The Anti-Fluoride Brigade – what if they are right?

By Michael Edmonds 10/06/2013 64


Sometimes when I come across an argument that goes against the current scientific consensus, I have to stop and ask myself – what if they are right? After all science doesn’t always get things right (indeed as science is a self correcting process we know that occasionally they way we look at the world has to be adjusted to match new evidence).

Often this means I end up looking at the arguments put forward by those arguing against the scientific consensus – AIDS denialists,  anti-vaxxers, moon landing hoaxers, climate change dissenters, the list goes on. And now most recently those opposing fluoridation.

It always seems like the fair thing to do. But time and time again, I find myself wading through dubious arguments, ad hominem attacks, emotive misdirection and anti-science sentiments.

So yet again, I have found myself reading random anecdotes, misrepresented studies, emotive references to pesticides, etc, which have only convinced me that fluoridation is safe and beneficial. Some arguments against fluoridation may be presented on professional looking websites such as FANNZ, but when it comes down to it science relies on substance not appearance.

Mind you, I have at least gained a better understanding of those who see it as a values rather than a scientific argument (i.e. is “mass medication” ethical?) which I think is a more valid debate.

I wonder if those who promote anti-fluoridation arguments ever stop to look at the other side of the argument? To actually try and understand the science in depth rather than pick and choose arguments which they THINK make their case?


64 Responses to “The Anti-Fluoride Brigade – what if they are right?”

  • I don’t think Ive ever come across a topic as polarised as this. I must admit when I heard Sir Peter Gluckman state on radio NZ yestersday when asked if the science was “closed” I was a little curious when he said yes. Science does not even close totally.
    The part I find hard to understand, and I did watch the opening and closing arguments on the Hamilton City Council Tribunal, is why Principal dental officers for Canada, Brisbane and Auckland NZ have , once retired, have come out with concerns about Fluoridation of water. It appears the argument is divided in three facets. The accumulation of F in animals, the efficacy of topical vs ingestion and the effect on G proteins. I note that Mr Bad science himself Dr Ben Goldacre notes “The reality is that anybody making any confident statement about fluoride – positive or negative – is speaking way beyond the evidence.” http://www.badscience.net/2008/02/foreign-substances-in-your-precious-bodily-fluids/ Still very curious about this.

    • Thanks for the link. it makes for interesting reading. Not sure if it is reasonable for Ben to include mention of high fluoride levels being potentially linked to cancer, when the levels in the study he mentioned were much higher than that used for intentional fluoridation around the world.
      It would be interesting to know how much the objection of the principal dental officers you mention relies on their interpretation of the science or on their value judgements (both of which are valid considerations in this argument).

  • Gosh James, reading Sir Peter saying the science was “closed” is a bit of a shock. Just as a clinician providing a drug to an individual may be surprised at the results, so too a public health intervetion may throw up surprise results in some cohorts.

  • @ Michael, found these
    Dr Hardy Limeback was the Canadian,
    http://www.youtube.com/watch?v=1sRWgDff8zY
    (1hr presentation)

    John Colloqhoun ?(spelling) was the NZ PDO(Auckland),
    http://www.youtube.com/watch?v=e8th-Bbb0LQ
    (1hr)

    Dr. Andrew Harms, was the President of the South Australian Dental Association, (not the PDO.)
    -Harms actually provided a submission to the Hamilton tribunal and is most definitely self confessed “anti-fluoride”) I can’t find anything about him that isn’t on an anti-F website.

    Another commonly referred to ( by the anti-camp) is Dr Phyllis Mullinex, study from Pharmacology/Toxicology
    http://www.youtube.com/watch?v=Hci7BnWydAo

    The links are to their own talks, rather than anti fluoride groups making summations of them.
    It is obvious there are a number of conspiracy theorist types pushing the fluoride is evil bandwagon and a plethora of websites that certainly make their case hard to review but I’m reasonably sure the above are not part of that, and whilst I observed many at the Hamilton tribunal were “sensitive individuals” there were submissions from Dr Peter Scanlan, Dr Jane Beck and Dr Anna Goodwin, who gave fairly solid presentations on potential harms.
    Either way will be interested to see how this develops.

