of the view that medical treatment is confined to direct interference with the body or state of mind of an individual and does not extend to public health interventions delivered to the inhabitants of a particular locality or the population at large. I see no material distinction between fluoridation and other established public health measures such as chlorination of water or the addition of iodine to salt.

[119] In the event that, contrary to my view, fluoridation does engage the right to refuse medical treatment, I discuss whether in terms of s 5 of NZBORA the power to fluoridate is a justified curtailment of the right to refuse medical treatment. I conclude that it is. The evidence relied on by the Council shows that the advantages of fluoridation significantly outweigh the mild fluorosis which is an accepted outcome of fluoridation.

[120] Finally, I examine whether the Council failed to take into account relevant considerations in reaching its decision. I am of the view that the Council was not required to take into account the controversial factual issues relied on by New Health. There is, nevertheless, a plenitude of evidence to show that the Council carefully considered the detailed submissions presented and reached its decision after anxious consideration of the evidence and careful deliberation.


[121] New Health’s application to review the Council’s decision fails.

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February ’14 – NZ blogs sitemeter ranking


Yes, we are interested in including your new blog in these rankings. Credit: The Health Culture

There are now almost 300 blogs on the list, although I am weeding out those which are no longer active or have removed public access to sitemeters. (Let me know if I weed out yours by mistake, or get your stats wrong).

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters.

Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for February 2014. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers.

Meanwhile I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings

Subscribe to NZ blog rankings by Email

Find out how to get Subscription & email updates

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The fluoride debate – what do the experts say?

The impending High Court decision on the legality of fluoridation in Taranaki, and Paul Connett’s current speaking tour in New Zealand is bringing the fluoridation issue into the news again. New Zealand’s Science Media Centre (SMC) responded by conducting a Q&A with public health experts on fluoride. Here are the results.

Professor Barry Borman

Associate Director, Centre for Public Health Research, Massey University (with Ms Caroline Fyfe), responds:

Given the body of scientific evidence available, are you convinced that water fluoridation is an effective public health intervention?

“The overwhelming evidence from the peer-reviewed literature is that community water fluoridation is a highly effective and cost effective public health method for improving the oral health status of a population.”

What are the main benefits of fluoridation in New Zealand?

“Improving the oral health of the population, especially among those populations which have a poor oral health status, for example those on low incomes.”

What is at stake if more communities choose to end the practice?

“Depriving their local population of a cost effective method for improving (and/or maintaining) the oral health.”

Why do you think water fluoridation continues to be such a heatedly debated issue?

“Primarily because of the engrained views held by both the anti-fluoridation and pro-fluoridation groups, together with a lack of understanding and appropriate interpretation of the literature and nuances involved in the many studies. In many instances, results from the literature are used to support a view, but many of the studies have used poor study design, lack validity, and have varying degrees of bias. It is the validity of the study design that is critically important and not just the focus on the results.

“For example, a number of studies have been carried out in areas where the naturally occurring high levels of fluoride (eg, China and India) are well in excess of those used for community water fluoridation in New Zealand. Some studies adjust for the potential effects of all sources of fluoride, while others don’t, while some make an adjustment for differences between study and control population, while others don’t. The results from a recent meta-analysis showing a relationship between water fluoridation and children’s IQ have been widely used to support the position of the anti-fluoridation lobby, However, the study results have been shown to be flawed in a number of aspects (Borman B, Fyfe C. Fluoride and children’s IQ, NZ Med J, 2013).

“Much of the current confusion over community water fluoridation can also be attributed to the poor communication of the science by scientists.”

What should public health officials be doing to more effectively engage the public on this issue?

“Develop a greater understanding of the principles and techniques of risk communication and how a population perceives a risk to their health. The old adage remains: the things that scare people are not necessarily the things that kill or harm them.”

Professor Murray Thomson

Professor of Dental Epidemiology and Public Health, University of Otago, responds:

Given the body of scientific evidence available, are you convinced that water fluoridation is an effective public health intervention?

“Yes. It is important to remember that community water fluoridation is not a “magic bullet”, though; it will not eliminate tooth decay, but it will reduce it. How? Tooth decay begins as very small “etchings” of the dental enamel; these occur as dietary sugars are fermented (turned into weak acids) by bacteria within the plaque biofilm which forms on the tooth surface.

“Once those sugars have been used up, that demineralisation can be counterbalanced with subsequent remineralisation by calcium and phosphate ions from the saliva, slowly replacing the minerals which were lost. There is a continual cycling between demineralisation and remineralisation; the longer spent in the former, the greater the chance of a cavity. If fluoride is present, it not only enters the enamel, making it more resistant to acid attack, but it also inhibits demineralisation and the plaque bacteria.

“NZ evidence of fluoridation’s effectiveness has come from a number of studies which have shown that not only is decay experience lower among children living with community water fluoridation, but socio-economic inequalities are also lower. Data from our most recent national oral health survey provide evidence for a considerable effect in adults as well – and this effect is becoming more important as more and more Kiwis retain their teeth into old age. The benefits are there for Kiwis of all ages.”

What are the main benefits of fluoridation in New Zealand?

“Lower dental caries rates among children and adults alike. Fewer small children having to have teeth removed in hospital under a general anaesthetic. In area without community water fluoridation, children who do have to have that done present with more decay and at a younger age. Systematic reviews of the international evidence show that adults drinking fluoridated water have 27% less tooth decay experience. Given that the average middle-aged NZ adult has had 18 decayed, missing or filled teeth, that’s a difference of 4 teeth affected, on average.”

