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Fluoride debate: Ken Perrott’s closing response to Paul Connett? Ken Perrott Dec 30

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This is Ken Perrott’s response to Paul Connett’s last article Fluoride debate: Arguments Against Fluoridation Thread. Part 8. Paul.

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

This exchange is now winding down – despite the fact we have not dealt properly with all the items on Paul’s original list. The exchange has become repetitive and personal. I think readers are becoming bored with this and would have preferred us to work through each item in turn and move on. Paul’s declaration he “will end my participation in this exchange forthwith” – unless  I specifically respond to his vague 4 point challenge (with 3 qualifying points) – makes an early conclusion inevitable.

As this is my last article in the exchange I want to deal with the nature of Paul’s activist organisation – the Fluoride Action Network. This is scientifically relevant because it raises questions about how science should be done and communicated. I will precede that with another look at some of the scientific issues Paul disputes and briefly respond to a number of points he persistently raises.

But first I will respond to Paul’s use of certain “debate tactics” and his criticisms of the comment discussion that has accompanied these articles.

A scientific exchange or a “debate?”

Many readers are familiar with the debating tactics used by the Christian apologist William Lane Craig. He is always promoting himself by challenging others to “debate” him on his own choice of topic. Undoubtedly he is skilled in formal debate procedure and understandably he wants to choose his own “weapons.” But, formal combative debates are more a sport than a way of resolving issues (that is why we never use formal debates in science), more about egos than reality. The objectionable part of Craig’s approach is his use of the debate format as his way of attempting to control discussion. He tries to determine what subjects are covered and demand discussion centre around his own arguments. Intrinsic to his approach is to continuously pass judgment on his discussion partners – declaring they have not dealt with his argument, have failed to counter them, etc. Acting as the de facto debate judge he attempts to center discussion around his own arguments and will inevitably declare his opponents have lost the debate. This judgement is of course faithfully reported by his followers – to hell with the content of the discussion.

Do readers recognise the similarity to Paul’s approach, or should I spell it out? No, I think it is clear.

Right from the beginning I insisted this exchange not be a debate in the gladiatorial sense (even though we have tended to use the term loosely in titles, etc). I rejected Paul’s request the discussion be restricted to his own book insisting we each have our own data and arguments and we should be free to choose and advance our own points. I know Paul did not want this but what could he do?

I think that is the normal mature way to approach scientific exchanges. It should not be about ego but for drawing out the existing evidence and enabling discussion partners to perhaps see things in a light they have not considered. It is not about winners and losers but about attempting to get a clearer picture of reality.

Moderating comments

Paul criticised my moderation of the discussion accompanying this exchange. He is upset that I did not prevent what he sees as personal attacks on him in comments being “part of the visible record on is matter.”

I recognised in undertaking to moderate discussion (a new thing for my blog but something I had been considering) that criticism was inevitable and my moderation would be used as an “excuse” when commenters were not effective. It has certainly been used as an excuse by a number of local anti-fluoridation activists for not participating in the discussion (but this has not stopped a lot of bad mouthing in the background on other forums like Facebook).

My approach to moderation was to hold back comments that were:

  • Clearly spam (such as posting videos without accompanying comment),
  • Extensive copy and paste without personal input (I personally feel insulted when commenters will copy and paste several pages from a book or web site, without any formatting to remove page numbers or add links),
  • Simply abusive without contributing to the discussion or providing information (No, I did not stop comments which were abusive or angry when they did have something of value in their arguments or information).

By repeating Steve Slott’s comment in the body of his article Paul has ensured his readers and supporters will now have Steve’s succinct criticisms and characterisations of Paul in front of them. Paul has extracted a single comment from almost 2000 and ensured it will be part of the public record by placing it in the body of his article. Presumably Steve will by chuffed that his comment was not lost to such readers by being buried in the comments section. Perhaps Paul would have been wiser to leave things as they were.

But perhaps Paul is suing this comment as a diversion – or an excuse to accuse me of some sort of unethical behaviour. Or maybe this just results from his regular email contact with New Zealand anti-fluoride activists who are currently doing the same and discussing their “distaste” for me with them.

Correcting some misrepresentations

Sorry about the brevity and large number of these responses – a bit of responsive “Gish galloping” on my part!

Paul claims I argue “that water fluoridation is the only way to go as far as fighting tooth decay is concerned” yet I have never argued that at all. Several times I have pointed out that other countries use different social policies like fluoridated salt, fluoridated milk, school mouth rinse programmes etc. I would be perfectly happy to see New Zealand switch to fluoridated salt, for example, if fluoridated water proved unacceptable to the majority of the population. In some ways fluoridated salt may work better than water because it would not be under the control of local councils vulnerable to being “picked off” by activist groups. And sometimes I question the technical possibility of reaching the more than 70% coverage through community water fluoridation required to reach the whole population.  Salt fluoridation was discussed quite a lot in the comments discussion.

He claims I have a “distaste for opponents of fluoridation in NZ.” He is wrong (I have friends and family members I love who disagree with me on this question). But yes I do have a distaste for the tactics used by some of the activists. I also object strongly to the arrogant misrepresentation of the science commonly advanced by these activists. I find the fact Paul is in email contact with local activists and discussing their “distaste” for me unpleasant. I can imagine how nasty that discussion gets, but does he think that sort of bad mouthing advances anyone’s case? And has he responded to their bitching by urging them to participate in discussions here (as I have), or did he warn them to keep away?

He accuses me of not acknowledging there could be a problem for some individuals with increased sensitivity to fluoride and that I attack studies and “numerous anecdotal reports that have waved “red flags” on this issue.” Did he miss my comments in my last article that “I am happy to concede there may be a small number of people like this – as for other common chemicals in the environment?” Perhaps he chooses to ignore my conclusion “Maybe the most empathetic solution is that society as a whole compensate this small number of people in some way to aid them with their predicament.”

Paul has several times argued for a “weight of evidence approach” to the literature on fluoride. I will discuss this in greater depth in the section on the Fluoride Action Network. In principle this is exactly the same as my insistence that we should be approaching the literature in an intelligent and critical way. We should be considering all the literature, assessing quality, understanding flaws and strengths, considering the possible role of confounding factors and drawing interim conclusions from this overview. I think examples in this exchange show Paul often does not do that. Instead he often relies on cherry picked papers of poor quality. He even argues the lack of higher quality papers is a point in favour of the poor quality ones, when it may simply indicate other researchers don’t see the effect he wants. And he often claims studies support his conclusions when they don’t.

Paul criticises public funding of an information service in New Zealand set up specifically to facilitate a “weighted evidence approach” towards fluoridation research. Perhaps this shows his hypocrisy in the use of the term. However, Paul is thoroughly confused on this so a little information is required (readers can also refer to my article Anti-fluoridationist astro-turfing and media manipulation).

The NZ Fluoridation Information Service (NZFIS) is not publicly funded as Paul claims. It is an astroturf organisation set up by FANNZ, part of Paul’s International Fluoride Action Network (see Anti-fluoridationist astro-turfing and media manipulation). The astroturfing is so clumsy they use the same contact address as FANNZ! Mary Byrne and Mark Atkin, activists for FANNZ, often act as spokespersons for NZFIS, using the organisation to give an air of credibility to their press releases. This astroturf organisation was also used to provide false credibility to Mark Atkin in an an exchange of opinion article written for the Journal of Primary Healthcare. It is sometimes used to disseminate propaganda for Paul’s FAN organisation using local press releases.

This aura of “credibility” rests on the confusion of the similarity of it’s name to the NZ National Fluoridation Information Service (NFIS). This is publicly funded and part of its role is to monitor the research literature and make summaries available. It is an information and advisory service supporting District Health Boards and Territorial Local Authorities by providing robust and independent scientific and technical information, advice and critical commentary around water fluoridation. It is the organisation that takes a “weighted evidence approach.”

Unfortunately the ploy of using similar names does confuse the news media at times. (The NFIS periodically has to set the media straight.) Apparently it even confuses Paul – and I have seen similar confusion from local anti-fluoridation activists.

Paul is still confused about the graphic I introduced early in this exchange showing data for fluoridated and unfluoridated areas of the Irish Republic. He insists it is a comparison of data for the Irish Republic and Northern Ireland. It is not. How many times must I repeat this?

He again avoids the importance of including social good in ethical considerations of social health policies like fluoridation. This time he does so by pretending that social benefits just don’t exist. And yet he seriously proposes alternatives such as the Scottish ChildSmile programme and the programmes used in other European countries. Fluoride treatments are an integral part of the Childsmile programmes and fluoridated salt and milk is part of the programmes used in many European countries. What this boils down to is his insistence on individual choice as his over-riding concern and his absolute rejection of any concept of balancing this against social benefits. His insistence that fluoride has no beneficial effects and concern for harmful effects is merely an excuse for his concentration on individual choice.

Paul’s emotional (or political) obsession with individual choice often comes though in the most unlikely places. Why should he use the term “forced fluoridation” in a polite scientific exchange? It is equivalent to a politician referring to public education as “forced secular education,” or our public health system as “forced free hospital care.” No one has secular education, free hospital care or fluoridation forced on them. There is always a choice for those prepared to make the effort to satisfy their convictions.

Paul claims I know “full well” he has disowned claims that “Hitler used fluoride to control prisoners.”  No, I didn’t (still haven’t reached  pages 256-258 of his book), but I am very pleased he has repeated his statements here. Let’s disseminate these points far and wide:

Paul Connett rejects the arguments of some of his fellow fluoridation opponents that fluoride has been used “as a method of mind control.” He also rejects speculations that fluoridation is a “sinister plot to ‘dumb down’ the population” or “part of some world wide plan to reduce the size of the global population.”

I hope his fellow anti-fluoridation activists in New Zealand read this and take it on board. I hope they publicise Paul’s comments. I hope spokespersons for the local organisations reprimand any of the supporters who make these claims (far more of them do than Paul seems to think).

And I hope that Paul himself will repeat these assurances during his upcoming speaking tour of New Zealand – and particularly take to task supporters (like local spokesperson Dr Anna Goodwin) who repeat such rubbish. From my perspective he needs to push that message home loudly and often.

So thanks for that Paul – but why did he ignore my similar request?:

“I have yet to see him condemn the atrocious propaganda, lies and personal attacks of propagandists like Alex Jones and Vinny Eastwood. It is not enough to say he doesn’t necessarily support all their positions. The fact that he uses their services, and they use his, makes such weak dissociation disingenuous.”

Is his refusal to condemn  such “atrocious propaganda, lies and personal attacks of propagandists like Alex Jones and Vinny Eastwood” an indication of his support for them?

He claims I wish to “avoid” education on oral health issues. That is just silly and he has no justification for the claim. Proponents of fluoridated water supplies, fluoridated milk, fluoridated salt, fluoride dental treatments, etc., just do not see the world is such a naive black and white way. Fluoridation in any form is not a substitute for good oral hygiene. Health authorities will often operate campaigns of all sorts aimed at fighting tooth decay and education about oral hygiene is very common. We do in New Zealand and Paul has several times referred to such programmes in Scotland.

Paul’s attempts to deny the scientific consensus about the contribution of fluoride in drinking water to increasing concentrations in saliva and tooth surface biofilms has become desperate and farcical. I can only conclude this is because he has been promoting the mantra of “topical application” as a way of hiding the “surface mechanism” message.

He insists I have ignored his claims on margin of safety asking where my comments on this are. Yet, several times he has ignored my request for him to justify the low safety of margin he derives from the paper of Xiang et al (2003). I find it hard to believe he has not seen my requests (although that would be possible if he has not been reading my articles seriously). However, this could just be a cynical ploy as part of his campaign to pretend I am avoiding issues. I mentioned this above in my comment on debating tactics.

Briefly on the pineal gland and calcification (although not as briefly as Paul’s Gish galloping reference to it). It is a favoured subject of many anti-fluoride propagandists and they often give it mystical overtones with reference to a third eye, etc. Calcification is not caused by fluoride – it is caused by calcium, phosphate and old age. Because the bioapatites in calcified tissues are actively undergoing mineralisation and remineralisation they easily incorporate fluoride into their structure and this leads to higher concentration of fluoride in calcified tissues than in bones generally.

A similar situation occurs with calcium rich plaque deposits in cardiac arteries. Li et al (2011) suggested that fluoride incorporated into such deposits could be used to identify their occurrence by measurement of  F-18 using positron emission tomography. They were describing a diagnostic method and yet Declan Waugh and other activists disingenuously use this paper as some sort of “proof” that fluoride increases the risk of heart attacks!

I am surprised Paul has taken the approach of blaming practically every illness or change on fluoride. Arthritis, early onset of menstruation, all the symptoms attributed to “fluoride sensitivity,” osteosarcoma and other cancers, hypothyroidism, and so on. It is a common tactics of the non-scientific, even anti-scientific, rank and file anti-fluoridation activists to blame all the ills of the world on fluoridation – but one expects more from a trained scientist.


Some of the ills fluoride gets blamed for.

Despite the many advantages of modern society we do appear to face an increase in some health problems. Obesity has become far more common, for example. Surely the scientific approach is to attempt to identify the real causes properly. To start by blaming fluoride (or any other chemical) without evidence, is misleading. It is even worse to insist on attributing this as a cause to the exclusion of all else and to demand research only into such a dogmatic hypothesis – as Paul does. This ideologically driven labelling is not only dishonest. It is dangerous as it diverts efforts away from proper objective research and serious investigation of the problems. It inhibits proper identification of causes.

Paul insists on using the authority fallacy – out of context quotations from authoritative figures. An example in his last article was that by David Locker. Perhaps he is not aware he is doing this – it seems to be an instinctive reaction for anti-fluoridation activists. He should appreciate that the world is never as simple as implied by such quotes. I see his resort to such fallacies as a weakness, not a strength.

The Hastings experiment

Paul’s description of the Hastings experiment is biased and reeks of conspiracy theory. He has since included the same information in an internationally distributed newsletter entitled “New Zealand Fluoridation Fraud.” This is being disseminated in New Zealand and, I suspect, Paul will push this story during his upcoming speaking tour here. I always consider allegations of scientific fraud  to be very serious. Usually a researcher’s whole career is at stake as it is one the most serious allegations that can be made.

Typically, Paul’s bias means he relies on a single source for his story. He writes that he “would be anxious to see if Ken can throw a different light on this matter.” While this is not the place to give a full and more balanced history of the Hastings experiment (and I haven’t done the research for this) I will make just a few comments to expose Paul’s bias.

Paul quotes John Colquhoun:

“The school dentists in the area of the experiment were instructed to change their method of diagnosing tooth decay, so that they recorded much less decay after fluoridation began.”

This just shows how simple facts can be distorted to fit a conspiracy theory. My own family remembers this change in dental technique by the school dental service because it was country-wide – not restricted to Hastings as Colquhoun, and Paul, imply. There goes the conspiracy theory and Paul’s claim of a scientific fraud.