  • I’m somewhat concerned that Sir Peter should regard the science as ‘closed’ – it sends the wrong message around certainty & science. (I’ve just spent the morning talking about science/pseudoscience with a bunch of year 10 students, explaining that science will never say we have 100% certainty around an issue, while those espousing pseudoscience often give that message.)

  • “Closed” is indeed quite strong, but it is likely an abbreviation of “the science is good enough at present to make a sensible policy decision, so lets tick that box and move on to other parts of the problem where we’re less sure”. [Daniel]

  • Perhaps someone should raise this with Peter – or maybe he will see the comments here. People like him should just not be saying things like that – they should be working to give a more realistic picture ipof how science works. Unfortuantely the opponents of science pick such things up, even invent them in the case of global warming, to discredit science. One of our own should not help them out.

    Mind you – we should do this in a way that concedes to some of the anti-science propaganda antifluoridationist and others come out with. There are some huge porkies being told by these people – for example use data from high fluoride treatments to attack fluoridation – and we need to expose that. But we should not do that dogmatically.

  • For anyone wanting to read a good summary of the research I recommend Dr Paul Connett’s book ‘The Case Against Fluoride’. This is available in Hastings libraries and from the internet. Dr Connett, a toxicologist, presented the findings of his book to the Ministry of Health two years ago and asked them to critique his work. They have not done so and refuse to debate him. At the very least supporters of fluoridation should publish research that shows fluoride to be absolutely safe for all ages and for people with multi sensitivities. If they can’t show us this research then it should not be put into the water.
    Despite fluoridation in Hastings for 60 years our elderly people are not blood tested for fluoride toxicity. Fluoride is known to accumulate in the body. Blood testing people with arthritis, thyroid, insomnia, skin and gastric conditions to measure fluoride levels would signal if fluoride toxicity is a concern. The test is available through Canterbury Laboratories and costs $100 if accessed privately.

    • Angela, two points

      Nothing is “absolutely safe”. If any one tells you that something is absolutely safe then they are not basing their statement on science. Cars for example, are relatively safe, but under some circumstances they can be lethal. Thus we take a calculated risk whenever we drive one. It is the same with most things we consume, including fluoridated water.
      As far as I can see there is no reliable evidence to show that fluoride is harmful, and certainly nothing to connect it to all the diseases you list. Though this is a fairly common tactic used by those opposing something – to blame it for every disease around.
      I’m sure anyone wanting to test their fluoride levels could have their doctor do so.
      Give that large areas on NZ have not been fluoridated while others are,if fluoride was causing disease, then I would have thought there would be obvious increases in diseases in the fluoridated areas. I’m not aware of any such data, are you?

  • The problem with a F blood test is setting values for normal and excessive etc. we all ingest F whether in a fluoridated region or not – in a sense we should consider it almost as an essential element because it is incorporated into bioapatites and influence their strength. Too little or too much is apparently bad.

    If a test showed no F in my blood I would worry – but I don’t know what excessive levels would be.

    Another problem with all this talk of harmful effects – it is easy to find a study showing a harmful effect at high concentrations. But the relevant concentration is not high – it’s 0.7 – 1.0 ppm.

  • Just to clarify, fluoride ion concentration in blood can, not surprisingly, vary greatly – but reported concentrations are typically around 0.02 ppm. I should note that the water treatment chemical HFA completely and rapidly dissociates when dissolved in potable water producing fluoride and silica ( already present in potable water ), so no worries about HFA concentrations in blood.

    I’m not sure whether blood fluoride concentration is routinely available via your doctor, as usual method appears to use ion-selective electrode, so many clinical labs may not analyse, and forward samples to a few labs with suitable electrodes. However, any numbers without context would be meaningless.

    Anyone wondering about whether science will triumph should visit the National Fluoridation Information Service site.
    http://www.rph.org.nz/content/14350004-1cf6-45ad-a32d-d35311bfe2fc.html

    If you review the activities in Environment Scan
    http://www.rph.org.nz/content/79db9a2a-a6f6-431f-8657-c85bc439b973.cmr
    you will realise that they are fighting an uphill battle. They are supposed to provide technical support to the frontline soldiers in District Health Boards and public health units on request.