What is at stake if more communities choose to end the practice?

“There will be much more tooth decay, and that will have its greatest impact among people living in socio-economically deprived areas, as well as among Maori and Pacifika. It won’t happen overnight, of course, given the chronic, cumulative nature of the disease, but it will definitely get worse. Those who are opposed to community water fluoridation assert that we don’t need it: they argue that people can take fluoride tablets, brush with fluoride toothpaste and use mouthrinses if they want to use fluoride to prevent decay.”

“That’s all very well for the ‘worried well’ in the middle classes (who tend to have more positive self-care and health behaviours anyway), but it is neither feasible nor humane to leave the rest of the population to it. For example, we know from the 2009 national dental survey that only 59% of adults in the most deprived 20% of neighbourhoods brush their teeth twice daily with fluoride toothpaste. There is therefore a role for the State in preventing tooth decay in the NZ population: community water fluoridation remains the most efficient, effective and rational way to do it.”

Why do you think water fluoridation continues to be such a heatedly debated issue?

“There is a small but very vocal minority who have an anti-science, anti-public health agenda. They are very good at targeting the local body politicians who have to make the decision on whether to fluoridate or not. Being single-issue zealots, they have plenty of time and energy to do so. They are also funded well enough to bring overseas rhetoricians/polemicists into NZ periodically on speaking tours.”

What should public health officials be doing to more effectively engage the public on this issue?

“That’s a good question. The doggedness and sheer persistence of the anti-fluoride lobby means that public health officials could easily spend all of their time on the issue, but they actually have a plethora of more pressing, relevant public health issues to deal with, such as dental caries, tobacco, our alarming and rising obesity rates, and so on.” 

If you would like to contact a New Zealand expert about fluoride, please contact the SMC (04 499 5476;

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January ’14 – NZ blogs sitemeter ranking


Image credit:  Image from bLaugh 

UPDATE: Sorry, the data posted earlier today was old – now updated and hopefully correct. Apologies to early viewers.

Sorry this is a few days late – combination of Sitemeter playing silly buggers and me having family business taking me out of town.

There are now almost 300 blogs on the list, although I am weeding out those which are no longer active or have removed public access to sitemeters. (Let me know if I weed out yours by mistake, or get your stats wrong).

Every month I get queries from people wanting their own blog included. I encourage and am happy to respond to queries but have prepared a list of frequently asked questions (FAQs) people can check out. Have a look at NZ Blog Rankings FAQ. This is particularly helpful to those wondering how to set up sitemeters.

Please note, the system is automatic and relies on blogs having sitemeters which allow public access to the stats.

Here are the rankings of New Zealand blogs with publicly available statistics for January 2014. Ranking is by visit numbers. I have listed the blogs in the table below, together with monthly visits and page view numbers.

Meanwhile I am still keen to hear of any other blogs with publicly available sitemeter or visitor stats that I have missed. Contact me if you know of any or wish help adding publicly available stats to your bog.

You can see data for previous months at Blog Ranks

Subscribe to NZ Blog Rankings

Subscribe to NZ blog rankings by Email

Find out how to get Subscription & email updates

Image credit: Ryan Shell

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Fluoride debate: Final article – Ken Perrott

This is the last, final, article in the Fluoride debate. There will be nothing more. It is  Ken Perrott’s response to Paul Connett’s last article Fluoride debate: Paul Connett’s Closing statement.

For Paul Connett’s original article see – Fluoride debate Part 1: Connett.

“Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.”― Carl Sagan

Paul has used his right of reply and it really is time to close off this exchange.

I am not going to sieve through Paul’s long article and comment point by point – we are well past this. Instead I will discuss a basic issue central to the exchange (Paul’s reference to “weight of evidence analysis”) and show with several examples how superficial, and unscientific, Paul’s understanding of the approach is.

“Weight of evidence” – different things to different people

Weight of evidence can mean anything from a vague metaphorical description to a methodological approach or a theoretical/conceptual framework. Paul doesn’t clarify any further, but when he talks about balancing one set of studies or papers against another I find his concept very mechanical. It reminds me of the way the Hamilton City Council treated the submissions to last year’s hearings on the fluoridation issue (see my article When politicians and bureaucrats decide the science). Council staff reported:

“Of the 1,557 submissions received 1,385 (89%) seek Council to stop the practise of adding fluoride to the Hamilton water supply. 170 (10.9%) seek Council to continue the practise of adding fluoride and 2 (0.1%) submitters did not indicate a stance.”

Council, and Council staff, were impressed by these numbers – after all, place the submission printouts on a kitchen scales and of course the anti-brigade wins! Silly, I know, but this was one of the arguments staff supplied to council for ignoring the result of the referendum (where almost 70% supported fluoridation), at their November 2013 meeting. This extract from the draft resolution submitted by staff:

“All evidence has been considered carefully by Council and, while finely balanced, Council preference is to continue not to fluoridate the city water supply because: . . .

vi. Not fluoridating the city water supply reflects the majority of views expressed through the Council tribunal process.”

The silliness of such an approach is obvious when one starts to consider the quality and not the quantity of submissions. Here are a few examples from those opposing fluoridation:

Submission No 58:

I do not believe there is enough evidence to support the mass medication of our water supply’s for the good of all people. It is our right to choose to medicate ourselves with fluoride not the government right to force this medication I believe the fluoride in our water is toxic and needs to be stopped.

Submission 60:

Water Fluoridation is medication ‐ even if the pro fluoridationist say it is not. Council does not have the right to medicate the water. Please STOP!