Akers (2008) agrees these changes confounded the experiment:

“The changing of NZSDS [NZ School Dental Service] diagnostic criteria for caries and the cessation of the NZSDS nurses’ practice of prophylactic restoration of fissures further confused interpretations. While later antifluoridationists justifiably claimed that the changed diagnostic criteria contributed to the fall in caries (Colquhoun, 1999), their “science or swindle” questioning of methodology and findings (Colquhoun and Mann, 1986; Colquhoun, 1998; Colquhoun and Wilson, 1999) simplified confounding variables and dismissed international evidence supporting community water fluoridation as one factor in declining community caries incidence (de Liefde, 1998).”

So science, probably bad science, but not the “swindle” Paul wants to believe – and wants us to accept. As an aside, I think changes in dental practice like this will have also contributed to the graphs Paul and other anti-fluoride activists love to use to prove improvement of oral health in the absence of fluoridation – yet they never discuss that sort of detail. It is a potential problem with any longitudinal study and Colquhon was criticised for ignoring it in his own presentation of New Zealand data.

Akers also refers to the problem with using Napier as a control city:

“The abandonment of the control city (Napier) because it had a lower initial caries rate than that of Hastings (Ludwig, 1958) implicated soil science as a confounding factor in New Zealand cariology (Ludwig and Healey, 1962; Ludwig, 1963).”

I referred to my memories of this discussion about the role of other trace elements in dental health in a previous article (see Why I support fluoridation).

Yet, how does Paul express this: “after about two years the control city of Napier was dropped for bogus reasons.” So Paul considers the fact it was not suitable as a control to be bogus?

The Hastings experiment (or “project” or “demonstration”) was also confounded by political changes, birth of the anti-fluoridation activity in New Zealand, loss of support from the Hastings City Council, and so on.

That is the problem with conspiracy theories – they paint the world black and white which is very unrealistic. I expected far more professionalism from Paul than this.

The Scottish ChildSmile programme

Paul returns to this through quoting material from Bruce Spittle. What I find a little weird is that his original reference to this programme was as an argument for an alternative to fluoridation. But he seems oblivious that Bruce’s note reveals that use of fluoride varnishes is an integral part of the programme.

In fact the programme includes this target:

“At least 60% of 3 and 4 year old children in each SIMD quintile to receive at least two applications of fluoride varnish per year by March 2014.”

It is an excellent programme but only Paul seems to see it as an alternative to use of fluoride. Here is a quote from the ChildSmile programme:

“The Scottish Dental Clinical Effectiveness Programme (SDCEP) Prevention and Management of Dental Caries in Children guidance outlined that the benefits of fluoride varnishing should be extended to all children. They recommend fluoride varnishing twice a year to all children over two years of age.

Even at very low levels, fluoride in the plaque and saliva is able to alter the balance between demineralisation and remineralisation, favouring the remineralisation process. As the remineralisation happens in the presence of fluoride, the new mineral crystals are stronger and less susceptible to acid attack.

When fluoride is present in the saliva, the fluoride ions become concentrated in the plaque. When sugars then enter the plaque, the presence of fluoride reduces the conversion of dietary sugars into acid by plaque bacteria with less acid produced.

How fluoride varnish works:

  • it slows down the development of decay by stopping demineralisation
  • it makes the enamel more resistant to acid attack (from plaque bacteria), and speeds up remineralisation (remineralising the tooth with fluoride ions, making the tooth surface stronger and less soluble)
  • it can stop bacterial metabolism (at high concentrations) to produce less acid.

Fluoride varnish leads to heavy remineralisation of the enamel surface, and subsequent acid attacks will allow fluoride ions to penetrate more deeply into the tooth structure. Varnishes like Duraphat® are useful because they stay on the tooth surface for some hours, allowing slow release of the fluoride ion.”

Improving oral health and effects of stopping fluoridation

Despite our discussion of the errors in drawing the conclusions he does from declining tooth decay in European countries he continues to naively present that as “proof” fluoride plays no role in oral health. And he is still completely confused about the Irish data I presented – this was for one country, Ireland. I was not comparing Northern Ireland and Ireland in any way. His claims that oral health shows no decline when fluoridation is stopped involves a similar misrepresentation of the evidence.

I am glad he acknowledges the protective role of other fluoride treatments after fluoridation was stopped in La Salud, Cuba, and the former DDR. But seriously, did he not know that already? Had he not checked out the studies which activists rely in to make these claims? And will he now stop using those examples in future presentations and discussions? I suspect not.

This shows all the earmarks of cherry picking studies to confirm his bias and basing arguments on studies he has not bothered checking. He attempts to deflect criticism by saying “It is not clear if Ken believes that alternative methods were applied to explain the results in Finland and British Columbia.” Well, perhaps I should spell it out – I don’t have a “belief” about those studies because I have not checked them out. But I suspect they do not support Paul’s arguments against fluoridation any more than the Cuban and German studies do. (After all I am sure Paul would be describing the details by know if they did). He has already lost that argument and he is desperately clutching at his remaining straws while the rest of us have moved in to the next issue wishing to spend our valuable time on more important things.

Once again I can illustrate some of the problems with his cherry picking and simple interpretations by comparing the changes in oral health of two Scottish communities described in a study by Attwood and Blinkhorn (1991), “Dental health in schoolchildren 5 years after water fluoridation ceased in South-west Scotland.”

This compared caries prevalence in two towns in both 1980 and 1988. One town, Annan, had never had fluoridated water while the other, Stranraer, had it until 1983. The graphics show the results for 5 year old and 10 year old children.


Decayed missing and filled deciduous teeth for 5 year olds. Stranraer fluoridated until 1983. Annan not fluoridated.


Decayed missing and filled teeth for 10 year olds. Stranraer fluoridated until 1983. Annan not fluoridated.

Paul might want to seize on the Annan results to argue that fluoridation has no effect on oral health as they show the same pattern as the European data he loves to present. But in this case we see that stopping fluoridation did have a significant negative effect on caries prevalence for Stranraer – even though oral health of these children in the two towns was similar in 1988.

I fully accept this is just one study, and by itself is not conclusive (I don’t claim it is). Nor have confounding factors been considered. Paul can claim I have “cherry picked” it. All perfectly valid criticisms – but that only describes the process used by Paul and his fellow activists. They have chosen papers they think supports their case. That is not good science. We should be basing our conclusions on on a proper critical and intelligent review of all the studies – not selecting ones which suit us.

Even with the study of Attwood and Blinkton described above activists from either side of the fluoridation debate can select or cherry pick “evidence” to fit their predetermined case. To argue either that it “proves” fluoride is not effective for oral health as shown in Annan where tooth decay declined despite there being no fluoridation. Or to argue that it “proves” fluoride is effective because oral health declined after fluoridation in Stranraer was stopped.

Nature of Fluoride Action Network

Ii is important this exchange not finish without considering the nature and role of Paul’s activist organisation, the Fluoride Action Network (FAN). I commented in previous articles about the problems of scientists becoming involved in activism. FAN illustrates those problems of cherry picking, confirmation bias and group thinking. Here I will comment on some of the specific ways these are manifested in FAN and it’s international role in the anti-fluoridation movement.

Martin (1991) and Newbrun (1996, 1999) described the social base of anti-fluoride activism as a weird mixture of fundamental greenies, misguided environmentalists, food faddists, anti-science “naturalists,” chiropractors and right-wing extremists. I guess readers could add more to this list but anyone who has watched the videos of the submissions made by anti-fluoridation activists to the Hamilton City Council hearings this year will recognise all these elements. They are all ideologically driven, illustrate characteristics of cherry picking, confirmation bias and group thinking, and make extensive use of the services FAN provides.

These social groups, and their associated businesses, also provide an organisational and financial backing to FAN and it’s regional organisations like the Fluoride Action Network of NZ (FANNZ). One current example is the NZ Health Trust which attempted to get a judicial review of South Taranaki’s decisions on fluoridation in the High Court.

FAN works hard to select scientific literature which can be interpreted, or reinterpreted, to support the anti-fluoridation case. They have accumulated a large database of such literature – a useful resource for the naive internet commenter wishing to “prove” fluoridation is evil. This database, and its extensive internet use by activists, has produced high Google search rankings for articles promoting an anti-fluoride case – frustrating for the honest Google user attempting to find more objective material.

The organisation certainly searches far and wide for any scientific report or paper which can be used to further their cause. Apparently the normally accessible scientific literature has not been fruitful enough for this purpose so they are making more use of obscure foreign sources. They have put a lot of effort into translation of Chinese publications and recently put out a request for people to translate foreign material in other languages.

Clearly FAN is searching for anything that can be used as “evidence” for negative effects of fluoride in human and animal health. This is not a critical or intelligent approach to the literature. I am all for the possibility of finding interesting ideas in foreign untranslated and obscure papers – I have done so myself. But the FAN motives are all wrong. They are uncritical, unintelligent and selective in their search. The quality of the research they use is their last concern – which is hypocritical considering the frequent demands for proponents of fluoridation to produce replicated double-blind studies.

The FAN database gets a lot of unintelligent use by fluoride activists throughout the world. Naive quoting and citing is very common in social media like Twitter and Facebook. Commenters in blogs will often simply post a quote or even just a link – drive by trolls. People who commonly read and use the scientific literature properly shudder to see such unintelligent use as it downgrades the idea of scientific knowledge.

FAN also makes videos available for similar use.

In effect FAN heads an international network. There are “action networks” and “fluoride free” organisations in many countries and regions where fluoridation is an issue. In New Zealand there is FANNZ, as well as regional Fluoride Free structures and Facebook pages. Mary Byrne, National coordinator of FANNZ is also a Advisory Board member on Paul Connett’s FAN organisation.

These international links are apparent in the way that media is manipulated by planting propaganda material. FAN will issue press releases which get faithfully transmitted by the alternative media connected with conspiracy theorists, natural and alternative medicine and practitioners, food faddists, some environmental groups, etc. These press releases also get planted locally by groups like FANNZ, sometimes using its astroturf group, the NZFIS. They also get picked up and reproduced by bloggers. Links and simple, very often misleading, one liners get transmitted ad nauseam by Twitter and Facebook.

Sometimes the normal mass media will reprint a press release, or pick up an article from elsewhere giving it a prominence it doesn’t deserve. And of course, these are immediately promoted on Facebook and Twitter as if they were independently sourced stories.

Example of Israel and it’s decision to regulate on the mandatory stays of fluoridation.

Whether intentionally, or just because of human foibles, part of international promotion is the use of personality cult. We can see this in New Zealand with Paul’s upcoming speaking tour. Locally he is being promoted and advertised  as the “World Fluoridation Expert” – despite the fact that he has no research papers to his name on the issue. In a previous article I referred to his claimed 18 years research into fluoride and his self promotion as an expert:

“with such a reputation it is reasonable to expect a body of publications in reputable peer-reviewed scientific journals. My simple searching does not show any, although he does list 2 which I could not find on-line in a recent CV. Could Paul give us a relevant publication list? And links to the papers.”

Significantly, this is another of my questions Paul has chosen to ignore.

Local Facebook advertisement for Paul’s NZ tour.

Paul also has remained silent on my critique of the Fluoride journal and his relationship to it. His organisation FAN is currently campaigning to win respectability for that journal in the wider scientific community. I can understand FAN’s motives for this – but the tactics? Promotion of a journal by an activist organisation which often attacks science and scientists would normally be considered the kiss of death.

Concluding comments.

This is the last article in my exchange with Paul Connett. Although, if he insists, I will not deny him the right of reply.

I have enjoyed the exchange. It has been useful for me to get my ideas into some sort of order and to get a measure of the arguments used by opponents of fluoridation. In that respect I am conscious that Paul does not adhere to some of the common arguments used. I am glad he dissociates himself from some of the extreme right-wing propaganda in the anti-fluoridation movement claiming an Agenda 21 conspiracy to control population and keep us dumb. Nor does he promote the silly arguments claiming fluoridation was used for this purpose by Nazis in the concentration camps. The negative side is that we did not get to see those arguments presented properly and I did not get to look at them more critically.

There have been a large number of comments on these articles and I believe they are of higher quality than we commonly see in discussions of fluoride. Many commenters have presented useful arguments and information with many useful citations. I have found these valuable and urge readers to go back and browse comments for them.

The links to all the articles in the exchange are listed by date on the Fluoride Debate page. In the new Year I will 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.

Finally 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.

Putting vaccination risks into context Ken Perrott Dec 29

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Picked this graphic up on Facebook last night.

Some people seem hesitant to discuss vaccination in the comments so hopefully this gives them the excuse they need.

Really drives the message home, doesn’t it?

Fluoride debate: Arguments Against Fluoridation Thread. Part 8. Paul Ken Perrott Dec 25


This is Paul Connett’s response to Ken Perrott’s last article Fluoride debate: Response to Paul’s 5th article

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

Ken’s response to my last posting once again is incomplete and evasive. Let me review what has happened here.

Ken was asked to present the case FOR fluoridation. After four attempts Ken has produced very little science to support such a case.  In part 6 of this thread I laid out what I felt would be the necessary components for such a scientific case and asked some very specific questions in the hope that Ken would present that case.  Ken’s response has been disappointing

Ken’s response in part 7 of this thread

Apart from further discussion on the theoretical mechanism of fluoride’s topical mechanism of action, a few citations on benefits, more criticisms of the opponents of fluoridation and more discussion on the ethical arguments Ken failed to present many primary scientific studies to support the case for fluoridation. Instead, he either ignored the questions I posed, was evasive or sought to obfuscate the key issues I presented. This meandering response may satisfy Ken’s urge to demonstrate his general distaste for opponents of fluoridation in NZ (based on the emails I have received this distaste cuts both ways) but it does not advance his scientific case for fluoridation one iota.

Instead of making a serious or even good faith effort to address the scientific questions I posed he attempted to dismiss my whole effort by claiming that I was unfairly throwing the kitchen sink at him (my words). His own words were new to me. He described my series of specific questions as follows,

 “It’s a real Gish gallop – suddenly demanding answers about arthritis, kidney function, thyroid function, osteosarcoma, individual sensitivity to fluoride, menstruation, effect on babies, monitoring bone concentrations and finally, all or any health concerns in New Zealand. Without any background to any of the issues.  (Wikipedia describes Gish gallopers as using ‘a rapid-fire approach during a debate, presenting arguments and changing topics quickly’). “

As far as Ken’s claim that I have failed to present the background to my questions he is wrong on two counts. First, I have raised several of these issues before in one or both of our threads – thus there is nothing sudden about many of these questions. Second, plenty of background was laid down on all of the issues in our book The Case Against Fluoride, a pdf copy of which was sent to Ken over a month ago.

If Ken was more familiar with the literature he would have known that the response to each question I posed was not difficult at all.