    It’s obvious that some council officials regard potable water fluoridation as something imposed on them that requires valuable time and resources. That may also apply to some heath officials, eg one who apparently tried to present to a council discussion in Lower Hutt by Skype. “Council staff advised that the use of Skype technology was disruptive and added confusion to the discussion.” Wow, how surprising is that?. The cost of getting a suitable person out into the wop-wops like Lower Hutt must be huge.

    From the Discussion and Conclusions of the report…
    “While the balance of evidence from the most up to date science supports continued benefits and safety from community water fluoridation, it continues to be debated by parts of the community. Coordinated multiple submissions of the same document by
    Fluoride Action Network New Zealand and others opposed to CWF have served to overwhelm councillors, in several cases in 2011.

    Fluoridegate Legal Action NZ, a subsidiary of FANNZ, wrote to all councils in New Zealand late 2011 stating they were issuing a formal notice of legal action if the councils continued CWF. While the Ministry of Health found the letter had no legal standing, the threat of legal action for collective and individual liability may have
    served to intimidate many councillors. ”

    So after such a well-written and detailed report of NFIS’s attempts to educate health officials and councils, their annual plan for 2012-2013 ( which is replete with diagrams of multiple linkages and other corporate jargon ) is very similar to the previous year.

    Somebody should inform them that repeating the same actions and expecting different outcomes results in madness. They need to tell their stakeholders that they need articulate reinforcements and more enthusiasm from their front line troops in public health.

  • As it happens, I’m just reading a review of fluorosis in livestock so I can shed some light on this discussion:
    C. Livesey and J. Payne (2011) Diagnosis and investigation of fluorosis in livestock and horses.
    http://inpractice.bmj.com/content/33/9/454.abstract

    Plasma levels of F
    Normal 0.5 mg/L

    Urine levels
    Normal urine 1-5 mgF/kg wet weight
    Borderline urine 20-30 mgF/kg wet weight
    Systemic toxicity >35 mgF/kg wet weight

    I’m sure it wouldn’t take too much digging to find the equivalent ranges for humans.

    The authors note that dental fluorosis is the earliest visible sign of chronic fluorosis in mammals; there is a standard assessment index used for livestock. Deans Index is an equivalent index used to assess human dental fluorosis, in parts of the world with naturally high F.

    It seems dubious to me that the demands for additional scientific information (which would have to be paid for by all of us) would change those minds which appear to be firmly made up. Just look at the ERMA reassessment process for 1080 – major review of evidence – doesn’t seem to have had an enlightening effect on the anti-1080 crowd.

  • Try again using words instead of symbols

    Plasma F
    Normal range less than 0.5 mg per L
    Mild fluorosis 0.2 to 0.5 mg per L
    Severe chronic fluorosis greater than 0.5 mg per L

  • Carol,

    Quite a difference to my source for fluoride, could they possibly be total fluorine?

    ” Mean plasma levels in individuals living in areas with a water fluoride concentration of 0.1 mg/L or less are normally 9.5 μg /L, compared to a mean plasma fluoride level of 19-28.5 μg/L in individuals living in areas with a water fluoride content of 1.0 mg/L.”

    http://ec.europa.eu/health/scientific_committees/opinions_layman/fluoridation/en/l-3/2.htm

  • Bruce, the levels I gave were for livestock (ruminants).
    By all means check out that review; I can email it to you if you can’t get it online.
    The data are for fluoride, not total F.
    Note the difference in units between mg/L and ug/L.

  • Bruce: I’m just thinking out loud here: the data you cited showed a 2-3 fold difference in plasma F in response to a 10fold difference in water concentrations.
    These data probabaly all lie in the normal range that I gave for dental fluorosis occurrence..?
    Also, the species differences are probably important.

  • Carol,

    I’ve now read a few more abstracts and it seems the fluoride concentration in blood ( eg ~0.020 mg/L ) is measured and expressed as the free fluoride ion, as determined by ion selective electrode.

    That value ( ~0.020 mg/L ) seems to be the typical fluoride concentration used in most studies, which also appear to use the free fluoride ion concentration in blood as their unit.

    As I understand the process ( but I could be very wrong ), the free fluoride concentration in drinking water ( eg 0.7 – 1.0 mg/L ) converts to HF in the acidic human digestive system and that HF passes through the lining into the body, where it is again converted to the free fluoride ion at blood pH.