Submission No 61:

From what I have come to understand, Fluoride is a toxin that has been and will continue contribute to chronic long term health illnesses. Fluoride a toxic substance we don’t want in our water supply for our younger generation to be exposed to.
Regards Connie

Submission No 65:

I do not want N0 KEMICALS into my drinking water.Thank you very much,Dorel”

Submission No 975:

“There is no acceptable reasoning to mass dose the whole population. There is a significant amount of information describing the side effects of Fluridation of the water supply. If people want extra Fluoride then they can take tables. 90% + of the fluoride added to the town supply ends up in the environment. There are more than 100 pesticides manufactured from Fluoride.”

Submission No 237:

I love New Zealand, it’s such a beautiful country. Fluoride is not necessary in the water supply. Please let people make their own choice about whether or not they want to ingest fluoride. It should not be forced upon anyone by adding it to the water supply. This is just plain and simply wrong!”

The local anti-fluoride activist organisation, the Fluoride Action MNetwork of NZ (FANNZ), promoted such meaningless submissions by proving a template form for their supporters. They were going for quantity and not quality – they are political activists, not scientists.

This shows why I reject the mechanical “weight of evidence” approach Paul often seems to be advocating. He certainly fights hard to avoid consideration of the quality of evidence he uses.

I can only agree with a “weight of evidence” approach if it is qualitative, not simply and mechanically quantitative. In fact, I would avoid the term and instead say our approach should be a balanced one, looking (as far as practicable) at all the evidence and considering it critically and intelligently.

Hence the quote from Carl Sagan at the head of this article.

I don’t think Paul does this. I show this in my comments and responses below.

From logical possibility to conspiracy

Paul’s book, The Case Against Fluoride, provides clear examples of a formula he uses to cast doubt on existing science, build up a library of claimed negative effects of fluoride in the human body and to suggest the scientific community conspires to suppress research findings and prevent important research from going ahead. It’s the sort of stuff ideologically driven opponents of fluoridation lap up enthusiastically. These tactics are not new – we have seen it all before with the creationists and the climate change deniers.

This formula has 3 steps:

1: Advance a claim with no real evidence. This can be done in several ways.

A): Establish a logical possibility. Paul uses a lot of “possibles,” “mays,” etc., in his book. No research evidence at all is required for this – just speculation and suggestion. For example:

“. . . if fluoridation were to increase the rates of hip fracture in the elderly, it would be serious and certainly grounds in itself to eliminate water fluoridation.” (p174).

“. .  a possible mechanism exists whereby fluoride could bring about an excessive production of TSH from the pituitary. This may help explain why . . .” (p163).

“These speculations need to be investigated.”     “Although more difficult to prove, it is reasonable to assume that many of the effects seen in vitro can occur in the whole body.” (p125)

“The bone is the principal site for fluoride accumulation within the body, and the rate of accumulation is increased during periods of rapid bone development as occurs in growth spurts during childhood. Thus, the cells in the bone are exposed to some of the highest fluoride concentrations in the body.” (p182)

This last speculation is fallacious as fluoride exists as a structural component of the solid bioapatites in the bone – not in solution – so the term “concentration” is misleading.

B): Use poor research evidence. He often uses the old trick of implying a cause from a correlation, or using research papers who have relied on this fallacy.

The graph below illustrates the fallacy. Most of us find the suggestion eating organic food is the cause of autism silly and we are not at all convinced – despite the excellent correlation. Maybe there are a few people who are so hostile to organic food that they take this suggestion seriously – we can see how their bias might lead them to claim this as evidence and even promote their story with such figures.

But replace the organic food sales with a vaccination statistic – we have a demographic who serious believe vaccinations are harmful and would easily lap up such a fallacious figure. (We are getting a bit close to the bone here – Paul’s Fluoride Action Network (FAN) is organisationally aligned with anti-vaccination (National Vaccine Information Center), anti-GM (Institute for Responsible Technology), and similar outfits through the Health Liberty Coalition.)

Now do the same with a fluoridation statistic and we are getting into very familiar territory. Think Declan Waugh and his graphs showing correlations between fluoridation and practically every illness known to humanity. In fact, Declan Waugh is doing this for autism on his Facebook page. Here is his graph.

Another approach is to just rely on poor quality research – selected to fit his desired conclusions. Consider Paul’s obsession with poor quality Chinese research papers showing a negative correlation of IQ and fluoride concentration in drinking water. These studies have problems with IQ measurement and confounding factors. How can one seriously claim causation when the studies don’t consider, for example, detailed analysis of education and family social conditions. Or other more important contaminants in the environment,

Paul sort of admits speculation or reliance on poor quality research but quickly leaves his admission behind in his eagerness to claim harmful effects:

“there are about twenty studies (albeit with questioned methodologies in some cases) suggesting potential damage to the brains of young children” (p156).”

“Although the validity of the scoring methods used for fractures is acknowledged by the authors to be questionable, this is a potentially important finding,” (p170)”

“At present there is no direct and unassailable proof that fluoridation per se harms anyone’s thyroid. This may be due to the paucity of studies conducted;” (p164)

“We emphasize that proof that fluoride acts on the thyroid in these ways in vivo is still lacking. Further research is needed, but, meanwhile, the mechanisms are plausible and based on existing science.” (p163).