One sentence on most of these questions would have sufficed, for the simple reason that incredibly NO (or very few) studies on these topics have been undertaken in NZ or other fluoridated countries like Australia, Canada, Ireland, Israel, the US or the UK. More specifically:

1) There have been NO attempts to investigate arthritis rates in fluoridated communities in NZ or other fluoridated countries, even though it is known that the first symptoms of fluoride poisoning of the bone are identical to arthritic symptoms. I have given citations to some of these studies.

2) There have been NO attempts to investigate a possible relationship between fluoridation and an earlier onset of menstruation in young girls or puberty in boys in fluoridated communities in NZ or other fluoridated countries, even though there is some evidence that this maybe occurring (Schlesinger et al., 1956) as well as Luke’s work on the pineal gland (Luke, 1997, 2001).

3) Neither NZ nor any other fluoridating country has attempted to investigate the issue that some individuals report increased sensitivity to fluoride even though independent observers (e.g. Taves, discussed in chapter 13 of our book) and one governmental organization (Australia’s NHMRC, 1991) have recommended that this sensible measure be undertaken. Ken does not acknowledge this and misses the point by attacking the studies and numerous anecdotal reports that have waved “red flags” on this issue.

4) There have been NO systematic or comprehensive efforts by government health agencies to monitor the fluoride levels in the urine, blood or bones of any fluoridated community in NZ or any other fluoridated country.  Australia’s NHMRC in 1991 recommended bone levels be collected as a basis for epidemiological studies on fluoride’s impact on the bone but no attempt has been made there in the 22 years that have elapsed since this recommendation was made; nor in NZ.

5) There has been NO published study refuting Bassin’s finding of an age-related window of vulnerability (ages 6 through 8) for young boys being exposed to fluoridated water and succumbing to osteosarcoma. The promised study (Kim et al, 2011) miserably failed to refute this finding despite the promises made in 2006 that it would do so.

6) There has been little or no attempt to see if the current epidemic of hypothyroidism in NZ and other fluoridated countries has anything to do with exposure to fluoride even though doctors in Argentina, France and Germany used fluoride treatment to lower thyroid activity in hyperthyroid patients from the 1930s to the 1950s (See Galleti and Joyet, 1958).

7) There have been practically NO studies investigating possible health concerns in NZ possibly associated with fluoridation. Nor have there been attempts to reproduce studies that have found harm in countries with high natural fluoride levels. I was not aware of any studies in NZ other than a small IQ study from the 1980s but I thought it wise to find out if Ken knew of any. But he didn’t respond. I also asked him if he felt the absence of study was the same as the absence of harm but again he didn’t respond.

8) There have been a number of studies on teeth in NZ and other fluoridated communities as if this was the only tissue of concern in the baby’s developing body or of concern for adults with lifelong exposure. Ken has still yet to discuss the wisdom – or otherwise – of exposing a bottle-fed baby to about 200 times the level of fluoride that nature intended (0.7 ppm in fluoridated water versus 0.004 ppm in mothers’ milk).

9) In short. While the NZ government has poured over $1 million into the NZ Fluoridation Information Service, which is little more than a PR operation for fluoridation, they have taken little or no steps to fund any primary studies to see if this practice is harming anyone in NZ.

More Broad-brush dismissals

On the issue of fluoridation’s effectiveness Ken attempts to use the same broad-brush dismissal of the citations I offered in support of my case that evidence for swallowing fluoride reduces tooth decay was very weak. Ken responded:

“So, I am not impressed by Connett’s paragraph of about 30 unexplained citations – nor by a long reference list at the end of his article.”

I am baffled as to why he should describe these citations as “unexplained” when I made it clear that the citations were all discussed in three chapters of our book (chapters 6-8).  Ken had already explained that he had read up to chapter 9 in our book so his claim that the citations are unexplained is rather sloppy. As far as the number of citations is concerned it would be more understandable if Ken was complaining about my giving too few citations, not too many!

I ask the reader to consider for a moment, which is more convincing – my extensive list of references to the literature which suggest the ineffectiveness of fluoridation or the very sparse list of references provided by Ken which he claims support the effectiveness of fluoridation. However, at least he gave some references here; he gave none on the health concerns I raised.

Instead of responding scientifically – or at least conceding that the science has not been undertaken – Ken chose to either ignore or obfuscate most of the scientific issues I raised in the following ways:

1) His response is very familiar. He chose to attack the messenger and ignore the message. From Ken’s perspective there is nothing wrong with the practice and promotion of fluoridation – it is Paul Connett and other opponents of fluoridation who are the problem!

2) Really substantial issues I have raised are being ignored, in some cases for the second and even third time of asking. For example where are his comments on the

a) difference between dose and concentration;

b) the need for a margin of safety analysis when extrapolating from the doses that cause harm in animal and human studies and

c) the need for a weight of evidence approach to the scientific literature on this subject.

 3) Where Ken does address an issue his response has often been evasive and clouded with obfuscation. For example see his response to my reasonable scientific request for a list of studies that negate or balance out (i.e. weight of evidence analysis) the long list of studies that indicate that fluoride can damage animal brain and interfere with human behavior and intellectual development. His response was to classify such a request as “the IQ gambit” and to bring up the distraction of “Hitler using fluoride to control prisoners” when he knows full well that I have disowned such claims in public and in writing. See for example, these quotes from our book:

“It is true that a few people who oppose fluoridation do so based on claims that Nazi Germany and other totalitarian regimes used it as a method of mind control. There is little evidence that would satisfy a historian to support such claims. The vast majority of fluoridation opponents repudiate such views and base their opposition on science and ethics.” (pp. 256-7)


“Two speculations we reject outright are that fluoridation is (1) some sinister plot to“dumb down” the population or (2) part of some worldwide plan to reduce the size of the global population.” (p.258)

4) Thus, Ken has still to present a substantial case FOR fluoridation based upon the citation of primary studies.

5) Unfortunately, he is leaving it to others to present some of his case in the comments section. I made it clear to Ken when we discussing the format of this debate that I was not interested in these kind of blog comments which become very personal and sometimes insulting. I thought we had agreed that this was going to be a scientific exchange between the two of us. I am not prepared to sift through the insulting chaff in the comments section to get to the scientific wheat.

Someone has forwarded to me a recent personal attack on me by Steve Slott, DDS:

Steve Slott | December 19, 2013 at 1:40 pm |

You got it Stuart. Sarah Palin epitomizes the antifluoridationist. Being totally oblivious to her own ignorance she just blusters along, totally bewildered as to why she gets no respect from the mainstream.

Forgive me for straying off topic, Ken, but the most frustrating thing about antifluoridationists is their ignorance, and their total oblivion to it. Somebody like Connett comes along with just enough education and charisma to come across as being an “authority” on the issue, yet totally lacking understanding of basic facts, far overestimating of his own knowledge, and convinces the blind followers who crave any and all anti-authoritarian causes, that the establishment is corrupt, ignorant, and lacks the “knowledge” that only he possesses through his “study” of new “emerging science “. Being totally unaware that what is “new science” to him is nothing more than basic knowledge of which the true experts and authorities have long since been aware and have fully addressed, he blusters forward confident that he has the “truth” on his side. The worldwide body of respected healthcare is either “corrupt “, conspiracy laden, or ignorant of the “facts” that he is trying his utmost to bring to their attention. Dentists are running the fluoridation show, yet are all dumber than doorknobs and totally lacking in any knowledge of the human body outside of the portions of the teeth that are visible above the gum line, and decision makers are all unwittingly manipulated by big money interests. The people to whom he plays buy into his spiel, lock, stock, and barrel, thus becoming in their own minds far more knowledgeable about the issue than the dumb dentists, corrupt mainstream healthcare, and unwitting politicians who are stripping away personal freedoms and poisoning everyone in the process. Portland and Wichita are poster-children for the chaotic circus side-show that he creates by convincing a very active, very vocal, very ignorant few, of the “validity” of his own ignorance.

Steven D. Slott, DDS

Ken you are the moderator of the comments posted on your website, can you explain to me how this comment contributes to the science of this debate? Can you explain to me why you allow this kind of personal attack on your opponent – completely unrelated to any scientific argument that I have raised – to be part of the visible record on this matter? Just what purpose does it serve other than to muddy the waters and poison the minds of any independent observers?  Surely such a posting has no place in a debate that is supposed to be about the science of this controversial issue.

Now I will address some of the issues on which Ken offered a response.

1) On Randomized control studies (RCT).

 I complained that after 68 years no government promoting fluoridation has undertaken an RCT to demonstrate effectiveness. This is the gold standard in epidemiology. In response , Ken suggests that I should have done an RCT of my own!

As far as safety is concerned I agree that you cannot prove a negative, however such an argument neither explains nor excuses the lack of responsible attention to health concerns by fluoridating countries.  The absence of study on many very important health concerns is inexcusable and cannot be explained away with rhetoric.

2. The ethical argument.

 Ken claims that opponents of fluoridation merely focus on the violation of informed consent and ignore the social benefits of the program. However, that line of argument assumes that:

 a) such a benefit actually exists (and Ken hasn’t presented much of a case for that yet);

b) that very little – if any -risk is involved (Ken hasn’t presented much primary evidence to support that);

c) that the benefits greatly exceed the risks (not possible unless Ken has produced a strong case for both a) and b) which he has not;

d) that there are no practical and cost effective alternative social strategies which avoid the violation of the individual’s right to informed consent. In this respect it is very disappointing that Ken has yet to comment on the successful program being used in Scotland to fight tooth decay in children from low-income families there. Nor has he reviewed any of the other programs being used in the vast majority of European countries that don’t force people to drink fluoridated tap water.

 I would also hope that at some point Ken would address the Precautionary Principle as it applies to the ethics of this issue (see chapter 21, in The Case Against Fluoride…)

3) Does tooth decay go up when fluoridation is halted?

 In two of the four studies I cited (from Cuba, former East Germany, Finland and British Columbia) where tooth decay did not go up when fluoridation was stopped, Ken says that other measures were taken in two of those communities (Cuba and former East Germany). That’s a good point. However, it undermines his argument that water fluoridation is the only way to go as far as fighting tooth decay is concerned. If these communities have found alternative methods why aren’t fluoridating governments studying these alternative methods? Again I refer to the successful and cost-effective program with children in low-income families in Scotland.

 It is not clear if Ken believes that alternative methods were applied to explain the results in Finland and British Columbia.

In personal correspondence I have had with Rudolf Ziegelbecker, Jr., from Austria, who has studied this matter (and his father before him) for many years, he maintains that there has been no increases in tooth decay in any of the European countries that have stopped fluoridation.  Is Ken aware of any evidence to the contrary?

 4. Does fluoridated water deliver a significant topical benefit over and above that delivered by fluoridated toothpaste?

 I notice that Ken twice combines discussion of fluoride’s topical exposure via water and via food. He states:

 “So fluoride concentrations in saliva after drinking water or eating food containing fluoride can be quite variable.”

“Fluoride concentrations in saliva and plaque do reach a maximum after drinking water and eating food containing fluoride…” 

This is interesting because it goes back to my original skepticism about drinking fluoridated water doing much of anything in the oral cavity before it goes down the gullet – that is unless one swishes. On the other hand I can understand that any fluoride present in food is going to be made readily available to both the tooth surfaces and the saliva during the chewing of food and therefore may participate in the theoretical mechanisms that Ken discusses.

If, in fact, this mode of delivery (i.e. via food) is the relevant one then Ken would do better either a) to recommend making fluoridated salt available to those who want it in NZ or b) recommend that parents tell their children to swish the fluoridated water in their mouths before they swallow it. But there we are back to education again, and that is something that Ken wishes to avoid. We are also back to the potential harm from swallowing fluoride.

Beyond theoretical mechanisms

Whatever the theoretical mechanism for fluoride’s action (and I will leave it to the specialists in this field to fight that out), as a promoter of fluoridation, Ken still has to demonstrate that the weight of evidence from epidemiological studies indicates that there is a significant benefit from drinking fluoridated water over and above the use of fluoridated toothpaste. I don’t think he has done that.

He has also yet to explain why it is in the largest surveys there appears to be little difference in tooth decay in the permanent teeth between fluoridated and non-fluoridated communities, states and countries (see chapter 6 in The Case Against Fluoride…), with the one possible exception of the comparison between the Republic of Ireland and Northern Ireland, that Ken has cited.

In short, in the majority of the large surveys the relationship between tooth decay and the presence or absence of fluoride in the drinking water does not appear to rise above background noise. However, the relationship between fluoride levels and dental fluorosis certainly does rise above background noise (see chapter 7 in The Case Against Fluoride…) as does the inverse relationship between tooth decay and income levels (see chapter 6 in The Case Against Fluoride…).

Nor has Ken addressed the fact that in the only study that has looked at tooth decay as a function of how much fluoride children were ingesting (from all sources) there was no significant relationship between the amount of fluoride ingested on a daily basis and the level of tooth decay (Warren et al, 2009).

Although the late Dr. David Locker was not opposed to water fluoridation, he did have the integrity to admit in the review of dental studies worldwide, which he performed for the Ontario government in 1999, that:

 “The magnitude of [fluoridation’s] effect is not large in absolute terms, is often not statistically significant, and may not be of clinical significance.”

My final challenge to Ken.

 Ken I have patiently tried to debate the scientific issues with you but apart from your interest in bioapatites and the theoretical mechanism of fluoride’s actions (both interesting subjects but insufficient to demonstrate the wisdom of forced fluoridation) I believe that you have offered little in the way of science to support the case for fluoridation. Meanwhile, as moderator you are allowing insulting and personal attacks on me by people like Steve Slott to be posted as part of this exchange. I am happy to engage in a rational scientific exchange on this issue but not happy for it to be an excuse for an unscientific attack on my integrity.

I would like to extend you one more shot at demonstrating that there is convincing primary scientific evidence, which shows:

 1) That the weight of evidence of the primary studies indicates that drinking fluoridated water provides a large and significant benefit to the permanent teeth.

 2) That the weight of evidence of the primary studies indicates that there is an adequate margin of safety to protect everyone drinking fluoridated water and getting fluoride from other sources from damage to the developing brain documented in areas of moderate to high natural levels of fluoride. Note: that margin of safety should protect for the bottle-fed infant.

 3) My preference would be for you to do the same with other health concerns that I have raised including those where we need to protect someone consuming uncontrolled quantities of fluoridated water over a whole lifetime – but if it simplifies matters for you, then for now I will settle for you just tackling the impacts on the brain (i.e. 2 above).

 4) That the benefits you demonstrate in 1) outweigh the risks I have presented in my book and in these threads.

And that the case you present in 1-4 is so strong that it justifies:

 a) overriding the individual’s right to informed consent to human treatment.

b) overriding the Precautionary Principle

c) ignoring the fact that there are alternative ways of fighting tooth decay which are universally available – and the successful programs that are reducing tooth decay in children from low-income families in countries like Scotland and most of the rest of Europe without forcing this practice on people who don’t want it.