    I’m not sure where the < 0.5 mg/L comes from, but I'm assuming it includes other fluoride salts, which may have minimal relevance.

  • If people looked at what I said rather than misquote me, you will note I said/wrote “effectively settled” for the very reason that science is never closed. (see http://www.pmcsa.org.nz)
    But the key issue is that the real debate here is not about science but other issues and science is being misused as a proxy for a different debate.

    • Thanks Sir Peter, “effectively settled” certainly is not the same as saying the science is “closed”.
      The point about the core of the debate being about values rather than the science, as you have discussed on your website is an important one, that I think many science advocates are starting to take on board.

  • Hi Bruce,
    I owe you an apology. I mis-read the plasma F data from the review of fluorosis in livestock that I quoted. The correct data is:

    Normal less than 0.1 mg/L fluoride
    Mild fluorosis 0.2 to 0.5 mg/L
    Severe chronic fluorosis >0.5 mg/L

    This is for livestock rather than humans, but it looks more sensible in relation to the plasma levels you referred to (which all appear to be below the threshold for the onset of mild fluorosis).

  • Hi Carol,

    Thanks for the clarification, no apology required, it’s just nice to sort out the discrepancy.

    Please keep having fun.

  • With respect, Peter, you also said, “With regard to fluoride, there have been genuine concerns raised regarding risks of bone disease, thyroid disease, brain disease and cancer. While these issues have been settled, they continue to be emphasized by those who oppose fluoride.”

    Are these issues really settled? With what degree of certainty?

  • Peter, in your blog & press release you said, “effectively settled.’ On the radio you said, “reasonably settled.”
    http://podcast.radionz.co.nz/mnr/mnr-20130613-0640-chief_scientist_says_fluoride_row_not_scientific_but_political-048.mp3

    You have been widely reported in the media as having said the evidence is settled.

    Your comments re the real issue is not one of science but one of values is spot on.

    Your comment that your opinion on that is no more or less valid than anyone else’s is also valid.

    Your comment that scientists are not qualified to make values judgements on behalf of science are also spot on. Former Director General of Health George Salmon is on record saying the same thing.
    You have been widely reported as having said that the science is settled. That’s the message the public are hearing. eg http://www.stuff.co.nz/national/health/8792892/Hamilton-may-go-to-referendum-on-fluoride

    You owe society and science and the values debate a public statement to clarify that the science is NOT settled and that scientists are not qualified any more than any one else to express an opinion in a values debate.

    • RonL,
      The debate over fluoridation has been confounded by a blurring of scientific and values arguments. Scientists can contribute by clarifying the science which I think is what Sir Peter is trying to do.
      With regards to values statements anyone can contribute an opinion, though one might expect arguments which are consistent in their logic and which are based on facts to hold more sway.

  • Gluckman’s role is to be a guiding light… to be the government’s key communicator… he made two important messages… the most important was that it was a values debate in which scientists had no more/less right to an opinion than anyone else. Unfortunately this was smothered by reports of settled science.

    Gluckman needs to correct the media reports… even Peter Griggin has falsely reported what Gluckman said.

    If the false reporting isn’t corrected, the Gluckman’s reputation suffers… he becomes guilty/biased by an act of omission.

    • RonL,
      I disagree. Professor Gluckman made two important, valid and separate points. You seem to be still confounding them together. Stating that the science is effectively settled does not override the values debate.

      Could you explain exactly what you mean by “Peter Griffin (I guessing you got the name wrong???) has falsely reported what Gluckman said”?

  • No, I got an email from the SMC (Peter Griffin) with the false headline, “Fluoride Science Settled.”

    I heard Gluckman on the radio say the science was “reasonably” settled. In his release he said “essentially” settled. What was reported by the media, SMC and members of the Objective Skeptic Society in various so-called sciblogs was that he said the science was settled.

    Gluckman came onto sciblogs to deny he said the science was settled… he should also make such a public statement… otherwise be implicitly endorses what the public are being told.

  • RonL,

    So are you concerned that “reasonably settled”, “essentially settled” and “settled” do not mean the same thing?

    Never heard of the Objective Skeptics Society before.

