Tag Archives: Hamilton

Non-fluoridated Christchurch does not have better teeth than fluoridated Auckland


It seems every time anti-fluoride propagandists present data it is either cherry-picked, distorted or misleading. Often all three. So it is hardly a surprise to find local anti-fluoride propagandists are telling porkies again.

They have been promoting the above graphic claiming it shows people in “non-fluoridated Christchurch have “better teeth.” But the graphic is based on naive cherry-picking of the data, it ignores the effect different ethnic groups have on the data and it uses a single cherry-picked year which fits their bias.

On top of that, axis values have been chosen to exaggerate differences and the labels are incorrect. The “non-fluoridated Christchurch” category uses data for Canterbury and the “fluoridated Hamilton” category uses data of the Waikato.

It seems that several of the commenters on the Fluoride Free NZ Facebook page where this graphic was first used saw the problems and raised them. All they got is insults for their time. These organisations do not seem capable of a rational discussion.

The Ministry of Health data they use is freely available on the MoH website. It provides oral health data for 5-year-old children and year 8 children. The data is presented annually and for different regions.

So let’s have a look at what the data really says – using more normal axis ranges and separating out ethnic groups.


The top graph here is still misleading because it does not take into account the effect of different ethnic groups. However, the correct categories are used and the more rational axis really cuts the exaggerated difference down to size.

In the second graphic the data for Māori and Pacifica have been removed – the MoH describes this group as “Other” – it is mainly Pakeha. We can see that the caries-free % is actually greater for fluoridated Auckland than it is for non-fluoridated Canterbury – exactly the opposite of what the anti-fluoride propagandists were claiming.

It is the same story for Māori – the caries-free % is actually higher in fluoridated Auckland than in non-fluoridated Canterbury.

The problem with the “Total” data is that Pacifica have a large effect – particularly in Auckland where Pacifica are concentrated. Pacifica generally have poorer oral health but are concentrated in fluoridated regions. This drives down the caries-free % figures for the fluoridated areas if the differences are not accommodated.

I referred to this effect of Pacifica on the data in my article A challenge to anti-fluoridationers to justify their misrepresentation of New Zealand research. There I was referring to a similar way anti-fluoride campaigners were misrepresenting data from recent New Zealand research. In this case, they were using data from a paper (Schluter & Lee 2016) and completely ignoring the distortions introduced by inclusion of Pacific – even though the authors had warned against the anomaly introduced by this.

There are other effects which should also be considered in a proper understanding of these data. It is easy to cherry-pick the data for a single year when differences are small – the anti-fluoride people do that a lot. OK if you want to confirm your biases but consideration of the data over multiple years helps indicate trends, identify anomalies and provide an idea of variations in the data. It is also important to consider the numbers in each region. For example, I have not included Pacific in the graphs above because they are concentrated in Auckland and the numbers in Canterbury and Waikato are very low (eg., 45 in Waikato in 2014).

Similar articles

Fluoridation: Whakatane teaches us something we should already know


Parliamentary Committee – proper place to discuss attitudes towards community water fluoridation?

So, the Whakatane District Council today reversed its decision to stop fluoridation (see Whakatane fluoride flip-flop). A decision made only a few weeks ago (see Fluoridation: Whakatane District Council makes the Hamilton mistake).  The new vote effectively acknowledges they had made a mistake – a mistake they would not have made if they had paid attention to what happened in Hamilton 2 – 3 years ago.

Well, really two mistakes:

1: Councils should not ignore the democratic will of the electorate without very good reasons. Sure, the referenda in Hamilton and Whakatane were non-binding. But they did represent the will of the people. And the council did not have adequate reasons for ignoring that will.

One difference in Whakatane is that only Ohope and Whakatane itself are fluoridated. The new resolution requests the council to decide whether to fluoridate other areas where the voters supported it – noticeably it effectively accepts the will of those voters opposed to fluoridation where they are a majority in a specific water treatment area.

2: Councils should not be so foolish as to think they can decide the science, or decide health matters. It amazes me that the mayor of Whakatane could acknowledge his council does not have scientific skills – yet he went ahead and got the council to make decisions about the science and health issues involved with community water fluoridation!

Perhaps he would not have done this if there had not been an ideologically and commercially motivated activist group pressuring the council. But that is no excuse.

Would this Mayor have succumbed to pressure from an activist group who disagreed with accepted science and technology of road and bridge building? Of house construction? Or any other matter the council considers. Just imagine what havoc a flat earth society or anti-gravity pressure group could play.

I would hope not. We cannot have such important issues endangered because a group with no skills in the matter takes it upon itself to think it can make decisions about the science, technology and health recommendations. Whatever pressure is coming from activist groups.

It is not the job of councils to decide such matters.

What should councils decide

Yes, they must decide on financial and operational matters involved with these issues. But they don’t get to decide the science and technology. It is hubris on their part to think they can.