As far as the Scottish program is concerned we can add a few more bones to the BBC report I included earlier. This is how my colleague Dr. Bruce Spittle summarized the situation in Scotland:

Instead of water fluoridation, the newly devolved Scottish Government opted, in its 2005 dental action plan (their Childsmile program), to pursue:

a) school-based toothbrushing schemes;

b) the offering of healthy snacks and drinks to children;

c) oral health advice to children and families on healthy weaning, diet, teething and toothbrushing;

d) annual dental check-ups and treatment if required, and

e) fluoride varnish applications  (The Scottish Government, 2005; Macpherson LMD et al., 2010; Turner S et al., 2010; Chestnutt, 2013; Healthier Scotland, Scottish Government, 2013).

Encouraging results have been reported from this national dental programme with the proportion of children in Primary 1 (aged 4–6 years) without obvious dental decay rising from 42.3% in 1996 to 67% in 2012 (Information Services Division  Scotland, 2012).

Similarly, the proportion of children in Primary 7 (aged 10–12 years) without obvious dental decay rose from 52.9% in 2005 to 69.4% in 2011 and 72.8% in 2013 (Information Services Division Scotland, 2013).

The introduction and uptake of nursery school toothbrushing is likely to have contributed to a large extent to the improved oral health in five-year-old Scottish children (Macpherson, 2013).

I know these are tough challenges but they are the kind of challenges that should have been tackled years ago by government agencies promoting the unusual (and I say unacceptable) practice of using the public water supply to deliver human treatment. But they weren’t. But for those who continue to support this practice like you the tasks above have to be addressed.

If you are not prepared to attempt this challenge in good faith then I will end my participation in this exchange forthwith.

Paul Connett,

Dec 22, 2013


Bassin EB  et al. (2006). “Age-specific Fluoride Exposure in Drinking Water and Osteosarcoma (United States),” Cancer Causes and Control 17, no. 4: 421–28.

Connett, P., Beck, J and Micklem HS. The Case Against Fluoride. Chelsea Green, White River Junction, Vermont, 2010.

Galletti P. and G. Joyet (1958). “Effect of Fluorine on Thyroidal Iodine Metabolism in Hyperthyroidism,” Journal of Clinical Endocrinology 18, no. 10: 1102–10.

 Healthier Scotland, Scottish Government, NHS Scotland (2013). Childsmile: home, parents and professionals. Available from:

Information Services Division Scotland, NHS National Services Scotland (2012). National Dental Inspection Programme 2012 Report. Available from: Care/Publications/2012-11-27/2012-11-27-DentalNDIP-Summary.pdf?27395266295

Information Services Division Scotland, NHS National Services Scotland (2013). National Dental Inspection Programme 2013 Report. Available from:

Jones CM, Woods K, Taylor GO (1997a). Social deprivation and tooth decay in Scottish schoolchildren. Health Bull (Edinb) 55:11-15.

Kim FM et al. (2011). “An assessment of bone fluoride and osteosarcoma.” J. Dent. Res 90(10): 1171-6.

Locker, D (1999). Benefits and Risks of Water Fluoridation: An Update of the 1996 Federal-Provincial Sub-committee Report, prepared under contract for Public Health Branch, Ontario Ministry of Health First Nations and Inuit Health Branch, Health Canada (Ottawa: Ontario Ministry of Health and Long Term Care, 1999.

Luke, J, 1997, “The Effect of Fluoride on the Physiology of the Pineal Gland,” PhD thesis, University of Surrey, Guildford, UK, 1997. Excerpts at and a complete copy of Dr. Luke’s dissertation can be downloaded at  (with the author’s permission).

Luke, J, 2001.  “Fluoride Deposition in the Aged Human Pineal Gland,” Caries Research 35, no. 2 (2001): 125–28.

Macpherson LMD, Ball GE, Brewster L, Duane B, Hodges C-L, Wright W et al. (2010). Childsmile: the national child oral health improvement programme in Scotland. Part 1: establishment and development. Br Dent J 209:73-78.

Macpherson LM, Anopa Y, Conway DI, McMahon AD (2013). National supervised toothbrushing program and dental decay in Scotland. J Dent Res 92:109-113.

McMahon AD, Blair Y, McCall DR and Macpherson LMD (2010). The dental health of three-year-old children in Greater Glasgow, Scotland. Br Dent J 209:E5. doi: 10.1038/sj.bdj.2010.723.

NHMRC (1991). National Health and Medical Research Council, The Effectiveness of Water Fluoridation (Canberra: Australian Government Publishing Service, 1991), 109.

NRC (2006). Fluoride in Drinking Water: A Scientific Review of EPA’s Standards (2006)

Schlesinger ER, et al. (1956) “Newburgh-Kingston Caries-Fluorine Study XIII. Pediatric Findings After Ten Years,” Journal of the American Dental Association 52, no. 3: 296–306.

Warren, JJ et al. (2009) “Considerations on Optimal Fluoride Intake Using Dental Fluorosis and Dental Caries Outcomes—A Longitudinal Study,” Journal of Public Health Dentistry 69, no. 2: 111–15.

Anyone wanting to follow the debate and/or check back over previous articles in the debate can find the list of articles at Fluoride Debate.

See also:

Similar articles on fluoridation
Making sense of fluoride Facebook page

Alan Turing receives royal pardon Ken Perrott Dec 24



Photo credit: The Telegraph

Here is the official press release on the Royal Pardon for Alan Turing.

Pardon for WW2 Code-breaker Turing

By Jamie Grierson, Press Association Home Affairs Correspondent

Second World War code-breaker Alan Turing has been given a posthumous royal pardon for a 61-year-old conviction for homosexual activity. Dr Turing, who was pivotal in breaking the Enigma code, arguably shortening the Second World War by at least two years, was chemically castrated following his conviction in 1952.

His conviction for “gross indecency” led to the removal of his security clearance and meant he was no longer able to work for Government Communications Headquarters (GCHQ) where he had continued to work following service at Bletchley Park during the war.

Dr Turing, who died aged 41 in 1954 and is often described as the father of modern computing, has been granted a pardon under the Royal Prerogative of Mercy by the Queen following a request from Justice Secretary Chris Grayling. “Dr Alan Turing was an exceptional man with a brilliant mind,”

Mr Grayling said.

 ”His brilliance was put into practice at Bletchley Park during the Second World War where he was pivotal to breaking the Enigma code, helping to end the war and save thousands of lives.

“His later life was overshadowed by his conviction for homosexual activity, a sentence we would now consider unjust and discriminatory and which has now been repealed.

“Dr Turing deserves to be remembered and recognised for his fantastic contribution to the war effort and his legacy to science. A pardon from the Queen is a fitting tribute to an exceptional man.”

Dr Turing died of cyanide poisoning and an inquest recorded a verdict of suicide, although his mother and others maintained his death was accidental.

There has been a long campaign to clear the mathematician’s name, including a well-supported e- petition and private member’s bill, along with support from leading scientists such as Sir Stephen Hawking.

The pardon under the Royal Prerogative of Mercy will come into effect today. The Justice Secretary has the power to ask the Queen to grant a pardon under the Royal Prerogative of Mercy, for civilians convicted in England and Wales.

A pardon is only normally granted when the person is innocent of the offence and where a request has been made by someone with a vested interest such as a family member. But on this occasion a pardon has been issued without either requirement being met.

In September 2009, then-prime minister Gordon Brown apologised to Dr Turing for prosecuting him as a homosexual after a petition calling for such a move.

An e-petiton – titled “Grant a pardon to Alan Turing” – received 37,404 signatures when it closed in November last year. The request was declined by Lord McNally on the grounds that Dr Turing was properly convicted of what at the time was a criminal offence.

S. Barry Cooper, a University of Leeds mathematician who has written about Turing’s work, added the comments below:

This is a historic event, coming just before the 60th anniversary of Alan Turing’s passing in Manchester on June 7th, 1954. The historic injustice can never be undone, but it is wonderful that the Government has officially restored Turing’s reputation, and removed the distraction from his amazing scientific and personal achievements.

There are still thousands of others whose lives were changed forever by the law ‘as it was at the time’. No doubt, having shown that we can be generous and do what is necessary regarding Turing, the situation of others will get more consideration.

All thanks must go to the host of wonderful people who have prepared the ground over the years – one hesitates to mention any names, because there were so many, including subscribers to this list.

But, … many thanks to Andrew Hodges for his truly marvellous biography of Turing – there have been others, with their own special qualities (such as being shorter!), but Andrew’s is one of the all-time great biographies, and has done much to help us understand both man and his thinking.

Both UK Government petitions raised the issue of the conviction. The first, initiated by John Graham-Cummings, leading to the Gordon Brown ‘apology’, was a break-through in our thinking, and brought over 30,000 people into the campaign.

The William Jones petition mentioned by Chris Grayling showed you could do it twice! and get even more signatures, building on John’s initiative and the excitement and world-wide reach of the 2012 centenary celebrations.

And then Lord Sharkey, with his private members bill, and John Leech MP carrying the bill forward to the Commons – and a whole spectrum of MPs from different parties, and other famous figures lending their support.

And finally, Chris Grayling cutting through the formalities with such decisive effect, and with such nice timing.

On the broader front there was a coming together of many different communities. The gay community, mathematicians, computer scientists and scientists from many areas, artists, musicians, creative thinkers and artists of all kinds, many for very personal reasons, some on the autistic spectrum empowered by the iconic example of Turing’s history.

And the international dimension has been fantastic, moving, exciting, generous, and totally engrossing in its variety and interest. And our friends in the media have been great too … the list is a long one.

See also: Enigma codebreaker Alan Turing receives royal pardon

The true meaning of Christmas Ken Perrott Dec 24

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I reckon you can’t beat Tim Minchin’s song “White Wine in the Sun” to convey the real atmosphere of Christmas – at least in Australia and New Zealand.

Here’s a new version – recorded at the Uncaged Monkeys show in Manchester on 6th December 2011. It’s a bit shaky at the start but gets better.

Tim is accompanied by Prof. Brian Cox on keyboard in this version

Tim Minchin & Prof Brian Cox – White Wine In The Sun

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Where is the heat going? Ken Perrott Dec 22

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It is a good article but a lousy headline.  The December 7 issue of New Scientist has a cover head-line Climate showdown: Is it time to stop worrying about global warming? That will create the wrong impression among those many people who get no further than headlines. And it certainly doesn’t convey the message of the article itself.

The article does acknowledge that “the average surface temperature of the planet seems to have increased far more slowly over [recent years] than it did over the precious decades.”

But says:

“This doesn’t mean that climate change has stopped, any more than the very rapid warming seen in the 1990s meant it had accelerated.”

Several reasons

The article a describes several reasons that help explain the current situation. To do this it stresses “it helps to think about heat energy rather than temperature.” In summary:

“In terms of heat. There are three possible reasons why the Earth’s surface temperature hasn’t increased much recently”

  1. Less heat arriving from the sun. “The sun’s heat output rises and falls in an 11-year cycle and measurements by spacecraft such as SOHO show it did dip particularly low recently.”
  2. Increased levels of sulphur aerosols in the atmosphere could have reflected more of the sun’s heat back into space. “Levels of sulphur dioxide have risen in the past decade, mainly due to lots of small volcanic eruptions.”
  3. More of the heat gained by the planet “ends up somewhere other than the lower atmosphere, whose temperature we focus on.”

Ocean – the main culprit

The article points out the most likely storage place for this heat is the ocean.

“Water covers more than 70% of the planet and the stuff has a huge capacity to absorb heat: around 3000 times as much energy is needed to warm a given volume of water by 1°C as is needed to warm the same volume of air.

“Observations show that a whopping 94% of the heat energy gained by the planet since 1971 has ended up in the oceans, with another 4% absorbed by land and ice. . . . So all the surface warming since 1971 is due to just 2 per cent of the heat. If just a little more heat than usual has been going into the oceans, it will have had only a slight effect on ocean surface temperatures, because of water’s huge capacity to absorb heat, but a large effect on atmospheric temperature. And several studies show that the oceans have indeed been soaking up even more heat than normal.”

The article goes on to suggest this is because there have been lots of La Niňas (which cause the Pacific to soak up heat – thus cooling the planet) lately but no major El Niňo (which extract heat from the Pacific to the atmosphere and warm the planet) for the past 15 years.

The graphic from the article illustrates where the heat has gone.


The whole process is obviously complicated and there are various opinions among climate scientists about the relative importance of the different processes distributing heat. There is even a suggestion “that soaring aerosol emissions from China may have contributed to the slowdown” of surface temperature increases. However:

“the mainstream view expressed in the latest Intergovernmental Panel on Climate Change report is that about half of the surface slowdown is due to the oceans, and the other half due to the sun and extra volcanic aerosols.”

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Fluoride debate: Response to Paul’s 5th article Ken Perrott Dec 16

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This is Ken Perrott’s response to Paul Connett’s last article Fluoride debate: Arguments against fluoridation thread. Part 5. Paul.

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

Paul’s last article was another Gish gallop of arguments and questions he demands I answer.  I discussed the use of the Gish gallop as a tactic for avoidance in my last article. In this article Paul demonstrates how the Gish gallop enables the user to also claim their discussion partner is “ducking” issues and “didn’t address,” “didn’t  acknowledge,” “didn’t comment on” or “didn’t respond to” issues he has raised.

Again, I will not walk into that debating trap and mechanically go through his 30 numbered arguments but will attempt to accommodate as much as is reasonable with some general comments and some specific replies.

Activism and science

This year the fluoridation issue raised questions about the problems of activism for a number of New Zealand scientists. The local scientific community was taken by surprise when the Hamilton City Council in June this year voted to end fluoridation. Surprised because most of us were unaware that the council had decided not to go ahead with a referendum (as we had expected) and instead use a “tribunal” process of consultation. This approach suites activist groups very well. They can be continuously in touch with council decisions, have a membership or contact base that can be organised rapidly and they can saturate such a consultation process with their own submissions.

The Fluoride Action Network of NZ (FANNZ) did this very well. They were able to dominate the consultation process with 89% of the total submissions. (This in a city where referenda have shown about 70% support fluoridation). Being part of Paul Connett’s Fluoride Alert Network they did this on an international scale – about 30% of their submissions were from outside Hamilton with many from outside New Zealand. People like Paul Connett and Declan Waugh made video submissions. These people were promoted as “international experts” or “world experts” on the subject even though they have no credible scientific publications on the subject. Of course local councillors did not have the background to see through that ruse. Reports prepared by the council staff showed the number and international origins of these submissions impressed the council and it’s bureaucracy.

It was easy to conclude that what local scientists lacked was a similar organised activist group. If not specifically devoted to defending the science behind fluoridation then at least to defending science in general. After all, anti-fluoridation activity is not the only area where science gets challenged.