“Although there is no direct evidence that fluoride can inactivate deiodinases, it is well known as an inhibitor of many enzymes, and the hormonal derangements reported in fluoride-exposed people have been interpreted in terms of effects on deiodinases.” (p162)

Paul builds his arguments on very flimsy foundations. He often admits as much but attempts to confound his readers with a fair bit of hand waving and Gish galloping.

2: Collect together any sources which can be interpreted to support the speculation. This may often need a bit of dredging – obscure journals or newsletters, comments recorded at meetings, foreign language sources, etc. Here a naive mechanical “weight of evidence” approach is useful as a pile of Byelorussian, Chinese, Indian, etc. papers from obscure or poor quality sources, often newsletters or reported statements and not scientific papers, weigh a hell of a lot more than one or two papers from reputable journals, by reputable research teams, who report contrary findings.

And of course the well-known problem of lack of reporting negative effects weighs in at zero.

Paul is very proud of the 80 pages of citations in his book. But many of them are repeated several time, are from sources not normally considered for scientific citation, or from sources difficult to track down. Very many of the citations are to his own activist FAN web site. A particularly disturbing aspect of the last sources (often used when referring to translation of foreign language material) is that very often the links lead nowhere. They have either been lost during web site reorganisation or may never have even existed. Who is to know?

3: Use the lack of reputable sources for his claims as evidence of a conspiracy. Paul can “double dip” with the “missing” research and publications from credible reasearch teams and journals. He records paucity of evidence from credible sources to support his own claims relying on poor quality sources, then implies the lack of material indicates at least an unwillingness to research problems or at worst a conspiracy not to do the research and/or hide the results. Of course such descriptors of unwillingness or conspiracy can also be turned on researchers or publications with contrary evidence. He can discount them by suggesting links with industry or personal bias – hence introducing a sort of negative quality to good research while refusing to allow judgement on the quality of the bad research.

For example:

“Most of the concerns about the immune system are largely speculative; once again the scarcity of literature on this reflects a lack of interest by governments that promote fluoridation. The same can be said about reproductive effects; despite an extensive literature indicating that, at high levels of exposure, effects of fluoride on the reproductive system have been observed in a wide range of animals and reptiles, very few human studies on the subject have been published or even undertaken.” (p197)

“The failure to explore the plausible connection between fluoridation and arthritis in any fluoridating country is difficult to understand. It is particularly surprising since the causes of most forms of arthritis (e.g., osteoarthritis) are unknown but are usually associated with the aging process. For those living in fluoridated communities the aging process will coincide with lifelong accumulation of fluoride in their bones and joints.” p170/171)

“We do not claim that these IQ studies add up to conclusive evidence that water fluoridation impairs cognitive development. . . . . it is wise to sit up and pay attention. The health authorities and governments of fluoridating countries show little sign of doing that.” (p156)

“A small minority of people, perhaps 1 percent, appear to be acutely sensitive to exposure to fluoride at the concentrations present in fluoridated water. The wide range of signs and symptoms resemble those seen in poisoning with larger amounts of fluoride. These findings date from the 1950s. However, far from leading to more extensive studies, they were ridiculed when introduced and have since been largely ignored.” (p136)

Fluoridation and IQ

Paul’s mechanical and selective understanding of “weight of evidence” sticks out like a sore thumb when he claims fluoride influences development of the child’s brain. Even though he notes the mainly Chinese studies he relies on had “questioned methodologies in some cases” (p156 of his book) this is perhaps his most favourite claim for rejecting fluoridation. In his last article he even spent some time developing a margin of error from the studies – rather previous, I think, as he had not established that the data he used was reliable or indicated causation

The European Scientific Committee on Health and Environmental Risks (2010) took a more intelligent and critical approach to the Chinese studies. This from their document Critical review of any new evidence on the hazard profile, health effects, and human exposure to fluoride and the fluoridating agents of drinking water:

“A series of studies on developmental effects of fluoride were carried out mostly in China. They consistently show an inverse relationship between fluoride concentration in drinking water and IQ in children. Most papers compared mean IQs of schoolchildren from communities exposed to different levels of fluoride, either from drinking water or from coal burning used as a domestic fuel. All these papers are of a rather simplistic methodological design, with no – or at best little – control for confounders, e.g., iodine or lead intake, nutritional status, housing condition, parent’s education level or income.”

This document concluded:

“Available human studies do not allow concluding firmly that fluoride intake hampers children’s neurodevelopment. A systematic evaluation of the human studies does not suggest a potential thyroid effect at realistic exposures to fluoride. The absence of thyroid effects in rodents after long-term fluoride administration and the much higher sensitivity of rodents to changes in thyroid related endocrinology as compared with humans do not support a role for fluoride induced thyroid perturbations in humans. Limited animal data cannot support the link between fluoride exposure and neurotoxicity,
noted in the epidemiological studies, at relevant non-toxic doses. SCHER agrees that there is not enough evidence to conclude that fluoride in drinking water may impair IQ.”

The NZ National Fluoridation Information Service (2013) also critically reviewed literature on this issue (see NFIS Advisory A review of recent literature on potential effects of CWF programmes on neurological development and IQ attainment).They concluded:

“The available evidence raises the possibility that high levels of fluoride in drinking water may have subtle effects on children’s IQ. However all of these studies have limitations in design and analysis, a clear dose-response relationship between DWFCs and assessed IQ are often not evident. The study authors are frequently very cautious in their comments, and several noted that any indicated negative effect applied only to high DWFCs. An hypothesis of fluoride neurotoxicity would also be supported by some experimental animal studies, however the great majority of these have only considered high fluoride intakes.