    And in this very blog, Professor Gluckman confirmed he had said/wrote “effectively settled”, a term I think is quite reasonable as it suggests correctly that there is substantial evidence that fluoridation is both safe and effective, however, it does not eliminate the possibility that should contradictory evidence arise, that the view will change (i.e. the “essentially” part of the quote).

  • RonL. Lesson form Feynman

    ““If you thought that science was certain – well, that is just an error on your part.”
    ― Richard P. Feynman

  • Ross, I’ve never said the science was certain… that’s my point… it’s not.

    Michael, to say that the science is settled is to say that it finite. Gluckman has been widely reported as saying the science is settled. That’s what the public have heard… reinforced by people who should have known better such as scibloggers… even Peter Griffin’s SMC put a press release out saying Gluckman had said it was settled.

    Gluckman has corrected the myth here… but not publicly… why not???

    On Radio New Zealand he said it was ‘reasonably’ settled.

    It’s not settled… it’s certainly overhyped, as noted as early as the 2000 york report.

    And Yes, I am concerned that so-called scibloggers, such as yourself, are trying to redefine the English language by suggesting that “reasonably settled”, “essentially settled” and “settled” mean the same thing.

  • RonL,
    Professor Gluckman has stated here that the science is “effectively settled”. You state that he has said elsewhere that it is “reasonably settled.” I do not think those two comments are particularly different.
    With regards to it have been reported that he has stated that the science is “settled” perhaps that is an oversimplification, but as you state that was a “headline”. Headlines do tend to simplify issues only to spell out the qualifiers in the actual story.
    Science communication requires a balance between make the science clear and understandable without oversimplifying it too much. I think Professor Gluckman has found a good balance in his comments on fluoridation.

  • RE: “Ross, I’ve never said the science was certain… that’s my point… it’s not.”

    Just noticed Ross’s post used the word certain, not settled. To remove doubt…

    Certain as adjective
    Known for sure; established beyond doubt.

    Settled as adjective
    Established or decided beyond dispute or doubt.

    So Gluckman said it was essentially settled and reasonably settled… ie, there is some doubt, ie it is not settled…

  • RonL,
    The way I am reading “essentially settled” and “reasonably settled” is that the bulk of the evidence supports fluoridation, but there is always the possibility that future evidence will require this position to be reassessed.
    Seems a reasonable position for a scientist.

  • Michael, I gave a reference.. obviously you didn’t ;isten to his own voice.
    http://podcast.radionz.co.nz/mnr/mnr-20130613-0640-chief_scientist_says_fluoride_row_not_scientific_but_political-048.mp3

    Gluckman’s most profound statements related to the fact that scientists aren’t the one’s who should be making the decision… he says it’s a values decision… ie, one for ordinary people to make. He says that scientists are not qualified to make such decisions… no more than anyone else.

    Your attempts to water down your mistakes doesn’t look good for a so-called objective sci-blogger.

    The first up comment heard him repeat the settled sentiment… “I must admit when I heard Sir Peter Gluckman state on radio NZ yestersday when asked if the science was “closed” I was a little curious when he said yes.”

    On this I agree with Dr Ben Goldacre as noted in the first comment…. Goldacre notes “The reality is that anybody making any confident statement about fluoride – positive or negative – is speaking way beyond the evidence.” http://www.badscience.net/2008/02/foreign-substances-in-your-precious-bodily-fluids/

  • RonL,

    You are confounding Professor Gluckman’s two points again.
    That the decision to fluoridate involves significant value issues is quite clear. But science can still provide us with information about the effectiveness and safety of fluoridation.
    If people want to argue about fluoridation based on values (e.g. discussions of mass medication etc) then I think that is a much more valuable discussion than having people oppose it because they have been emotively swayed by the fact that fluoridating agents are byproducts of industry.
    And while Ben Goldacre has a solid background in assessing medicine related issues that does not mean he is right all of the time. I’m wary of any arguments from authority.

  • Goldacre says, “The reality is that anybody making any confident statement about fluoride – positive or negative – is speaking way beyond the evidence. In 1999 the Department of Health commissioned the Centre for Reviews and Dissemination at York University to do a systematic review of the evidence on the benefits of fluoridation on dental health and to look for evidence of harm. Little new work has been done since.