Scientists and health professionals did become active in social communication activity, Facebook, letters to the editor, etc., but I noticed a distinct lack of enthusiasm for any organised activism. No one rushed to form an activist group.

Scientists have a problem with activism because the group thinking and selective use of scientific information inevitably involved is in direct conflict with the scientific ethos. That is why activist scientists tend to face disapproval from colleagues, although this has changed a little recently where the vicious personal attacks on individual climate scientists has made some form of scientific activism essential.

Confirmation bias and activism

Contrary to what many people believe humans are not naturally a rational species. Despite their intelligence and ability to reason they are in practice driven primarily by instinct and emotions. In fact, they would have long become extinct if they relied completely and in all cases on the inefficient and slow process of rationally considering every event that required a response.

This means that confirmation bias and cherry picking information come naturally to us. It is normal to seek information which supports the preconceived ideas and theories we are emotionally attached to. Scientists are just as prone to these human failings as others but the scientific processes help reduce this problem. Scientific ideas and hypotheses are tested by experiential evidence – they are compared against the real world. Theories are judged on their evidential support and not their attractiveness. (This does not deny an important role for speculation). Ideas and theories are exposed to harsh critical consideration by colleagues. All this helps to encourage objectively and reliability of scientific information – while not denying that there are still inevitable residual problems from confirmation bias. The dynamic nature of science and the provisional nature of current theories and ideas, means that over time mistakes arising  from these human frailties can be reduced.

Contrast that with the position of activists, even scientific activists. They are inevitably driven by strong ideological or political aims which naturally encourage confirmation bias and cherry picking. But unlike a scientific researcher they exist in an uncritical, or at least biased, social environment. Group thinking encourages a selective approach to scientific knowledge and a resistance to considering anything conflicting with the activist agenda. While heretics can be encouraged in scientific research they get jumped on in activist groups. Ideas and messages do not get tested against reality – far from it. They are tested for political effectiveness, in the political arena – not the natural world.

In effect, the world of activism is stifling for a person used to the creativity of genuine scientific research. I recognise that at times activism is essential and have myself played an activist role in my past. Now I see it as a necessary evil but not something I could do as a job. I do not envy Paul Connett his job as an executive for an activist organisation. The environment of group thinking and the need to abandon intellectual honesty to the ideological aims of the group are bad enough. But what happens to a scientist in such a position who finds they can longer follow the “party line?” That they no longer “have the faith?” It is a bit like the priest who finds, after years in the job ,they are an atheist. Do they go on hypocritically preaching every Sunday or do they take the honest way out and abandon their job with it’s financial and social security to face an uncertian future?

In scientific research it is expected that we can change our beliefs and ideas in the face of new evidence. Not to do so could lead to loss of scientific prestige and employability. It is the reverse to what Paul would face if he lost his anti-fluoridation convictions.

That is the problem for me – the strong pressure to conform to the activist ideological agenda despite the evidence. I think that colours Paul’s approach to many of the issues in his articles here.

Misleading propaganda

Paul raises the misleading image that was in a Queensland Health brochure again. He sweats blood attempting to imply my approval of that tactic. That is not honest. Especially as I made clear that “I do not support its implied message.” And explained that Paul’s Queensland Health example, and a similar anti-fluoridation brochure I raised, are “extreme exaggerations used to promote a message. Reasonable people should condemn that tactic. “

It is interesting Paul devotes so much time on this brochure in his last contribution to what, after all, is meant to be a scientific exchange, not an exercise in laying guilt for someone else’s transgression.  No one is actually defending the Queensland Health brochure – even Queensland Health! At this stage it seems purely to be a plaything of the anti-fluoridation groups. Paul himself was unable to supply a source or citation yet he had ready access to it and promotes it far and wide.

Don’t know what else I can add – except writing personally to Queensland Health with a complaint. Bit difficult without a citation to its use I could quote. Never mind, my public admonishment here should suffice.

I agree with Paul that we should expect better from our public servants but Paul missed my point “This sort of misrepresentation is probably more common among opponents of fluoridation.” I certainly find misrepresentation by public officials on this subject rare –  anti-fluoride activists make this charge far more often than is justified.

I do not buy Paul’s argument that similar but much more common misinformative propaganda by anti-fluoridation activists is somehow more permissible than the rare piece by a public servant. Especially as we have the power to correct a public servant, submit a freedom of information application, get a retraction and an apology. But try that with anti-fluoride activists and organisations like FAN and FANNZ. No such luck. One is more likely to be abused.

Paul’s complaints in this area would be a bit more convincing if he publicly condemned the misleading propaganda from his own activists. He cannot be unaware of the extreme claims made by members of his Fluoride Alert Network throughout the world. Quite apart from their misrepresentation of the science, which he probably encourages anyway, there are the political and personal harassment of people by sections of his activist network which he cannot be blind to, yet refuses to condemn.

I have yet to see him condemn the atrocious propaganda, lies and personal attacks of propagandists like Alex Jones and Vinny Eastwood. It is not enough to say he doesn’t necessarily support all their positions. The fact that he uses their services, and they use his, makes such weak dissociation disingenuous.

Why is he unwilling to publicly condemn such behaviour?

The Hastings trial

Paul weaves a conspiracy theory around the Hastings’ trial using on one-sided sources and their vague claims. I note that Paul also relies on quotes from letters. He does the same in his book. A colleague analysed the reference list and found many are to newspapers, magazines, newsletters, letters and conversations in meetings (a large proportion are duplicates) (see an impressive-sounding number of references, (therefore good?)). Yet he proudly says “You will note that every argument in this book is backed up with references to the scientific literature – 80 pages in all.” 

I don’t think such vague charges should be the subject of our scientific exchange – especially as they divert attention from the scientific issues involved in planning and interpreting such trials and epidemiological studies. Paul should have looked at the disputes around Colqhoun’s analysis of the New Zealand data. Colqhoun was strongly criticised for reliance on questionable data, crude measurements of caries prevalence and failing to establish residence histories and therefore reliable measures of fluoride intake (see, fir example, Newbrun & Horowitz, 2002). He also placed far more reliance on longitudinal studies than is warranted and was selective in choosing studies which have compared fluoridated and unfluoridated communities.

I looked at the current NZ data, which are similar to that analysed by Colqhoun, in my article Cherry picking fluoridation data. This illustrates a number of things. The national data shows clear differences between children from fluoridated and unfluoridated communities and an ethnic effect attributed to social and economic deprivation. This is just normal school clinic data, without technique standardisation for those making the measurements or proper recording of place of residence. The latter effect probably shows up more strongly after 2004 when a “hub and spoke” dental clinics system was introduced further confusing proper records of likely fluoride intake because one clinic could serve a number of areas – both fluoridated and non-fluoridated. This is a likely explanation for the apparent decline of the effectiveness of fluoridation after 2006.

To illustrate how easy it is to extract data for regions and cities which give meaningless results the plot below shows the data for the Waikato. Clearly the variability in this data, (indicated by abrupt changes year to year) is so large it make interpretation meaningless. Yet this does not stop FANNZ, the local version of Paul’s activist organisation, from hypocritically using just the 2011 data for the Waikato (where by chance children from fluoridated areas show more caries than unfluoridated!). One of their representative end used my graph below, showing the problem of cherry picking, as “proof” for claiming fluoridation increases incidence if caries. During the recent referendum campaigns this misrepresentation by anti-fluoridation activists was rife – yet they consistently ignored or covered up the national data.

There is a lesson in this. Careful and critical analysis of epidemiological data is necessary when considering such data. Effects of technique standardisation and changes, places of residence, mobility of families and diffusion of products from fluoridated into non-fluoridated areas must be considered.

Too often anti-fluoride activists simply select the data that fits their story better. They may even be unaware of what they are doing because confirmation bias is a trap we can all fall into and it can be very tempting if one is simply looking for plots to illustrate an effect. To be fair, I have even seen proponents of fluoridation fall into this trap occasionally.

Margin of safety

Paul mentions margin of safety a lot. He claims that I did not comment on the margin of safety analysis he provided based on the Xiang et al. (2003a,b) study.

Has he not been reading my side of the exchange?

I had put a question to him on his use of this study to determine a margin of safety. After commenting on the quality of the study and the journal Fluoride where it was published I wrote:

Yet Paul uses Xiang’s paper to authoritatively claim it had “found a threshold at 1.9 ppm for this effect.” (What effect he refers to is unclear.) How reliable is that figure of 1.9 ppm (actually 1.85 or 2.32 ppm F in the paper) –  considering the huge variation in the data points of the Figure 1? (Unfortunately the paper is not a lot of use in explaining that figure – reviewers should have paid more attention.)”

Paul did not respond so I repeated my question in a subsequent article asking him “about the huge variability in the data and how the hell one can place any confidence on the result drawn from Xiang’s figure.”

Briefly my question related to the figure used by Xiang et al.


This is just another example Paul’s selective use of the literature and selective interpretation of parts of it to justify a preconceived claim he wishes to make. In practice, safety limits and margins of safety must be based on a far more extensive review of the literature and involve far less hand waving than Paul demonstrates in this case.

Bottle fed babies – misinformation again

Several times Paul has raised the issue of bottle-fed infants without describing the problem. Broadly, he is making the common anti-fluoridation claim that the reliance of bottle-fed infants on formula made up with fluoridated water causes normal limits for maximum F intake to be exceeded. Usually activists using this argument will refer to health authorities which they claim recommend that formula not be made up using fluoridated water.

The science for the New Zealand situation is clearly described by Cressey et al (2009) in their report Estimated Dietary Fluoride Intake For New Zealanders by Peter Cressey, Dr Sally Gaw and Dr John Love. It is a straightforward desktop study of the “dietary fluoride intakes for a range of age and gender sub-populations based on New Zealand data.” This is how they described their findings for formula-fed infants:

“The estimates for a fully formula-fed infant exceeded the UL [upper level of intake] approximately one-third of the time for formula prepared with water at 0.7 mg fluoride/L and greater than 90% of the time for formula prepared with water at 1.0 mg fluoride/L. However, it should be noted that the current fluoride exposure estimates for formula-fed infants are based on scenarios consistent with regulatory guidelines, rather than on actual water fluoride concentrations and observed infant feeding practices..”

They conclude “the very young appear to be the group at greatest risk of exceeding the UL.” However:

“the rarity of moderate dental fluorosis in the Australia or New Zealand populations indicates that current exceedances do not constitute a safety concern, and indicates that the UL may need to be reviewed.”

They are conceding that in some cases, some of the time, recommended upper levels for fluoride intake can be exceeded for fully formula fed infants. However they do not see this as a real safety concern.

These conclusions lie behind the current advice from our Ministry of Health on this subject. This takes account of the need for review of current ULs and considers use of fluoridated water safe for fully formula-fed infants. However, they also recommend that if parents are concerned (such as over the risk of dental fluorosis) they should use non-fluoridated water for part of the feeding – a peace of mind matter.

The situation in the US is similar

American Dental Association advises:

Yes, it is safe to use fluoridated water to mix infant formula. If your baby is primarily fed infant formula, using fluoridated water might increase the chance for mild enamel fluorosis, but enamel fluorosis does not affect the health of your child or the health of your child’s teeth. Parents and caregivers are encouraged to talk to their dentists about what’s best for their child.”

Where parents want to reduce the risk of dental fluorosis they:

can use powdered or liquid concentrate formula mixed with water that either is fluoride-free or has low concentrations of fluoride.

And the CDC advises:

Yes, you can use fluoridated water for preparing infant formula. However, if your child is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance for mild dental fluorosis. To lessen this chance, parents can use low-fluoride bottled water some of the time to mix infant formula; these bottled waters are labeled as de-ionized, purified, demineralized, or distilled.

This sort of information is often distorted by anti-fluoridation activist propaganda. Very often they claim that authorities like the CDC are recommending as an absolute that parents use non-fluoridated water in preparing formula for infants, and not treat the issue as a peace of mind matter.

Dental fluorosis

Anti-fluoridation activists almost unanimously quote figures for total dental fluorosis (or its equivalent) lumping together everything from questionable to severe. This gives them a nice high figure to promote. But, as I have said before, they use a bait and switch tactic to exaggerate the seriousness of the problem by then considering only the more severe category’s when considering the harm. It is worth actually listening to the anecdotal evidence of practicing dentists on this specific issue. How often do they see fluorosis or similar blemishes which need treatment? And how does this figure compare with the frequency with which they see dental decay serious enough to need treatment? I can think of only one dentist who claims fluorosis is a problem which he often sees and treats – he is an active propagandist for FANNZ. I have caught him telling many porkies about fluoridation and I wouldn’t trust his claims.

Paul attempts to put words in my mouth saying I “claimed there was practically no difference in dental fluorosis prevalence between fluoridated and non-fluoridated communities.” I did point out that the most recent NZ Oral Health Survey found no measurable difference. But I also acknowledged that in general an increase in mild categories is normally observed with fluoridation. What I actually wrote was:

“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.”

This is not a denial of an increase in mild forms of fluorosis as a result of fluoridation. Nor is if a denial that the relatively small difference may reflect the diffusion of the benefits of fluoridation into the non-fluoridated areas through family mobility, poor representation of residence history and the movement of products prepared with fluoridated water.

Paul’s misrepresentation is not the sort of behaviour I expect from a discussion partner in a scientific exchange.

All Paul’s manipulation of figures and his claimed access to the minds and “potential psychological problems for young teenagers” does nothing to change the basic situation. This is that water fluoridation can cause an increase in the mildest classification of dental fluorosis but is generally not thought responsible for the more severe classifications. The later are relatively rare and any increases over recent years is unusually attributed to the wider use of fluoridated toothpaste and fluoride dental office treatments (and their accidental ingestion).

The common anti-fluoridation propaganda gives the impression that the total fluoridation occurrence quoted is all severe and not almost all very mild or questionable. For example, in New Zealand activists often use the figure of 44% occurrence of dental fluorosis when only 2.5% is of any concern.

Selective quoting

I have said again and again that one should attempt to understand the scientific literature intelligently and critically. Hard to do as we all suffer from conformation bias and can’t help being selective. Fortunately working within a scientific community there is pressure from peers who will challenge ones interpretation. This helps encourage objectivity and honesty.

But working in an activist group one does not experience such challenges. If anything there is the challenge to conform with the group thought. Confirmation bias and cherry picking gets encouraged and rewarded. Paul’s activism and bias is very clear in the way he selectively quotes the NRC (2006) report. Just a few examples from his last article in his attempt to justify conclusions he wishes to draw from animal studies using high fluoride concentrations.

“Dunipace et al. (1995) concluded that rats require about five times greater water concentrations than humans to reach the same plasma concentration. That factor appears uncertain, in part because the ratio can change with age or length of exposure. In addition, this approach compares water concentrations, not dose. Plasma levels can also vary considerably both between people and in the same person over time (Ekstrand 1978).” (My emphasis of the bits Paul omitted).