However collectively the data described are not robust enough to draw a firm conclusion that high fluoride levels in drinking water supplies contribute to retarded development of children’s brains. Also there is no clear evidence to suggest an adverse effect on IQ at lower fluoride intakes such as that likely to occur in New Zealand, where fluoridated water supplies contain fluoride in the 0.7 to 1.0 mg/L range.

Thus the balance of current scientific evidence does not suggest any risk for the development of full IQ potential for New Zealand Children from current community water fluoridation initiatives, where maximum DWFCs are 1 mg/L.”

Paul will respond that the studies were good enough to warrant further investigation but then he alleges that western researchers are either willfully ignoring these studies or even conspiring to suppress them and refuse to investigate further.

He never considers that, perhaps, the lack of better quality studies really is evidence of lack of effect – given the reluctance to publish studies with nil results.

Think about it, if there really was this effect from salt, milk or water fluoridation wouldn’t we be aware of it by now? After all, many countries do collect the sort of data about their populations, especially children, which would show any effect.

Maybe publication of the Choi et al (2012) meta-review will encourage more specialists to extract this data in their own countries and publish analyses. I personally know of one such study in New Zealand which shows no IQ effect of fluoridation. This study is of higher quality than the ones Paul relies on because  the data was sufficiently extensive to allow consideration of confounding effects (eg. breastfeeding, education, income level, etc.). A paper has recently been submitted for publication so unfortunately I cannot offer a citation until it is “in press.”


Again, the importance Paul gives to a single study on fluoride and osteosarcoma illustrates his mechanical and selective approach to “weight of evidence.” He has not bothered including either the study by Comber et al (2011) of this issue in Ireland or the study by Levy & Leclerc (2012) for the US. Possibly because both of these concluded that water fluoridation has no influence on osteosarcoma incidence rates.

The NZ National Fluoridation Information Service (2013) briefly considered this literature and cancer incidence rates for New Zealand (see Community Water Fluoridation and Osteosarcoma – Evidence from Cancer Registries). Their conclusion:

“The analysis confirms that osteosarcoma is extremely rare in New Zealand with only 127 new cases registered during this period averaging 14.1 per year. The peak age is 10 to 19 years for both sexes. These rates indicate that there is no difference in the rates of osteosarcoma cases between areas with CWF and areas without CWF for both sexes, findings which are consistent with the two international studies.”

But, I guess, not consistent with the one study Paul relies on! A study Paul described as “unrefuted.”  See what confirmation bias does to “weight of evidence?” Although his “unrefuted” strangely conflicts with his qualification about this research in his book:

“The evidence that fluoride causes osteosarcoma is not clear-cut. The studies of the relationships in both animals and humans are mixed.” (p 181)

Update: Here’s another paper published this moth which I guess Paul will studiously avoid. Blakey et al (2014). Is fluoride a risk factor for bone cancer? Small area analysis of osteosarcoma and Ewing sarcoma diagnosed among 0-49-year-olds in Great Britain, 1980-2005.

Breast feeding and the naturalistic fallacy

I understand Paul’s points about dose and dosage – they are not difficult concepts. Obviously they are important when we consider ingestion of fluoride and other environmental elements by infants. My reading indicates that those involved in health advice and regulation do consider dosage when discussing fluoride. I am at a loss to know why Paul thinks this issue is being avoided.

Paul keeps returning to the low level of fluoride in breast milk so I can’t help think he is still trapped by the naturalistic fallacy. He even links this to IQ claiming “whether by accident or by evolutionary “design” mother’s milk is protective against lowered IQ.”

Paul may make some mileage out of the naturalistic fallacy if he stays with fluoride, but bring in the other trace elements which present problems because of deficient levels in human breast milk and the fallacy has far less credibility.

A brief scan of the literature shows breast fed children are prone to some microelement deficiencies. For example, Kodama (2004) and Domellöf, et al (2004) report deficient levels of zinc, selenium and iron in breast milk. Supplementation of breast-fed infants with micronutrients, including fluoride, is sometimes recommended.

Hastings project

Paul’s treatment of this issue shows how simple his concept of “weight of evidence” is. He relies only on one-sided discussions by Colquhoun (1987), Colquhoun & Mann (1986), and Colquhoun & Wilson (1999). He seems not to have done anything to check the original papers from the project and relies on a single out-of-context letter from a bureaucrat which he interprets  to his own satisfaction.

  1. Paul adamantly and publicly declares the Hastings fluoridation project a “fraud.” That is an extremely serious charge in the scientific community – scientific   fraud is one of the worst accusations possible and usually leads to loss of career. It is unprofessional to make such a charge without being prepared to pursue it legally. I question the ethics of such an attack on people who are no longer here to speak in their own defense.
  2. Paul says:
    “What convinces me the final report was a fraud was the authors did not mention the change in diagnosis when claiming the drop in tooth decay was due to fluoridation.”
    Yet he does not reference the “final report” or show any indication he has checked this charge rather than take it on trust from his anti-fluoridation sources.
  3. He claimed in his second to last article that the decision to drop Napier as a control city was made for “bogus reasons” – yet gave absolutely no evidence to support such a serious claim. He now wants to  avoid that responsibility by saying the issue (his claim) is a “red herring.” Sorry Paul, one should not avoid responsibilities – if you wish to make a serious allegation be prepared to back it up or withdraw and apologise –  not run away from it.

I know from experience the complexity of long term trials involving many people doing different jobs. It is easy to take a bureaucratic letter out of context, oversimply or misinterpret problems of personal approaches to methodology and ignore the fact that managers of such trials inevitably face difficulties from factors outside their control. As for reporting findings, the data amassed and details of methodology and their changes can be mind-boggling for an outsider who attempts an understanding.