    They found 3200 research papers, mostly of very poor quality (full references on badscience.net as ever). The ones which met the minimum quality threshold suggested that there was vaguely, possibly, around a 15% increase in the number of children without dental caries in areas with fluoridated water, but the studies generally couldn’t exclude other explanations for the variance. Of course, the big idea with fluoride in water is that it can reduce social inequalities in dental health, because everyone drinks it: but there isn’t much evidence on that either, the work is even poorer quality, and the results are inconsistent.

    So when the British Dental Association says there is “overwhelming evidence” that adding fluoride to water helps fight against tooth decay, they’re with General Ripper. And when Alan Johnson says: “Fluoridation is an effective and relatively easy way to help address health inequalities, giving children from poorer backgrounds a dental health boost that can last a lifetime,” he’s really just pushing an admirably old fashioned line that complex social problems can be addressed with £50m worth of atoms. The people behind the York review have had to spend a fair amount of time pointing out that people are misrepresenting their work.”

    On this Goldacre is spot on. The science is not settled at all… it is generally of very poor quality. To say otherwise to to side with junk science.

    For Gluckman to even say that the Fluoridation science was essentially or reasonably settled defies the scientific process. It belittles his position as chief scientist… unless he’s a puppet of some higher force.

  • Michael, it is really sad to see good people such as yourself get blinded by ideology.

    This is one argument that can’t be won on science simply because the science is so tenuous and unsettled.

    Gluckman said it was like adding iodine to salt… that’s absolute rubbish and he knows it. Iodine is an essential element… lack of iodine causes brain damage.

    Salt is not a utility; water is.

    People buy salt off the shelf… they choose to buy iodised or non-iodised… they have a choice. Besides, when salt was first iodised an error was made and te amount added was considerably more than needed. Farmers for decades used iodophors to sterilise milking machines meaning there was more than enough iodine in milk… that changed when iodophors were gradually replaced.

    Mass medicating water with fluoride is not the same as adding iodine to table salt.

  • RonL,
    To state that it “is really sad to see good people such as yourself get blinded by ideology” shows you are not understanding what I have written.
    My interpretation of the science papers and reviews I have read tells me that the science supports fluoridation – if this is in disagreement with you and Ben Goldacre then so be it.
    Suggesting that Ben Goldacre has it completely right (and cutting and pasting large chunks from his blog) is an argument from authority.

    With regards to the analogy of it is like adding iodine to salt, it is similar in that you are adding something beneficial to a substance consumed by the majority of people. However, like most analogies it falls down it you try and align the analogy too closely e.g. salt is indeed not a ultility.

    And as you have pointed out before, and I have agreed with you (nice to find points of agreement) the concept of mass medication is a values issues and can (and should) be debated separately from the science.

  • Ron, you do actually have a choice when it comes to drinking water. No-one is forcing you to drink tap water. You are entirely free to buy your own drinking water at the supermarket, or fill up your bottle at the Petone aquifer, or whatever you like. I think the choice argument is rather a weak one.

  • Carol, you are correct… and put filters in, etc, etc. I suspect a lot of people no longer drink tap water by choice… at what cost?

    Tap water costs $1.50 per m3. A whole industry has built up around ‘purified water’ which costs approximately $1,500 per m3. But no one has built that into any cost benefit analysis that I’ve seen.

    There is no significant difference in cost between iodised and non-iodised salt… one has to by one or the other. One doesn’t have to spend a truck load of money to avoid the other.

    So if one didn’t want to drink fluoridated water added to tap water then one has to spend thousands of dollars over time to avoid it.

    As I said, there’s a whole industry been built up around giving people that choice.

    What choice is that???

  • The science is settled… sure is… regardless of whether fluoride is added to water supplies or not dental health has improved over the past 30-40 years… ie, fluoride in water has made no obvious difference.

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2001050/figure/fig1/

    From hear.

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2001050/pdf/bmj-335-7622-ac-00699.pdf

    Sir Iain Chalmers is a British health services researcher, one of the founders of the Cochrane Collaboration,

    http://en.wikipedia.org/wiki/Iain_Chalmers

    • RonL,
      Nice graph, but it doesn’t appear to take into account that some water supplies might naturally contain fluoride, nor does it identify what other approaches are taken in different countries to reduce tooth decay. And given an improved understanding of dental hygiene across time one would expect that number of decayed teeth would decrease across time, the key point is how does it differ between populations with fluoridated water supplies and those with non-fluoridated water supplies (and which contain no significant natural fluoride).