Similarly with Paul’s second quote from the NRC report:

Because many assumptions were involved in estimating the values presented in Table D-2, they should be used with caution. But values support a rat-to-human conversion factor for bone fluoride uptake of at least an order of magnitude.” (My emphasis of the bits Paul omitted).”

Natural and artificial fluoride

Many of people relying on Fluoride Alert for their information are confused about the nature of the hydrated fluoride anion in water. At the mystical end of this confusion is the concept that chemical species derived from man-made process are different in their biological action to that from natural sources, even though chemically there is no difference. At the more “realistic” end there is a refusal to accept that the fluorosilicate anion decomposes on dilution. Then there is the hand waving over the role of calcium that Paul indulges in. He repeats his claim:

“Usually when fluoride occurs naturally in the water it is accompanied by large concentrations of ions like calcium. The presence of the calcium can reduce the uptake of fluoride in the stomach and GI tract. No such protection is offered when the fluoridating chemicals are added to soft water.”

I have had to repeatedly battle out this argument with anti-fluoridation activists who obviously don’t understand basic chemistry but I find this statement amazing for a chemist who should understand the concept of solubility products and the nature of ions in solution.

Contrary to Paul’s suggestion the relationship observed between natural Ca and F concentrations in groundwaters is usually inverse – F concentrations increase as Ca concentrations decrease and vice versa (see for example Handa 1975Geochemistry and Genesis of Fluoride-Containing Ground Waters in India).  Just what we expect when a solid phase like fluorite or apatite is determining solution concentrations at equilibrium.

Here is what one of the commenters on Paul’s last article, Jo Lane, has to say about Paul’s denial of the presence of Ca in treated fluoridated water:

“Point 20 ) Classic example of pseudoscience. Let’s assume that Paul is correct in asserting that the presence of Ca2+ ions affects F- uptake in the GI tract.

Municipal water supplies in NZ have a target hardness (combined concentration of Ca2+ and Mg2+ ions) of 200 mg L-1. Most of this is Ca2+ as Lime (CaO) is typically used to increase pH in one of the final stages of water treatment.

If water was fluoridated to 0.8 mg L-1 F- (unreasonably assuming there is 0 mg L-1 F- to start with) using CaF2 as a source, the concentration of Ca2+ would increase by 0.2 % as compared to using HFA or NaF as a source of F-. This 0.2% change in Ca2+ concentration will not have any appreciable effect on F- uptake in the GI tract.

Given Paul has a PhD in chemistry I cannot believe that he is ignorant of such basic chemistry and so I am left with the unfortunate impression that he is being deliberately deceptive in the way that he presents his arguments.”

I agree. Sure, the Ca concentration in community water supplies will generally be lower than the target value (which is a maximum) but the principle remains. Replacement of fluorosilicic acid by fluorite (CaF2) as a fluoridating agent would have a minuscule effect on calcium concentrations because there is plenty of calcium from other sources – even is soft water.

Paul’s claim is the sort of thing that even an educated chemist might say if they are ideologically driven. This is the problem with activist groups with their own ideological demands and group thinking. It is easy for even the trained person to fall in to an opportunist use of their speciality. And if, like Paul, they are working as an executive of an activist group they don’t have anyone around them to challenge such distortions.

Irish data and reliance on inter-country comparisons

I am pleased Paul admits to being “hasty” in his dismissal of the Irish data. But there are two issues.

1: His problem was more than haste – I was objecting to his attempt to belittle the data by suggesting the Irish workers were biased. I expressed surprise that he would reject the data with that suggestion in a scientific exchange.

2: He appears confused – despite my clear explanation of the data I used. These was the same as used by Cheng et al (2007) – for just one country (Ireland) but separated into the fluoridated and unflouridated areas – not just using the average that Cheng et al used). Paul describes the data as “comparing tooth decay in the Republic of Ireland and Northern Ireland.” Clearly it did not.

Perhaps Paul’s fixation with Declan Waugh’s discredited comparisons of the health statistics for the two countries was pro-occupying Paul’s mind – or perhaps he wanted to divert the discussion into that area.

I repeat the comparison I used below.

The dotted line in the RH figure is effectively what Cheng et al (2007) used for Ireland in the LH figure.

At the time I explained the problems in making the inter-country comparisons Paul was insisting on:

“Simple comparison of countries obscures all sorts of effects such as differences in culture, history, social and political policies, etc. Such plots are also influenced by changes and differences in dental treatment and measurement techniques.”

However, as Paul raises the issue again it is worth commenting again on the flippant way he and other anti-fluoridation propagandists use inter-country comparisons like this. This is the hand-waving involved in claiming the data shows no effect of different fluoridation policies. I will use a figure from Paul’s book to illustrate the problem.

Paul claims his figure shows no difference between the countries – but did he do anything to check that? Did he actually measure the slopes for the different countries? Or did he just wave his hands and say there is clearly no difference?

Fortunately with so few countries it is relatively easy to compare the slopes. I have done so using the data from the WHO site and found the average decline was 0.17 DMFT/year for fluoridated countries and 0.13 DMFT/year for the non-fluoridated countries. This suggests the decline of DMFT in the fluoridated countries was about 25% greater than in the non-fluoridated countries.

Local anti-fluoridation activists reacted strongly to my analysis claiming it is obvious that the analysis is useless. I am sure Paul will point out that the figure of 25% will not be statistically significant – and I agree. The scatter in the rates of decline among the different countries is very large. On top of that the original data itself is hardly very good with generally only 2 data points for each country.

But if the variation is great enough to make a 25% difference in slopes non-significant then what value do such figures have for Paul’s argument? Using simple hand waving and eye-balling to claim no difference is deceptive because he hides that variation. We just don’t expect such comparisons to show the differences due to fluoridation policies. Variation and the influence of confounding factors have too great an influence.

Paul continues to ignore systemic role

Although he concedes it wrong to create the impression that the current surface or topical mechanism for the beneficial role of fluoridated water on existing teeth is the only mechanism he still persists in ignoring any role for ingested fluoride. Any systemic effect. He asks “why are we forcing people to swallow fluoridated water at all?” He ask why I am “not merely advocating swishing and spitting out fluoridated water, or fluoridated mouthwash or using fluoridated toothpaste.”

I have answered that question several times but Paul continues to ignore my response. He claims my  description of the normal and natural role of fluoride in bioapatites do not get is anywhere. He ignores my reference to scientific reports of the participation of ingested fluoride in improving oral health, especially through its beneficial role before teeth erupt.

Unfortunately Paul cannot get past his emotive description of a social health policy as “forcing” something on people. His naive assertion that normal consumption of water should be replaced by “swishing and spitting out” or by a mouthwash or toothpaste also shows he just does not understand the nature of a social health policy. I discussed this in more detail in my last article.

Hirzy’s conspiracy theory

Paul’s colleague in FAN, Bill Hirzy, is unhappy about my reference to his use of a conspiracy theory – the claim that fluoridation is used as a way of disposing of industrial waste. I was referring to Bill’s claim in his section of Paul’s article:

“Water fluoridation, especially with FSA in the U.S., is not at all about improving dental health; it is rather about U.S. taxpayers paying phosphate producers billions of dollars for the privilege of having our public drinking water systems used to dispose of an acid that would otherwise have to be managed in a hazardous waste facility, and thereby improving the bottom lines of phosphate producers.”

He defends himself by attempting a diversion into USGS data showing 94% of fluoroslicic acid produced as a byproduct by phosphate manufacturers goes to water fluoridation systems.

I don’t doubt those figures. M. Michael Miller, in his article Fluorspar gives similar data for 2004:

“About 38,700 t of byproduct fluorosilicic acid valued at $5.15 million was sold for water fluoridation, and about 1 2,300 t valued at $2.71 million was sold or used for other uses”

Miller’s 75% of byproduct fluorosilicic acid sold for water fluoridation is lower that the 94% Hirzy quotes but the difference could result from some of the material being converted to other products before sale.

So, if a quarter of byproduct fluorosilicic acid, or its conversion products, find markets other than water fluoridation what is it about this quarter which makes it a valuable, saleable product – while the 75% sold for water fluoridation must be classified as a waste product and need a conspiracy for its disposal?

Extensive possibilities for fluorosilicic acid uses

As mentioned above there is certainly a market for fluorosilicic acid,and it’s conversion products, apart from use as a water fluoridation agent. I believe that market will probably increase further because the decline in fluorite sources will increase the use of phosphate ores as a source of fluorine chemicals. This will mean that fluorosilicic acid will become more commonly used as an intermediate in the preparation of many, if not most, fluoride chemicals produced.

Currently fluorosilicic  acid can be used in the tanning of animal hides and skins, oil well acidifying, electroplating, glass etching, as a commercial laundry sour,  sterilising agent, in cement and wood preservatives, in the manufacture of ceramics, glasses and paints, in lead refining, etc. it can also be used to manufacture hydrofluoric acid, another important industrial chemical and intermediate for many other fluorine compounds. It can also be converted to aluminium fluoride and cryolite which are important  in the   conversion of alumina ores to aluminium metal.

Ultimately the fluorosilicic acid byproduct from the phosphate industry could become the Teflon on your frying pan, the refrigerant compound in your refrigerator or incorporated in the many products you use every day.

Anyone wanting to follow the debate and/or check back over previous articles in the debate can find the list of articles at Fluoride Debate.

See also:

Similar articles on fluoridation
Making sense of fluoride Facebook page

Back to the moon! Ken Perrott Dec 15

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Well, this is pretty historic!

China has successfully soft landed its probe on the moon and the rover is now on the surface.

The Planetary society’s Emily Lakdawalla has posted TV video of the unloading of the Rover – see Six wheels on soil for Yutu!

These are 3 animated gifs from Emily’s article

20131214_change3_rover_deploy_final 20131214_change3_rover_deploy_2_transfer 20131214_change3_rover_deploy_1_roll

For those wanting to follow the process in real-time this is the video from the TV coverage.

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Fluoride debate: Arguments Against Fluoridation Thread. Part 5. Paul Ken Perrott Dec 12

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This is Paul Connett’s response to Ken Perrott’s last article  The fluoride debate: Response to Paul’s 6th article.

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

Here is my response to Ken’s last response to this thread (part 4).

Propaganda from Queensland Health

 1) The pictures below appeared on page 2 of a 4-page leaflet from Queensland Health used to promote mandatory fluoridation in 2007. It compares pictures of the teeth of a child who has had its teeth “exposed to fluoridated water” (beautiful) with the teeth of a child “without exposure to fluoridated water” (atrocious).

QLD Health brochure

In response to this figure Ken writes:

  “It seems to have been taken from a document prepared under the Queensland Health logo. I cannot find a source and no-one seems to be able to give a citation. It is not on the Queensland Health web site.” (my emphasis)

Why does Ken say “seems”? I forwarded a copy of the whole leaflet to Ken. Does he doubt the authenticity of that leaflet?  I have no doubt at all about its authenticity.  Mind you, I am not surprised – now that citizens in Queensland have pointed out this outrageous piece of state-funded propaganda – that Queensland Health is embarrassed and should want to hide all traces of it.

2) I think it was disingenuous of Ken to try to nullify this outrageous propaganda by providing a link to a leaflet produced by an anti-fluoridation group. The point I was making (in part 3 of this thread – originally part 1A) is that it is one thing for citizens – either promoters or opponents – to use tactics like this (I certainly do not condone or endorse any side using such tactics) but it is quite another when bureaucrats working for the state and paid by taxpayers to protect their health stoop to such tactics. It is unacceptable. Nor should it be necessary if this practice was as “safe and effective” as the promoters claim. Surely the role of civil servants is to provide objective information on a controversial issue not side with one side and then provide outrageous spin in support of that side.

3) Ken did not respond to my other concerns about the propaganda used by Queensland Health. This is less dramatic perhaps but equally deceptive. This was their claim in newspaper ads (see picture below) that there was a 65% difference in tooth decay between fluoridated Townsville and non-fluoridated Brisbane (see picture below).

Newspaper ad

To get this 65% reduction Queensland Health had selected the number for the relative difference for just one age – 7 year olds.  In Table 4 – in the paper by Slade et al.,  (see below) readers will see that this 65% relative reduction amounted to an absolute saving of a measly 0.17 of one tooth surface. Their arithmetic is accurate but a 65% reduction sounds a whole lot more impressive than a saving of 0.17 of one tooth surface. This is a deliberate attempt to mislead the public. In other words, it’s PR spin. I would be interested to hear how Ken would describe it.


Returning to the photographs in the Queensland Health brochure, does the difference in these two sets of teeth look like a difference of 0.17 of one decayed, missing and filled permanent tooth surfaces (DMFS)?

I wish I could say that this blatant propaganda on behalf of personnel at Queensland Health is an aberration among civil servants in the health agencies of the countries practicing fluoridation. Sadly, from my personal experience, it is not.

I have seen first hand outright propaganda from people at the highest levels of civil service in the health agencies of several fluoridating countries as well as their minions in their bureaucratic chain of command.

The propaganda of these civil servants is shameless but sadly gobbled up by the media and too many local decision makers in their respective countries. One would have hoped that scientists like Ken Perrott with their sensitive antenna to scientific misrepresentation would have helped expose this sad state of affairs. Instead of doing this they fire their rhetorical guns at the citizens who are doing their very best – with limited resources – to bring this state-financed propaganda to the attention of the media, the public and their political representatives – but it is an uphill job.

4) In NZ the manipulation of the science on this practice goes back a long way – in fact to the very first trial of fluoridation in Hastings (with Napier as the control city). This trial was carried out from 1954 to 1964 and has been shown by the late Dr. John Colquhoun and his PhD thesis advisor Dr. Robert Mann and others to have been a scientific fraud (Colquhoun and Mann, 1986; Colquhoun, 1987 and Colquhoun and Wilson, 1996).

5) Ken might wish to comment on the following candid letter sent out by the Director of the Division of Dental Health, Dr. G. H. Leslie, in 1962 – some eight years into this 10-year trial.


I have typed out this letter to make it easier for people to read, as some of the letters are not clear:

 Mr. Swann,

 I have delayed acknowledging receipt of Dr. Roche’s letter to you and replying to your minute in the hope that I would by now be able to give a positive reply to your enquiry. I still cannot.

 No one is more conscious than I am of the need for proof of the value of fluoridation in terms of reduced treatment. It is something which has been concerning me for a long time. It is only a matter of time before I will be asked questions and I must have an answer with meaning to a layman or I am going to be embarrassed and so is everyone else connected with fluoridation. But it is not easy to get. On the contrary it is proving extremely difficult. Mr. Espia is conferring with Mr. Bock and Mr. Ludwig and I am hopeful that in due course they will be able to make a practical suggestion.