I will not pretend to have got my head around that project but here are a few observations:

  1. The findings from the trial were presented as scientific papers in the New Zealand Dental Journal (Ludwig and Ludwig, et al. 1958, 1959, 1962, 1963, 1965, 1971). The issues with Napier, originally proposed as a control, are discussed by Ludwig et al (1960), Ludwig & Healy (1962) and Healy et al (1962). Paul does not seem to have consulted any of these papers yet he considers his “weight of evidence” enough to make serious charges of “bogus” and “fraud!”
    The authors did not trumpet their study “showed that fluoridation was a great success” – scientists are usually more circumspect. In this case conclusions were more along the lines “The results obtained in Hastings during a period of  75-78 month’s fluoridation are very similar to results obtained overseas after a comparable period of fluoridation.” (Ludwig 1962).
  2. The important data was reported in papers from 1958 – 1971. These are very brief but all include the statement that further information on methodology, data and statistical analysis is available to interested people. The details Paul’s seems to want may be in that unpublished “further information.”
  3. Colquhoun & Mann (1986) and Colquhoun & Wilson (1987) both quote from unpublished reports and communications where discussion of diagnostics and methodological changes occurred. Colquhoun and Mann even report that researchers believed evidence from the Napier data indicates these changes did not have an overriding effect. Even a simple glance at the published data shows that the decline in tooth decay was not restricted to the early period where diagnostic and methodological changes would have been expected to exert any effect. Compare the plots below.


Hastings data shows similar improvement in oral health even if project had started in 1957. Plots are for different ages.

I think Paul is irresponsible to make such damning charges of “fraud” without considering all the material. He actually has no evidence at all the project was a “fraud” or that the reasons for dropping Napier as a control were “bogus.” His behaviour is unprofessional.

The problems with longitudinal studies

There are inevitable problems with longitudinal trials of the sort which the Hastings Project eventually became. They are influenced by undetected confounding factors and hence can be difficult to interpret. This may not have been sufficiently recognised at the time and that may have coloured interpretation of the results.

But let’s not forget that much of the harsh criticism of fluoridation made by Colquhoun (1997) and Diesendorf (1986) rely on their own biased interpretation of such longitudinal trails. And today’s anti-fluoridation propagandists make the same mistake even though we now know better. Paul himself used the WHO data showing improvement in oral health in many countries in his first few articles to argue that fluoridation had no effect. He did not consider the multifactorial causes of that improvement or mention that where measurements made in single countries (like Ireland) clear differences between fluoridated and unfluoridated areas were seen.

Should we now accuse Paul of “fraud” because he made no mention of the full Irish data in his claim that the WHO data showed fluoridation ineffective?

Paul continually avoids systemic role of fluoride

He does this by stressing the surface mechanism initiating caries is “topical” and not “surface” and works hard to imply “topical application” methods are required. He has conceded to including the word “predominantly” when referring to the surface mechanism but seems not to understand the meaning of the word.

My dictionary definition for “predominant” is “Most common or conspicuous; main or prevalent.” The word does not mean “only” as Paul seems to assume.

Neither is tooth decay simply about the initiation of caries. It also involves the strength and hardness of the teeth where systemic fluoride plays a beneficial role – especially during teeth development in the pre-eruptive stage. Paul continually avoids this as he also does the normal and natural role of fluoride in bioapatites.

Paul has not even acknowledged the citations I have given supporting this systemic function for fluoride. I guess all I can do is add another one – published this month - Cho, et al (2014). Systemic effect of water fluoridation on dental caries prevalence.

Paul’s concessions

I guess we should acknowledge there has been some progress during this exchange as Paul has made a few concessions. It is worth recording them here to show they have occurred – but of course I am interested to see if he still repeats his original claims elsewhere.

Fluoridated and unfluoridated data for the Irish Republic. Finally Paul seems to understand my point on this. At least he apologises and said he should have checked.

I really can’t understand why he was confused  for so long (I raised is in my first article) but we all have our moments, I guess. He should now understand that use of WHO and similar data showing improvement of oral health in both fluoridated and unfluoridated areas is not a proof that fluoridation is ineffective. This fallacy is repeated again and again by opponents of fluoridation and ignores completely the multiple issues involve in oral health. Scientifically literate people should not resort to such fallacies.

I will be interested to see if he avoids this fallacy in future. A sign of good faith would be for him to remove or amend the section on the FAN website which promotes this fallacy.

Xiang et al’s margin of safety calculation. I asked Paul several times to clarify this because he was using a figure of 1.9 ppm yet Xiang’s paper was completely silent on how the value was obtained and seems to ignore the large variability of the data –  another sign of poor reviewing by the journal Fluoride. Paul now seems to have walked away from reliance on Xiang et al (2003) and a threshold value of 1.9 ppm and wants to take a different approach.

But, he still wants to use the poor quality Chinese data and does nothing to justify using that data in the absence of demonstration of any causal, and not incidental, relationship between fluoride in drinking water and IQ. I think this makes his calculations meaningless.

In the meantime could he please remove the sections of his FAN website arguing for the 1.9 ppm margin of safety?

What happens when fluoridation is stopped. Paul has accepted my point that at least in the cases of the former DDR and La Salud, Cuba, the results are consistent with use of alternative fluoride sources such as fluoridated salt, mouth rinses and dental applications. While admitting I had a valid point he says:

“Ken responded that in two of these studies other measures were taken which might have explained why tooth decay did not increase. I in turn argued that that if this was the case it shows that there are alternatives to fluoridation that work.”