      The second report you link to does suggest
      “Estimates of the increase in the proportion of children without caries in fluoridated areas versus nonfluoridated
      areas varied (median 15%, interquartile range 5% to 22%).”
      though they do point out there may be bias due to poor adjustment for confounders.

      With Hamilton and other towns around NZ stopping fluoridation we should have some useful data for this coming out of NZ towns and cities over the next decade or so.

      Carol, Bruce
      This is where we are moving into the values decisions that Professor Gluckman spoke about. Assuming that fluoride is safe and effective, one does have to ask whether the benefits of fluoridation override the cost of doing it, as well as taking away people’s choice around what goes into their water.
      Public good versus personal freedom, always a contentious issue as most of us draw the line at slightly (or sometimes substantially) different points.

  • Ron,

    A local company is selling fluoride removal systems for less than $500, and replacement cartridges ( 2500 liters ) around $100.

    They suggest annual replacement is typical, so you should get a decade of water for drinking, cooking, and teeth cleaning for your thousands of dollars. If you’re frugal, you could get a couple of decades or more.

  • Ron: anyone can collect and drink rainwater if they are so inclined. Ten percent of NZ households do. Of course, there is a not-insignifiant risk of a microbial burden, but hey! it’s low-fluoride and from all the fuss going on, you would think that was the single most important thing about drinking water.

    I do think the ‘prohibitive cost of alternatives’ argument is a weak one.

  • The government wants an innovation culture, so let them cough up some bikkies to :-

    1. Develop cheap and simple domestic dosing systems for fluoride addition to water.
    2. Develop cheap and simple domestic fluoride removal systems for treated community water systems.

    If there really is a national and global market for domestic fluoride addition/removal systems, bulk demand would build industries and lower unit and consumable prices. Then homeowners could decide what they want.

    I suspect some concerned citizens find lobbying the local councils cheaper and more fun.

    From what I can see, many of the domestic “water purification” systems currently available focus on removal of particulates, salts ( excluding fluoride) and especially taints/odour from organics in the water. That suggests fluoride isn’t yet a major issue for purchasers.

  • I definitely do the same thing. I can’t go warning people against to wiles of Cognitive Bias if I don’t put myself to the test as well.

    And just like you, I’m left disappointed. Just the other day I was on the fence (so to speak) and really wanted to be convinced by an anti-fluorider, but sadly was met with a rather nasty ad hominem attack telling me that unless I could detail economical and communist agendas, I wasn’t worth talking to. I know right, what the hell kind of rebuttal is that?

    On the up side, the person who said that to me rather quickly revealed that they don’t have any sort of credibility or constructive rebuttal of proof for their argument. And now I’m firmly back on the pro side of the fence. I’ve met with far too many who can only resort to ad hominem or pull out the weak “why should it be pushed on me” argument.

  • Bruce, can you provide a link to the fluoride removal systems for less than $500, and replacement cartridges ( 2500 liters ) around $100?

    You haven’t factored in the cost of plumbing it in etc. One of the problems with filters is they can remove beneficial elements such as calcium from water.

    Carol, retrofitting water tanks and associated pumps and plumbing costs several thousand dollars. It costs clients about $5000 to install split plumbing systems for using rainwater when mandated by Council. The MOH advises against collecting roof water for drinking for other health reasons. I was brought up on a farm… I recall cleaning the water tank out and removing possum and bird skeletons… nice…!

  • Interesting, in an email from the SMC they are insisting Gluckman said the science was closed. Obviously they don’t follow their own sciblogs…

    SMC: “Beyond semantics of the word “effectively”, it would be hard for him to claim that he didn’t say the science was settled as this post came directly from his office.”

    lol.

  • Thanks Bruce… Activated Alumina and charcoal filters

    Surprised people opposed to fluoride would use an aluminium oxide filter…

    Would cost about $800 to purchase and install professionally. so first year costs would be about $1000 with ongoing about $200. The speed of delivery wouldn’t be very convenient for filling a jug.

    So, let’s say 1% of people in hamilton wanted to do that… at 3 people per household, say, that’s about 500 households, or $500,000 for the first year and $100,000 thereafter.