Councils do have a role. As operators of water treatment plants they must decide on the financial and working matters. They must decide on the feasibility of specific water treatments.

Under current legislation, they must also take into account the attitudes of their electorate. The government and central health bodies recognise that community water fluoridation can be controversial for some people. Therefore, they encourage local communities to make the final decisions. It is noticeable that where Health Boards seek to extend community water fluoridation they use community consultation and education, including referenda, and do not impose a central demand.

In the end, no matter what the science says or what central health authorities recommend, it is up to communities to make up their minds on a controversial social policy – even if that results in a decision contrary to skilled recommendations.

But councils should not have any role in deciding the science or health policies. The appropriate bodies already do that and they make their recommendations. It is arrogant for councils to think they can, or should, rewrite those recommendations and conclusions about community water fluoridation.

Councils really have nothing to complain about

Councils complain they are being asked to make decisions they are not skilled to make – but that is up to them. If they accepted the conclusions and recommendation of the appropriate central bodies and limited their consideration to financial and working matters which are correctly within their skill set they would have nothing to complain about. Similarly, they should accept the democratic will of their voters on this issue (unless there are good financial or operational matters suggesting otherwise).

Perhaps there is need to remove councils from that assessment of community attitudes towards fluoridation. Let it be done by health boards.

As for the demand that so-called “independent”  or “alternative” groups have an input into decisions – surely the most appropriate place for that is at a central level – the parliamentary health committee or reviews by the Ministry of Health. Such considerations would be less influenced by the childish politics we often see at the local level – especially in election year (which is the case for Whakatane and was also for Hamilton).

Councils should stop sticking their noses into areas they have no authority or skills to make decisions on.

Similar articles

Subverting democratic consultation on the fluoride issue


Credit: Making Sense of Fluoirde

Denver Water, which as Colorado’s largest water provider, has been reviewing its water fluoridation policy. It will announce its decision in the next few days but I found its description of the consultation process interesting.

[Update: Denver Water has now voted unanimously to continue community water fluoridation (see Good News – Denver Water Votes to Continue Community Water Fluoridation!). A complete failure for the anti-fluoride campaigners who worked hard to defeat fluoridation in Denver.]

A spokeswoman for the board, Stacey Chesman said Denver Water had received nearly 1,200 comments, from as far away as New Zealand, with 1,078 opposed to fluoridation, and 663 of those submitting their comments on postcards created by We Are Change Colorado. Every public health agency in Denver Water’s service area urged it to continue fluoridating water (See Water systems sink teeth into debate over drinking it).

Pretty impressive, eh? Twelve hundred submissions and about 90% oppose community water fluoridation (CWF). But look again – over 60% of the opposing submissions were on postcards provided by the anti-fluoride propagandist group “We are Change Colorado.”

Manipulating council consultations

That reminds me of the Hamilton City Council’s fluoride considerations two and a half years ago. That Council’s  summary of submissions reported:

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

The Hamilton numbers are so similar to those in Denver that one might wonder if the same people or organisations organised many of the submissions. And, I suspect, the Denver number of 90% opposed is just as unrepresentative of the public’s view as the Hamilton 90% – as shown by the subsequent Hamilton referendum where 70% of voters supported CWF! (See When politicians and bureaucrats decide the science).

The postcard tactic used in Denver is also much the same as the New Zealand Fluoride Free organisation providing submission templates  (templates A, B, C, D, were used in Hamilton) and submission guides. And the comment that Denver water received submissions “from as far away as New Zealand” also rings a bell – many of the submissions received by the Hamilton City Council were from as far away as the USA. And, in fact, video links were used to enable oral submissions by anti-fluoride propagandists from the USA!

What we have seen in these two cases – and many others in New Zealand, the USA, Canada and Australia – is a highly efficient organised campaign from “out-of-towners” intent on subverting the consultation process and the democratic rights of local citizens. A process which one might think mature and sensible civil leaders could easily recognise and discount. However, some of these leaders are easily fooled. In Hamilton, the local council gave the high numbers of anti-fluoride submissions they got as one of the main reasons for deciding to stop CWF. This seemed to them more important than the real referenda results!

A fluoride referendum in Thames

In New Zealand, the small town of Thames will hold a referendum on fluoridation of their water supply in November (see Thames fluoride referendum set for 5 November). Campaigning will start soon and no doubt we will see the same circus of whirlwind visits from out-of-towners, propaganda from overseas anti-fluoride propagandists (who promote themselves as “world experts” on the subject), and billboard, newspaper and radio advertising – probably paid for by the “natural”/alternative health industry.

I hope the people of Thames will be rightly suspicious of these “out-of-towners,” and ideologically and commercially motived propagandists, and instead listen to the advice of their own social health and dental experts.