Two points.

No one claims there are no alternatives to fluoridated drinking water. I have pointed out again and again that there are. So why the red herring? Paul was citing these studies to “prove” fluoridation is ineffective and I showed his conclusions were not justified.

Paul appears desperate to cling to any case I have not looked at. Must I go through every example and look at the details? Can he not do this himself? If there are no mitigating circumstances this would surely support the argument he wants to make. We should not do science this way. We should always approach the literature and research critically and intelligently.

Having conceded on La Salud and the former DDR is he prepared to modify his claims about these situations in his FAN website?

National Fluoridation Information Service

Some discussion of this body is important as Paul’s confusion extends a lot further than its name. He is demonstrating how he cynically uses terms like “weight of evidence analysis.” Cynical because he rejects the very body (NFIS) that is taking this scientific approach in New Zealand and throws his advocacy behind the body which is biased, uncritical and unintelligent in considering the evidence. The body which cherry-picks literature and interprets it selectivity to support its confirmation bias. He supports the NZ Fluoridation information Service (NZFIS).

As I wrote in my last article the NZFIS is an astroturf organisations set up by the FANNZ. Paul well knows that FANNZ has a clear bias and political aims with a declared purpose of “bringing about the permanent end to public water fluoridation (“fluoridation”) in New Zealand,” (quote from FANNZ rules).

Simple consideration of the NZFIS web site shows that it does no active work on the fluoridation issue. It’s material is old, biased and there is no current activity. However, the organisation is used for distributing biased press releases and attempting to claim scientific credibility. (See, for example, my recent article False balance and straw clutching on fluoridation.)

I can understand why Paul throws his support behind FANNZ and the NZFIS. They are part of the international tentacles of his organisation FAN. This is not about science or “weight of evidence analysis” at all. It’s about political activism.

So of course Paul must bad-mouth the organisation which is doing the work and taking a scientific approach in NZ – the National Fluoridation Information Service (NFIS). He says:

“My concern here is the use of taxpayer money (about 1 million dollars) to support the promotion of fluoridation rather than presenting a balanced view of the evidence.”

Well he would say that wouldn’t he? He treats public funding of NZFIS as a smear! That is the typical naive conspiracy theory approach taken by climate change deniers and any other anti-science organisation who attempt to discredit scientific findings. It distorts the facts completely – governments don’t employ scientists to produce a predetermined conclusion – if they wanted that theologians would be more appropriate and a lot cheaper. Research funding is not used to confirm a bias but to employ the people and resources who can answer important questions.

He also seems to think dropping a figure like “about 1 million dollars” acts as a smear. Let’s put this into context – here is the NFIS budget for 2012/2013. From the 2012-2013 annual plan.


And, no, the NFIS does not spend its time issuing misleading press releases or providing institutional status to political activists. Here is how an early evaluation document described its role:

“NFIS is an information and advisory service which will support District Health Boards and Territorial Local Authorities by providing robust and independent scientific and technical information, advice and critical commentary around water fluoridation.”

Go to the NFIS website and have a look at its output – it is professional and balanced. It is a laugh to even compare the barely operating astroturf NZFIS with it. Of course Paul wants to discredit the NFIS – he would like our scientists and health professional to rely on his own biased political organisations instead.

My criticism of FAN

Paul says that in making criticisms of FAN I am playing a “pro-fluoridation activist rather than a scientist.” I disagree because scientists must be concerned about the quality of material they consider. The must be aware of ideologically driven cherry-picking, opportunist use of selected research and the promulgation of unwarranted conclusions being promoted for political or ideological reasons. This is all part of looking at all the evidence critically and intelligently.

Scientists are concerned about poor quality and misinterpretation. It is disingenuous of Paul to make an accusation of activism to ignore or deny, the legitimacy of these concerns.

Paul claims that even if “FAN is a terrible organisation .  . . That does not affect the scientific case for and against fluoridation.” I agree – the scientific case rests on objective reality and the science itself – not on reputation or rumour. But the determination and presentation of a case is very much influenced by the bias and the ideological and political positions of an organisation making the case.

In my last article I analysed the way that FAN worked to demonstrate why their information and claims are unreliable. I believe that was perfectly justified from a scientific perspective.

Similarly I think my arguments above analysing Paul’s mechanical interpretation of “weight of evidence,” and what he means by it in practice, are also justified from a scientific perspective.

Surely such analyses must be part of the critical  and intelligent consideration of the arguments of organisations and people? Isn’t this what Carl Sagan meant with:

“Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.”

Concluding message

Several times I have stressed my motivations in this debate are scientific and not supporting a specific policy. I am concerned at the way the scientific literature and findings are being misrepresented by ideologically driven activists. We have seen this before on issues like evolutionary science and climate change. Similar misrepresentation is currently rife among advocates of alternative and natural medicine and health. I believe it must be opposed.

Hopefully many readers have taken my point on this. While I currently believe fluoridation of drinking water is a worthwhile social policy in New Zealand I don’t see it as the end of the world if it is rejected by a community. Nor do I see it as the only way of overcoming deficient levels of fluoride in our diet. And, of course, there is always the possibility that future research may change the current scientific consensus that fluoride at the levels used in water or salt fluoridation is safe and beneficial. Science is like that. Because our knowledge is always provisional, but improving over time, we sometimes do modify our conclusions.