    At $5 for 10 litres I suspect most people would simply buy purified water at the supermarket.

    I wonder… let’s say just 1% of people do that. Let’s say they drink 1 litre a day. For Hamilton that would equate to 14,600 people, or $7,300 per day, that’s about $2.6 million per year.

    I wonder if these figures should be built into any cost benefit analysis? I suspect it would marginalise any economic benefits, so no doubt they won’t. It’s part of the bias of political science… leave out factors that don’t prop up the desired outcome.

  • Curiously enough, Ron, your maths appears to support your biases. Unless Hamilton has had a dramatic overnight surge in population, one percent of its population is 1460 people.

  • Hi Ron, yes I had missed Sir Peter’s comment here, and can see his point when he says he “wrote “effectively settled” for the very reason that science is never closed.”

  • Ron,

    Not certain why you want to factor in ~$400 of installation costs for something that people already install by connecting to an available tap.

    Let’s assume the installation cost is $100, benchtop unit is $450, both cartridges ( but wait, there’s more, it removes odours as well ! ) $155 for 2500 litres, a unit lifetime 10 years, 1 litre consumption/day, with annual replacement of Actival cartridge, and 2 years for Carbon cartridge, as suggested on the WWW site.

    I could be wrong, but that works out at 9c/litre, or $33/year/person. If 1% of Hamilton’s citizens want 1 litre/day and their own system, that’s 1500 x $33 = ~$50,000/year, even less if they share the system.

    By the way, my last Millipore Cartridge water purification system, was apparently installed in 1979, and is still going, so 10 years is realistic.

    I’m sure I could choose parameters to make it look uneconomic, but the above seems OK to me, although 1L/day might be low..

  • Having just done a do-up and recently built a house, $100 for installation is way low… regardless, these costs need to be included in CBAs…

  • Well even if I used your $400, my calculation would would be around 10c/liter, somewhat lower than your 50c/liter.

    I would expect that if 1500 people in one city wanted one, the costs of both unit and consumables would be significantly lower than these retail prices.

    I suspect that CBA would be a waste of time, as the benefits aren’t even acknowledged by opponents of fluoridation.

  • The real question (I think) is what kind of a country puts the appearance of their teeth over the function of their bones and brain? Answer: America.

    • Perhaps you could clarify what fluoridation has to do with the function of bones or the brain? There is no evidence that I am aware of that shows fluoride at the levels in fluoridated water has any significant effect on bones or the brain.
      Perhaps you know differently? If so could you please provide your evidence to support your position?

  • For the record, in several interviews Gluckman did say, “the science is settled.”

    eg, on Radio Live

    http://www.radiolive.co.nz/Professor-Sir-Peter-Gluckman-on-Fluoride/tabid/506/articleID/35962/Default.aspx

    Gluckman should front up with this ‘settled’ science. I note that even the union representing EPA scientists in the USA oppose fluoridation based on what its own scientists have found/experienced.

    http://www.nteu280.org/Issues/Fluoride/NTEU280-Fluoride.htm

    This is a really interesting topic. One I haven’t looked at before, but anyone who dogmatically claims the ‘science is settled’ is certainly not in touch with the science… even if that person is a Knight. The science is clearly not settled.

  • Gluckman should front up with this ‘settled’ science. I note that even the union representing EPA scientists in the USA oppose fluoridation based on what its own scientists have found/experienced.

    http://www.nteu280.org/Issues/Fluoride/NTEU280-Fluoride.htm

    This is a really interesting topic. One I haven’t looked at before, but anyone who dogmatically claims the ‘science is settled’ is certainly not in touch with the science… even if that person is a Knight. The science is clearly not settled.

  • Michael, there is evidence that fluoride at the levels recommended for oral health also has a positive effect on bones. One very good study I have read shows that bone fractures increase at lower and higher levels of F.

    As for the brain antifluoridationists are currently spreading the myth that F causes calcification in the pineal gland. Simple reflection shows that calcification results from reactions of Ca with phosphate and organic materials. The calcium compounds and bioapatites formed during calcification provide sites for F absorption (F incorporation into the structures). So increases in F concentration in the pineal gland are a natural result of, not a cause for, calcification.

    It’s another case where the science is being misrepresented.