 I will certainly not rest easily until a simple method has been devised to prove the equation fluoridation = less fillings


(G.H. Leslie)


Division of Dental Health

 6) With this letter we have what amounts to a “smoking gun” as far as the inability of NZ  dental officials and researchers to show the effectiveness of fluoridation – some eight years into the ten-year Hastings-Napier fluoridation trial.

7) However, miraculously, two years later this trial was proclaimed as a great success at demonstrating that fluoridation had led to a large reduction in tooth decay (over 60%) and the result was used to push for fluoridation throughout the country.

8) So how in the space of two years was this dramatic turnaround achieved?

9) According to Dr. John Colquhoun’s research it was a complete artifact. The deception was in three parts. First, after about two years the control city of Napier was dropped for bogus reasons. Two, the reduction in tooth decay claimed was based on comparing tooth decay in Hastings at the beginning and the end of the trial (and not a comparison between tooth decay in Hastings and Napier).  Three, method of diagnosing tooth decay was changed during the trial. Colquhoun describes this third aspect of the deception:

The school dentists in the area of the experiment were instructed to change their method of diagnosing tooth decay, so that they recorded much less decay after fluoridation began. Before the experiment they had filled (and classified as “decayed”) teeth with any small catch on the surface, before it had penetrated the outer enamel layer. After the experiment began, they filled (and classified as “decayed”) only teeth with cavities, which penetrated the outer enamel layer. It is easy to see why a sudden drop in the numbers of “decayed and filled” teeth occurred. This change in method of diagnosis was not reported in any of the published accounts of the experiment.”

What qualifies these activities as scientific fraud, in my view, is the last sentence: “This change in method of diagnosis was not reported in any of the published accounts of the experiment.”

 10) To the best of my knowledge the evidence that Colquhoun and Mann put forward for this rigged trial has never been refuted. I would be anxious to see if Ken can throw a different light on this matter. If he can’t then I think that he and other NZ citizens should be concerned that the people of NZ were duped in this way.

Ken was unresponsive to many of my other concerns expressed in parts 1 and 1A (or parts 1 and 3 in my thread, The Arguments Against Fluoridation).

11) Ken didn’t address the key issue of the difference between concentration and dose when comparing artificially fluoridated communities and naturally fluoridated study communities when harm has been identified.

12) He didn’t address the need for a margin of safety calculation when determining a safe dose for a community based on a human study that has found harm (see chapter 20 in The Case Against Fluoride…). Nor did he comment on the sample margin of safety analysis that I provided based on the Xiang et al. (2003a,b) study, although he has commented on the Xiang study elsewhere.

13) He didn’t comment on my response to his claim – that there was no need to control the dose as far as efficacy was concerned because it worked over a wide range. I pointed out that there was not a wide range as far as safety was concerned and gave this information:

“I would also remind you that when the US National Research Council reviewed the toxicology of fluoride in water they concluded that several subsets of the US population were exceeding the US EPA’s safe reference dose for fluoride (the so-called IRIS value) of 0.06 mg/kg/day. This included high water consumers and bottle-fed infants. See Figure 2.8 in their report (NRC, 2006).”

14) Ken is ducking a key issue when he writes:

“It is pointless to continue debating definitions of fluoride as a medicine – as I have said the argument is largely semantic. People who wish to pursue the argument should do so in a court of law.”

Is he suggesting that in order to get a rational response from him on this matter I have to take him to court? Joking apart, surely he can concede that the purpose of fluoridation is to treat people as opposed to treating the water to make it safe or palatable to drink? And if he is willing to concede that then doesn’t treating people – at least in some countries – require that those treated have the right to informed consent to that treatment? This is not just about semantics it is about fundamental human rights.  See the definition of medicine and medical treatment under EU law which I provided in the other thread (part 6).

15) Instead of providing me with examples of statements from countries in Europe that have rejected fluoridation for reasons other than the two main ones I cited, Ken fobs me off with a statement from the NZ National Fluoride Information Service. In this statement this body gives no specific examples of countries that have not fluoridated for the reasons it – or Ken – states. So I will ask him again.

Ken please provide some evidence that countries have not fluoridated for the reasons you have given as opposed to the reasons I have given, namely: they do not wish to force fluoridation on people who don’t want it and they argue that there are unresolved health concerns about the practice.

16) When Ken restates that:

“For the vast majority of people who have dental fluorosis (recognised by a professional) it is usually classified as “questionable” or “mild.” Real health concerns should only be raised for severe dental fluorosis. Yet anti-fluoride activists lump all those grades together and pretend that dental fluorosis is a much bigger problem than it really is.”

Ken has essentially ignored all the information I provided for him on this issue. I provided the figures cited by the CDC (2010) for dental fluorosis for children aged 12 to 15 in the US. In this report, they indicate that very mild dental fluorosis impacts 28.5% and mild dental fluorosis impacts 8.6% of the population in question. Mild dental fluorosis affects up to 50% of the tooth surface and presents potential psychological problems for young teenagers. Ken may not consider that a “real” problem but many teenagers do. Ken might also be interested to know that Trendley Dean, the so-called father of fluoridation , who developed this first classification of dental fluorosis in the 1930s, in testimony before the US Congress stated that mild dental fluorosis was an unacceptable trade-off for reduction in tooth decay (see chapter 11 in The Case Against Fluoride…).

Moreover 3.6% of US children aged 12-15 have dental fluorosis in either the moderate or severe category. In these categories 100% of the enamel of the impacted teeth is impacted. Neither of these categories is desirable. 3.6% of all the children aged 12-15 in the US is a lot of children!

17) Ken also claimed that there was practically no difference in dental fluorosis prevalence between fluoridated and non-fluoridated communities. He ignored my response. I cited the study by Heller et al (1997), which clearly showed that that was not the case. They found that as the fluoride levels rose from a) less than 0.3 ppm, to b) 0.3 to 0.7 ppm , to c) 0.7 – 1.2 ppm and then d) above 1.2 ppm there was a marked increase in dental fluorosis rates.

18) I offered an animal study (Varner et al, 1998) in which rats were exposed to 1 ppm fluoride (administered either as AlF3 or NaF) for one year and experienced harmful effects.  I provided this reference because Ken stated that he paid no attention to animal studies performed at high concentrations and that was all he was offered by opponents of fluoridation. However, I got another brush off from Ken.  He claimed that he couldn’t find the whole study by Varner et al – only the abstract – and after a few words on the abstract then stated, “I won’t comment further on this.” First, of all I am surprised that no University in the Hamilton area carries the journal Brain Research where the Varner paper appeared. Also if Ken was having trouble finding this all he had to do was email me and I would have forwarded him a pdf copy of this paper. For future reference I would be happy to do that for all the papers I cite.

19) Nor did Ken respond to the discussion in which I pointed out that the US Food and Drug Administration classifies fluoride for ingestion as an “unapproved drug.” This means that in the U.S. fluoride intended for ingestion has never been subjected to the double blind randomized control trials (RCT) for efficacy that are required of all other drugs. Nor is the FDA tracking side effects from patients or doctors, despite the fact that many individuals claim to be highly sensitive to fluoride’s toxic effects. The same professional and regulatory neglect appears to have occurred in all other fluoridated countries, including New Zealand.

Note: I have raised more specific questions about this professional and regulatory neglect in my latest response (part 6) in the other thread.

20) Ken claimed (in part 2 of this thread) that there was no difference between naturally fluoridated water and artificially fluoridated water and I responded in part 3 that:

“Usually when fluoride occurs naturally in the water it is accompanied by large concentrations of ions like calcium. The presence of the calcium can reduce the uptake of fluoride in the stomach and GI tract. No such protection is offered when the fluoridating chemicals are added to soft water.”

Ken did not acknowledge this important difference.

21) In my response (part 3 of this thread) I wrote:

“In my opening statement I singled out three subsets of the population that shouldn’t be getting fluoridated water: bottle-fed babies, people with poor kidney function and people with outright or borderline iodine deficiency. Ken chose not to comment on the latter two groups. In my view we should be concerned about both groups whether they are drinking naturally occurring fluoride or artificially fluoridated water.”

For the second time Ken chose not to respond to these concerns. Ken is certainly very sensitive to the treatment of low-income families because of his own personal history but he seems not to be as sensitive to the fate of these subsets of the population.

22) Ken chose not to respond to this question:

“Is it not reckless then to knowingly expose the bottle-fed baby to 175-300 times more fluoride than the breast-fed baby? Especially, when we know that fluoride can harm at least one developing tissue in the baby – the growing tooth cells – at very low levels and cause the condition known as dental fluorosis.  What makes us believe that while the fluoride is damaging processes in the growing tooth it is not doing the same to the growing bone. After all the teeth grow out of the bone.”

23) Ken chose not to respond to the following information:

“Even when some warning signals emerged during the early trials they were cavalierly ignored by those hell-bent on promoting this practice. For example, when Schlesinger et al., 1956, published the results of the Newburgh-Kingston trial in 1956 they reported that young girls in the fluoridated community were menstruating 5 months earlier on average than the girls in the non-fluoridated community, and that the young boys were experiencing about twice as many cortical bone defects in the fluoridated community compared with the non-fluoridated community. However, no follow-up studies were recommended (see Chapters 9 and 10, The Case Against Fluoride…). These red flags were ignored then just as the studies indicating a lowering of IQ associated with fairly modest levels of fluoride exposure, are being ignored or downplayed by proponents today.”

24) Ken chose not to respond to Dr. Hardy Limeback’s discussion of possible ways that fluoride can interfere with normal bone growth:

“Bone can ACCUMULATE up to 2500 ppm fluoride with fluoridation (we showed that in our Toronto vs Montreal study). The osteoclast cells are exposed to these huge concentrations (because they dissolve bone keeping the dissolved mineral under their dorsal surface through the use of hemidesmosome attachments and then they release that dissolved mineral into the bone extracellular fluid where nearby osteoblasts can also be exposed). In fact one of the theories why there is apoptosis of osteoclasts is the poisonous conditions they have to endure remodeling bone. It is also the reason there is a biologically-supported rationale for the bone cancer inducing effects of fluoride (personal correspondence, Nov 1, 2013).”

Now I will attempt to respond to some of the issues that Ken did comment on.

25) I agree with Ken that I was a little hasty in dismissing the Irish data comparing tooth decay in the Republic of Ireland and Northern Ireland. However, the larger point I was making was this: if indeed it is legitimate to compare these two populations (and there are both cultural and genetic differences) then the more urgent need is to compare the status of various health concerns – which may or may not be caused by or exacerbated by fluoride – between the two countries. However, even though fluoridation has been mandatory in the Republic since 1963, the health authorities there have not attempted a single study comparing the health of communities which are fluoridated and non-fluoridated, either within the Republic itself or between the Republic and the North. Like most fluoridated countries (including NZ) they are flying blind on health concerns.

26) I think the value of comparing tooth decay between countries is to note that tooth decay rates have been coming down in both fluoridated and non-fluoridated countries at similar rates. Avid promoters of fluoridation such as the Oral Health Division of the CDC often forget this and try to claim that fluoridation has been coming down in fluoridated countries because of fluoridation when similar declines have occurred in non-fluoridated countries over the same period. See the CDC’s ridiculous Figure 1 in CDC (1999),  (see figure below) which purports to show that tooth decay in 12-year olds has come down in the US over the period 1960s to the 1990s because over the same period the percentage of the US population drinking fluoridated water has increased!

Fig1 connett I urge readers to compare this CDC figure with the figure summarizing the decline in tooth decay in many different countries – both fluoridated and non-fluoridated countries – covering the same period (and beyond) cited by the CDC.

fig2 connett

27) I agree with Ken that whenever we cite the CDC (1999) statement that fluoride’s predominant mode of action is topical not systemic we should not omit the word predominant. I usually do this. He found one example when I didn’t.

28) I have conceded in another post that I was wrong in suggesting that Ken believed that the delivery of fluoride’s topical effect was via the saliva generated in the salivary gland. However, if Ken rules out a significant role for the fluoride delivered by the salivary gland, and instead that the topical action is delivered directly in the mouth, why are we forcing people to swallow fluoridated water at all? Especially adults where no tooth development is involved once their teeth have erupted? Why instead, is he not merely advocating swishing and spitting out fluoridated water, or fluoridated mouthwash or using fluoridated toothpaste.

30) In challenging Ken’s notion that the only animal studies we quoted had very high fluoride levels. I responded that it was well known that you needed to treat rats with 5 to 10 times as much fluoride to reach the same plasma levels as humans.  Ken responded by pointing out he could find only one reference to this and cited the NRC (2006) commentary on Dunipace’s work (Dunipace, 1995). The NRC characterized Dunipace’s conclusion as showing that “rats require about five times greater water concentrations than humans to reach the same plasma concentration.” (Appendix D, p. 442). However, there are several other studies that have suggested the same or even a higher ratio than 5 is needed.

Sawan (2010) explains why he used 100 ppm in his animal experiment as follows:

“However, while the fluoride concentration used in the present could be considered relatively high for rodents (100 mg/L or ppm), this concentration was chosen because it produces plasma fluoride levels that are comparable with those commonly found in humans chronically exposed to 8mg/L of fluoride in the drinking water, which is a concentration known to cause severe fluorosis.”

That is a ratio of 12.5.

Also Angmar-Månsson and Whitford (1982) pointed out to produce enamel fluorosis in rats one needed a concentration of 10 to 25 ppm fluoride (compared to the 2 ppm needed in humans). So that means you need a ratio of 5 to 10+ more fluoride to get the same result in rats as humans.  Here is the quote:

“It is well known that, in fluoridated drinking water studies with rats, a water fluoride concentration of 10 – 25 ppm is necessary to produce minimal disturbances in enamel mineralization. Because of the higher water concentrations required, the rat has been regarded as more resistant to this adverse effect of fluoride. However, when the associated plasma levels are considered, the rat and the human appear to develop enamel fluorosis at very nearly the same fluoride concentrations.”

I would also point out that, in addition to the extra amount needed to reach the same plasma levels in humans, the NRC pointed out in their 2006 report that rats need at least 10 times more fluoride than humans to reach the same bone fluoride levels. To quote:

” …values support a rat-to-human conversion factor for bone fluoride uptake of at least an order of magnitude.” (Appendix D, p. 445)

Dr. J. William Hirzy.

31) Ken uses dentist Steve Slott to categorize Dr. Hirzy in the following manner, “Hirzy is a long time avowed antifluoridationist and is employed by Connett as the paid lobbyist for Connett’s antifluoridationist group, FAN.”

Clearly this comment from Slott, “an avowed profluoridationist,” is meant to throw doubt on the credentials and integrity of my colleague Bill Hirzy. I have known Bill for over 15 years. I first met him when he was working at the US EPA. At that time he and other professionals at the EPA were very concerned about the way that administrators in this agency felt that it was OK to force professionals to “bend their science and their statements” to fit into their policy judgments.