So, if readers take my point about the need to overcome misrepresentation of science in these sorts of issues I will consider participation in this exchange worthwhile – even if most readers do not change their political views on support or opposition to fluoridation of water.


Balls, M., Amcoff, P., Bremer, S., Casati, S., Coecke, S., Clothier, R., … Zuang, V. (2006). The principles of weight of evidence validation of test methods and testing strategies. The report and recommendations of ECVAM workshop 58. Alternatives to laboratory animals : ATLA, 34(6), 603–20.

Blakey, K. et al (2014). Is fluoride a risk factor for bone cancer? Small area analysis of osteosarcoma and Ewing sarcoma diagnosed among 0-49-year-olds in Great Britain, 1980-2005. International Journal of Epidemiology, 2014, January 14.

Cho, H.-J., Jin, B.-H., Park, D.-Y., Jung, S.-H., Lee, H.-S., Paik, D.-I., & Bae, K.-H. (2014). Systemic effect of water fluoridation on dental caries prevalence. Community dentistry and oral epidemiology.

Choi, A. L., Sun, G., Zhang, Y., & Grandjean, P. (2012). Developmental fluoride neurotoxicity: A systematic review and meta-analysis. Environmental Health Perspectives, 120(10), 1362–1368.

Colquhoun, J. (1987). Education and fluoridation in New Zealand: an historical study. Ph.D. thesis. University of Auckland, New Zealand.

Colquhoun, J. (1997). Why I changed my mind about fluoridation. Perspectives in Biology & Medicine, 41(1):29-44.

Colquhoun, J.; Mann, R. (1986). The Hastings fluoridation experiment: Science or swindle? Resurgence & Ecologist, 16(6), 243–248.

Colquhoun, J., & Wilson, B. (1999). The lost control and other mysteries: Further revelations on New Zealand’s fluoridation trial. Accountability in Research, 6(4), 373–394.

Comber, H., Deady, S., Montgomery, E., & Gavin, A. (2011). Drinking water fluoridation and osteosarcoma incidence on the island of Ireland. Cancer causes & control : CCC, 22(6), 919–24.

Diesendorf M. (1986) The mystery of declining tooth decay. Nature 322 125-129.

Domellöf, M., Lönnerdal, B., Dewey, K. G., Cohen, R. J., & Hernell, O. (2004). Iron, zinc, and copper concentrations in breast milk are independent of maternal mineral status. The American journal of clinical nutrition, 79(1), 111–5.

Healy, W.B.; Ludwig, T.G.; Losee, F. L. (1961). Soils and dental caries in Hawke’s Bay, New Zealand. Soil Science, 92(6), 359–366.

Kodama, H. (2004). Trace Element Deficiency in Infants and Children — Clinical practice. Journal of the Japan Medical Association, 47(8), 376–381.

Levy, M., & Leclerc, B.-S. (2012). Fluoride in drinking water and osteosarcoma incidence rates in the continental United States among children and adolescents. Cancer Epidemiology, 36(2), e83–e88.

Ludwig, T. G. (1958). The Hastings Fluoridation project I. Dental effects between 1954 and 1957. New Zealand Dental Journal, 54, 165–172.

Ludwig, T. G. (1959). The Hastings fluoridation project: II. Dental effects between 1954 and 1959. New Zealand Dental Journal, 55, 176–179.

Ludwig, T. G. (1962). The Hastings fluoridation project III-Dental effects between 1954 and 1961. New Zealand Dental Journal, 58, 22–24.

Ludwig, T. . (1963). Recent marine soils and resistance to dental caries . Australian Dental Journal, 109–113.

Ludwig, T. G. (1965). The Hastings fluoridation project V- Dental effects between 1954 and 1964. New Zealand Dental Journal, 61, 175–179.

Ludwig, T. G. (1971). Hastings fluoridation project VI-Dental effects between 1954 and 1970. New Zealand Dental Journal, 67, 155–160.

Ludwig, T. G.; Healy, W. B.; Losee, F. L. (1960). An association between dental caries and certain soil conditions in New Zealand. Nature, 4726, 695–696.

Ludwig, T.G.; Healy, W. B. (1962). The production and composition of vegetables in home gardens at Napier and Hastings. New Zealand Dental Journal, 58, 229–233.

Ludwig, T.G.; Pearce, E. I. F. (1963). The Hastings fluoridation project IV – Dental effects between 1954 and 1963. New Zealand Dental Journal, 59, 298–301.

NFIS (2013) Community Water Fluoridation and Osteosarcoma – Evidence from Cancer Registries. (2013), (May).

NFIS (2013) A review of recent literature on potential effects of CWF programmes on neurological development and IQ attainment.

Scientific Committee on Health and Environmental Risks SCHER (2010).  Critical review of any new evidence on the hazard profile , health effects , and human exposure to fluoride and the fluoridating agents of drinking water.

Xiang, Q; Liang, Y; Chen, L; Wang, C; Chen, B; Chen, X; Zhouc, M. (2003). Effect of fluoride in drinking water on children’s intelligence. Fluoride, 36(2), 84–94.

The links to all the articles in the exchange are listed by date on the Fluoride Debate page. I will shortly  put the articles together in a PDF document (and maybe an eBook format) so readers can download and consult at their leisure. Maybe we could even use Paul Connett’s speaking tour of New Zealand early in the year to encourage people to read the exchange.

Thanks to Paul Connett for agreeing to this exchange (it was actually his idea to try it as an on-line exercise) and to all the people who participated in the comments discussion.

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