Similar articles

Elected officials must ignore activists and listen to own voters


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

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

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

She wrote:

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


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

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

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

Similar articles


There is research and there is “research”


I saw this image on Facebook yesterday and it really resonated with me. I had just been to the Hamilton City Council hearings on their draft annual plan. The anti-fluoride brigade dominated the session.

Many of their submitters proudly declared they had “researched” the subject and found fluoride is really nasty. They were eager to present their “research” findings to the council.

I have long been concerned that many people have cheapened the word “research” by the way they use it. Reading ideologically motivated web sites and magazines is not real research – yet it seems to drive the anti-fluoride community and provide a hubris that they are somehow doing “research.”

By the way, I presented a submission for the making Sense of Fluoride group. Download the linked pdf file if you want to read it.

Similar articles

Fluoridation: What a difference a year makes?


Submissions supporting fluoridation have increased from 11% in 2013 (Hamilton) to 56% in 2014 (Kapiti). Is this a reaction to activist rail-roading of councils?

Has activism on the fluoridation issue shifted dramatically against anti-fluoridationists in the last year?

The number of submissions made to local body councils this year suggest it has.

Last year the anti-fluoridation activists used a national (even international) campaign to overwhelm the Hamilton City Council with submissions opposing fluoridation. Almost 90% of submissions opposed fluoridation – a figure which the council gave as one of its six reasons for deciding against fluroidation.

This year a similar issue in Kapiti sees the situation reversed with anti-fluoridation submissions amounting to less than 44% of the total on fluoridation (see Good response to Draft Annual Plan – Kapiti Council). The Council reported:

“A total of 627 submissions were received on fluoride alone. Of these, 366 were in favour and 261 against fluoride being added to the District’s water supply.”

This apparent decline in anti-fluoridation activism is interesting because activists had been confident of winning another victory in Kapiti. They had campaigned hard to encourage even pro forma submissions from their supporters. Maybe their campaigning effectiveness has declined. Instead they may have to face a far more active and credible opposition than they met in Hamilton last year.

The Kapiti District Council holds their submission hearing days from Tuesday 20 to Thursday 22 May. One hundred and four people have asked to speak about their submissions. These presentations will certainly be interesting.

Perhaps the anti-fluoridation activists have got too cocky after their Hamilton win and didn’t recognise that they may now have a battle on their hands.

Why the change?

It’s probably far too early to draw conclusions  but here are a few suggestions.

1: Hamilton was a wake-up call to many people. Certainly I had not been aware of the situation until hearing the Hamilton Council anti-fluoride vote on the news. Like many people I had expected a referendum and had been waiting for the public discussion to start. I think this shock ended up mobilising pro-science and pro-health people.

2: The public behaviour of anti-fluoridation activists has turned many aware from the ideas. Many of their messages have been so anti-science or straight pseudoscience – this has brought them ridicule. After all, how can one take their message seriously if next week we know they will; be campaigning against vaccinations and chemtrails?

3: The mental gymnastics of anti-fluoride activists denigrating the democratic decision in the Hamilton referendum show a complete disrespect for democratic principles. This turns people off, even many people who may sympathise with anti-fluoridation concerns. Most people accept a democratic decision, no matter what way they vote as individuals.

4: Pro-science and pro-health people have become more active. Public health organisations have an ongoing campaign to extend coverage of fluoridation – particularly into communities which would benefit most. The Hamilton experience has made both public health professionals and pro-science people aware they need to do better.

Similar articles

Fluoridation: Hangout with the University of Waikato

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

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

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

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

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


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


On the University of Waikato Fluoridation in Hamilton Hangout website

The video of the live hangout will be embedded on this page 10 minutes before the event, or you can view and ask questions on the Google+ page –http://bit.ly/1fkzNWe.

The Hangout page advises:

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

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

What if I can’t make it?

They will be uploading the complete hangout to their YouTube channel to watch after it ends:http://www.youtube.com/UniversityWaikato

The panel:

See also:

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

NZ experts deplore anti-fluoridation misrepresentation of science

I usually abhor the concept of science by petition. But I have had a gutsful of devoted anti-fluoridationists assuring me that they have scientific and other experts on their side. And the last straw was the attempt by a local supporter of Fluoride Free Hamilton to get the Waikato University Chemistry Department staff to stop discussing the science of fluoridation. He wanted scientists to opt out of discussing science!

So it was nice to see medical, scientific and technical people respond a little to this. The last issue of Hamilton’s free paper Hamilton News included a list of New Zealand experts who disagree with the anti-fluoridationist claims. The list was whipped up in short time and is not restricted to local people.

The supported statment reads:

“The following medical, scientific and technical experts deplore the misrepresentation of science to support the beliefs of the anti-fluoridation lobby.