This concern began in 1985 when a scientist at the EPA admitted that he had been forced to go along with a determination that the safe MCL for fluoride was 4 ppm, when he knew that this level wasn’t safe. This professional and others at the EPA knew that the administrators were bowing to political pressure from politicians (e.g. Strom Thurmond) in certain states with areas of high natural fluoride and who were concerned that if a lower level was set for the MCL it would cost their states a lot of money to remove the fluoride.

As a result of this Dr Robert Carton and others set up a union at the EPA headquarters in an attempt to get a code of scientific integrity adopted at the EPA. This would forbid administrative staff from forcing scientists to make false statements about their scientific findings in order to fit into the “policy” of administrators. This same union after examining the scientific evidence came out in strong opposition to the so-called safety of the MCL and the MCLG for fluoride, both of which had been set at 4 ppm, and also the practice of water fluoridation.

Those who are interested can view Dr. Hirzy’s statement before a Senate subcommittee in the US Congress in 2000 ( ). Clearly, Bill’s opposition to fluoridation is science-based. Moreover, in a democracy like the US, like any other citizen, including Steve Slott, he is entitled to his opinion on a public policy issue like this, without being treated like some paid hack.

When Bill retired from his teaching position, Fluoride Action Network was only too happy to have such a qualified person work as our point person in Washington, DC. We have paid him a nominal salary to do this. That shouldn’t be used to suggest that he has somehow thrown science and his integrity out of the window, which I think Slott meant to imply when he says Bill is a “paid lobbyist for Connett’s antifluoridationist group, FAN.” Based on the science Bill is opposed to fluoridation. Based on the science FAN is opposed to fluoridation. It is a shame that Slott should think – or intimate – otherwise.

As far as lobbyists are concerned I think Steve would do better to wonder what the ADA is doing with 20 paid staff in DC, all of which are receiving a remuneration, which makes Bill’s nominal salary look like a pittance. One of the things that ADA is doing with its $100 million budget is to try to persuade Congress and state health departments not to allow dental therapists to perform basic dental procedures in low-income areas. Ironically, I believe that Steve is against the ADA’s position on this sensible and cost-effective measure. It has proved most successful in NZ.

In my view Bill Hirzy is an excellent educator on this and other issues. We believe that he can help with a lot of education in Washington, DC, not just with legislators but with the city council and with environmental and other public interest groups.  A lot of people in DC respect both his experience and his integrity.

Here is the link to Bill’s correction of the errors in his arsenic paper:

32) Finally, I attach Dr. Hirzy’s response to Ken’s comments on his input in part 3 of this thread:

In a paragraph headed in bold type Perrott cites my activism as reason to question my ability to properly assess risks. I freely admit making an error (soon to be rectified by publication of a corrigendum) in the annual cancer incidences for HFSA and pharmaceutical sodium fluoride. That said, nevertheless EPA did not find fault in my determination that HFSA causes about 100 times more cancer than pharmaceutical sodium fluoride. Neither does Perrott show any fault in that determination.

Perrott comments about my dismissal of NSF’s statement about their testing allegedly proving the amount of arsenic contributed by HFSA is non-detectable and perfectly safe, but he fails to address my observation that NSF in fact reports measurable amounts of arsenic contributed by treatment chemicals, and that those levels lead to 200 times higher cancer risk than USP NaF. In a debate one should address points raised by one’s opponent – if one can…..

After doing some calculations based on the New Zealand Specific Impurity Limit for arsenic, I do admit that the New Zealand standard is superior by a factor of 2.4 to that of NSF.  That is, however, faint praise in that it allows about 500 fold higher lung/bladder cancer incidence than pharmaceutical grade sodium fluoride. See below.

Regarding the arsenic levels in HFSA and Mr. Perrott’s being “suspicious” about my results and whether the HFSA samples I reported on were representative, Mr. Perrott cites the Brown et al. 2004 publication in the Journal of the American Water Works Association and kindly provided a link to the article. If he had read that article closely he would have noticed the support for my work on page 118. At page 118 of that piece, Brown et al. report testing 4 samples of HFSA, rejecting one because of excessive free HF, and finding arsenic levels of 9, 20 and 47 mg/kg, in the other three samples, all of which values fall within the range of the 33 samples I cited in my statistical analysis of arsenic levels in HFSA. Further on page 118, Brown et al. cite results from Weng et al. reporting on an unstated number of HFSA samples, finding an average of 28 mg/L and a maximum of 60 mg/L of arsenic – again within the range of my analysis. Finally, also on page 118 is citation of work by Casale, who found a range of 9.4 to 58.5 mg/L of arsenic – within the range of my analysis.

Concerning activism and suspicion, perhaps Perrott is correct in asserting that higher purity HFSA is available in New Zealand, but his activism in promoting  fluoridation could raise parallel suspicion about that.

Perrott dismisses as “a silly conspiracy theory” my recitation of data published by the U.S. Geological Survey (USGS) showing that 94% of the byproduct HFSA produced by phosphate manufacturers in 2011 was sold to water fluoridation systems, and coupled with solid data on sales prices, produced about $560,000,000 in revenues for those companies. If only 6% of HFSA found alternative markets, which USGS found to be valued by the producers at nearly double the value for the fluoridation market, where else would HFSA go than down our shower drains and toilets, etc. Pretty good business model for a “silly conspiracy” I’d say.

My citation of the violation in Wellington, Florida was the only one I knew about. How many more there may be/have been, who can tell? And why are HFSA producers not routinely supplying certificates of analysis for every batch sold rather than simply stating “Complies with NSF/ANSI Standard 60.”

What New Zealand Might Otherwise Do (Based in part on Standard for the Supply of Fluoride for Use in Water Treatment – Second Edition. New Zealand Water Supply and Disposal Association. 1997)

Assume density of 20% assay HFSA is 1.2 g/mL  (density of 24% assay is 1.24g/mL).

Pure HFSA is 79% w/w fluoride

1 mL of HFSA  x  1.2 g/mL  x  0.20  x .79 = 0.190 g F/mL HFSA = 190 mg F/mL HFSA

Assume need to add 0.50 mg F/L H2O

0.50 mg F/L H2O ÷ 190 mg F/mL HFSA = 2.6 x 10-3 mL HFSA/L H2O

2.6 x 10-3 mL HFSA/L H2O x 1.2 g HFSA/mL HFSA = 3.2 x 10-3 g HFSA = 3.2 x 10-6 kg HFSA/L H2O

SIL for As = 132 mg As/kg HFSA

1.32 x 102 mg As/kg HFSA  x  3.2 x 10-6 kg HFSA/L H2O  = 4.2 x 10-4 mg As/L = 0.42 ug As/L

Using the USEPA modified population Unit Risk value of 3.5 x 10-5/(ug As/L), a risk for lung/bladder cancer of 1.5 x 10-5 obtains. This is equivalent to 15 extra cancers per million population exposed for 70 years.

If 4 million people have been exposed at this level for 20 years, one would expect about 17 extra cancers to have developed.\

New Zealand’s SIL for arsenic is about 2.4 times more protective than the U.S. standard.

If pharmaceutical grade NaF had been used for this same period, delivering 0.00084 ug As/L, then New Zealand’s 4 million people exposed for 20 years may have developed about 0.03 such cancers.

If the New Zealand government were to have provided 4 million people with 2 L/day of water containing 0.50 mg added fluoride from pharmaceutical grade NaF for 20 years (and it is very likely that far fewer than 4 million would have opted to drink that water), it would have spend, in constant 2001 U.S. dollars, about $190,000.

If HFSA had been purchased at about half the price charged in the U.S., i.e $800/metric ton over that same period, and assuming New Zealanders use half as much water per capita as U.S. citizens, i.e. 50 U.S. gallons/day, and this practice ran for 20 years, then about $6,000,000 would have gone to phosphate producers.

And assuming it costs half as much in New Zealand to treat the cancers HFSA’s arsenic load produced, then an additional $30,000,000 would be spent on medical costs.\

So, if you are really determined to offer fluoridated drinking water to New Zealanders, you would be well advised to consider the substantial cost savings you would realize by providing free containers of water fluoridated with pharmaceutical grade NaF just to those who want it, while acceding to the demands of your citizens who most vehemently do not want fluoride in their drinking water.\

And, by the way, the New Zealand Lung and Bladder Cancer/Fluoridation Lottery could be cancelled too.  

Postscript. This will be my last contribution to this thread. I feel that I have presented my case fully in the book I co-authored (The Case Against Fluoride…). What I am more interested in now – having outlined some basic arguments against fluoridation in this thread (few of which have been satisfactorily rebutted) – is seeing what scientific case Ken can produce for fluoridation. This is meant to be the substance of the other thread and that is where I will now focus my efforts.

In this respect I have been disappointed in Ken’s ability – after four attempts to do so –including the last installment that he published yesterday (Dec 10) – to lay out a scientific case. So far Ken seems more adept at theorizing on why drinking fluoride should work rather than providing the studies that it actually does. In addition, he spends more time demonstrating his disdain for anyone opposed to fluoridation than actually producing the science which shows that fluoridation is “safe and effective” as proponents repeatedly claim. Finding fault with me or other opponents does not establish a case FOR fluoridation. It is a practice forced on millions of people that don’t want it. He defends this practice and as such it his obligation to present a scientific case FOR fluoridation and I am still hoping that he will do that.

Let me be more specific: what I had hoped to see by now is:

a) What primary scientific research Ken has read that gives him the confidence  that the epidemiological evidence is overwhelmingly in favor of fluoridation providing a significant benefit over and above the use of fluoridated toothpaste.

b) What his response is to the latest news from Scotland that a simple and cost-effective strategy has been devised that has been found to combat tooth decay in low-income children which does not involve forcing people to swallow fluoride who don’t want to.

c) A presentation of a weight of evidence analysis that would allow him and other promoters to dismiss all the concerns I have raised about fluoride’s impact on the brain and several other tissues.  We have presented this case in our book and again in both these threads. Our case is in black and white and documented, where is his response in black and white and documented?

In the process of doing this I would particularly would like to see him identify papers that have been conducted in NZ (or Australia for that matter), which have examined any of the health issues discussed in our book, or that have collected fluoride exposure levels in the urine, blood or bones of NZ citizens to gauge their exposure to fluoride both in the short-term or long-term. In other words I am anxious to find out:

a) the scientific basis for his confidence in the safety of water fluoridation;

b) the argument he would raise to support the notion – despite so many unknowns – that the practice does not violate the Precautionary Principle (see chapter 20 in our book and Tickner and Coffin, 2006), and

c) the basis for his confidence that there is an adequate margin of safety (see chapter 21 in our book) to protect everyone in a large population drinking fluoridated water – especially the most vulnerable – from any harmful effect.

I will continue to pursue his response to these challenges in the other thread: Ken’s Arguments For Fluoridation.


 Angmar-Månsson B, Whitford GM. (1982). Plasma fluoride levels and enamel fluorosis in the rat. Caries Res. 1982;16(4):334-9.

CDC (1999). Centers for Disease Control and Prevention, “Achievements in Public Health, 1900–1999: Fluoridation of Drinking Water to Prevent Dental Caries,” Mortality and Morbidity Weekly Review 48, no. 41 (October 22, 1999): 933–40,

CDC (2010). Beltrán-Aguilar, D et al., Prevalence and Severity of Dental Fluorosis in the United States, 1999-2004. MMWR, 53; November.

Colquhoun J. and R. Mann (1986). “The Hastings Fluoridation Experiment: Science or Swindle?” The Ecologist 16, no. 6: 243–48.

Colquhoun, J (1987). Education and Fluoridation in New Zealand: An Historical Study,” Ph.D. diss., University of Auckland, New Zealand.

Colquhoun J. and B. Wilson (1999). “The Lost Control and Other Mysteries: Further Revelations on New Zealand’s Fluoridation Trial,” Accountability in Research 6, no. 4:373–94.

Connett, P., Beck, J and Micklem HS. The Case Against Fluoride. Chelsea Green, White River Junction, Vermont, 2010.

Dunipace AJ, et al. (1995). Effect of aging on animal response to chronic fluoride exposure. Journal of Dental Research 74(1):358-68.

Heller KE, et al. (1997).“Dental Caries and Dental Fluorosis at

Varying Water Fluoride Concentrations,” Journal of Public Health Dentistry 57, no. 3: 136–43.

Hirzy (2000). Video.

NRC (2006). Fluoride in Drinking Water: A Scientific Review of EPA’s Standards (2006)

Sawan RM, et al. (2010). Fluoride increases lead concentrations in whole blood and in calcified tissues from lead-exposed rats. Toxicology 271(1-2):21-6.

Schlesinger ER, et al. (1956) “Newburgh-Kingston Caries-Fluorine Study XIII. Pediatric Findings After Ten Years,” Journal of the American Dental Association 52, no. 3: 296–306.

Slade, G.D., A.J. Spencer, et al. (1996). “Caries experience among children in fluoridated Townsville and unfluoridated Brisbane.” Aust N Z J Public Health 20(6): 623-9.

Tickner, J and M. Coffin (2006). “What Does the Precautionary Principle Mean for Evidence-Based Dentistry?” Journal of Evidence Based Dental Practice 6, no. 1: 6–15.

Varner et al. (1998).“Chronic Administration of Aluminum-Fluoride or Sodium-Fluoride to Rats in Drinking Water: Alterations in

Neuronal and Cerebrovascular Integrity,” Brain Research 784, no. 1–2: 284–98.

Xiang, Q et al. (2003a) “Effect of Fluoride in Drinking Water on Children’s Intelligence,” Fluoride 36, no. 2 (2003): 84–94,

Xiang, Q et al.(2003b), “Blood Lead of Children in Wamiao-Xinhuai Intelligence Study” (letter), Fluoride 36, no. 3 (2003):198–99,

Anyone wanting to follow the debate and/or check back over previous articles in the debate can find the list of articles at Fluoride Debate.

See also:

Similar articles on fluoridation
Making sense of fluoride Facebook page

Census 2013 – religious diversity Ken Perrott Dec 10


Statistics New Zealand has released preliminary figures for religious affiliation from the 2013 census.

The raw figures show for the major affiliations (Christian and No religion) the following:

Religious affiliation Number
No religion 1,635,348
Christian 1,879,671
Total Responses  4,343,781
Total People  4,242,048
Double Dipping?*  101,733

It is interesting to compare the last census figures with those for the previous four.


As we can see, the godless trend has continued unabated.

One thing for sure – Christians can no longer claim to make up the majority of the country’s population.

*Double Dipping arises from people putting down more than one answer to the question. Eg – “Born again” and “Assembly of God.” It most probably occurs for the Christian, rather than No religious group. If this is the case we should adjust the Christian total to 1,879,671 -  101,733 = 1,777,938.

This would cut Christians as a proportion of the total population to 41.9%.

The No religion is accordingly 37.7%.

The other major religions have Hindu – 2.1%, Buddhist – 1.4% and Islam – 1.1%.

For more detail see 2013 Census where  tables of data can be downloaded.

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