The true science of water fluoridation has:

SHOWN that drinking water fluoridation reduces the incidence of tooth decay
NOT SHOWN that drinking water fluoridation has any ill-effects on general health”


Download a sharper version if you wish to check names.

See also:

Similar articles on fluoridation
Making sense of fluoride Facebook page
Fluoridate our water Facebook page
New Zealanders for fluoridation Facebook page

Cherry picking fluoridation data

Anti fluoridationists certianly go in  for picking cherries when the produce “evidence” to discredit fluoridation. Two anti-fluoridatioon actvists, Bruce Spittle and Russel McLean, did this in there opinion piece in the Otago Daily Times recently (see No consent given for fluoridation). In particular, they carefuly selected data from the Ministry of Health’s database on the oral health of children.

How to “prove” fluoridation ineffective

They claimed:

The efficacy of water fluoridation is modest.The Dental School staff referred to the 2009 New Zealand Oral Health Survey which noted that in 2008, for all of New Zealand, the 5-year-olds in fluoridated areas had a percentage caries-free rate of 58.7% compared to the rate of 55.0% for those in non-fluoridated areas. However, the 2011 figures show little difference, with the rate for fluoridated areas being 59.91% and that for non-fluoridated areas being 59.18%.

In this case, while they chose the total data set, they selected just 2 years (2008 and 2011), selected only one age group, considered just “percentage caries-free” and ignored the data for “decayed, missing and filled teeth,” and also ignored the data for Maori (important because these show the influence of social and economic deprivation).

I looked at the whole data set in my article Fluoridation – it does reduce tooth decay. So I will just repeat a few of my data plots from that article toi show the effect of cherry picking. The plots of the data below give an idea of variability and trends. They also show the influence of social and economic deprivation is long-term. (Click on the graphs to enlarge for details).





There could well be some story in the apparent reduction of the effect of fluoridation shown by the % caries free of 5 year olds but that has to be put into the context of the whole data set. It is dishonest to just select the small samples Spittle and McLean did – but of course you can see why they did select those years and restricted their comments to just 5 year olds and “% caries free.”.

How to prove fluoridation damages oral health

The Fluoride Free New Zealand Facebook page provides another example of cherry picking (see Waikato Dental Health Stats). In this case their “findings” were so ludicrous that you might have thought they would blush at presenting them. There are some mistakes in their data, but it tends to show that children had better teeth in the non-fluoridated areas than the fluoridated areas!

Well, they achieved this by cherry picking data for one year (2011) and one region (the Waikato). If we look at some of the data over the availabke time period (2002 – 2011) for Waikato, we can see why they cherry picked this region and year.


But, comparing the Waikato data with the total data in the previous figures we can see a greater variability from year to year. This variability makes any honest comparison very difficult – but it does give opportunities for creative cherry picking. (Yes, I have just “cherry-picked” the caries free data for 5 years old in this graph – but I am making a point).

Be careful of variation and cherry picking

The opportunities for cherry picking in a field like this are everywhere because of the variability. This is not like the data one gets in a carefully controlled laboratory experiment. We are dealing with a biological system – which introduces biological variability. But on top of that, it is also a social system which introduces an extra set of variability.

As an example, I was recently discussing with my granddaughter her new school in Hamilton. She told me that all her friends actually lived out-of-town. But the dental data will have recorded them as being from a fluoridated area because, at the time, Hamilton was fluoridated. Then there are problems of getting consistent evaluation from a large number of dental nurses. Differences in dietary intake, drinking of bottled water, etc., – the list goes on.

Some of this variation “evens out” when the data set is large (and of course has more influence when only part of the data set is chosen. Yes, it would be nice to control for all these social effects but in the real world one rarely gets the opportunity.

However, my point is that the variability introduced into this sort of data by biological and social effects provides ample opportunity for political activists to cherry pick data to support their own story – confirmation bias if innocent and dishonest misrepresentation if not.

So, it is easy to make claims one way or the other in the fluoridation controversy – and to find data to support these claims. But serious assessment of the claims requires critical evaluation of the data – something many people have no experience with.

This seems to have been the case with the Hamilton City Council who concluded from presentations heavily biased toward anti-fluoridationists that fluoridation of water supplies is not effective. But why should we expect city councillors to have the critical evaluation skills required to assess such data? They should never be put in the position of being asked to make scientific judgements in this way.

See also:

Similar articles on fluoridation
Making sense of fluoride Facebook page
New Zealanders for fluoridation Facebook page

Anti-fluoride activists attempt to silence science

Roger Stratford, a local aspiring politician, wants scientist to shut up. He is campaigning against the fluoridation of Hamilton’s water supply (we have a referendum coming up) and is a member of Fluoride Free Hamilton. He is also campaigning for a seat on the Hamilton City Council.

But Roger seems to have a King Canute-like (or is it Walter Mitty-like) perception of his own powers. The Waikato Times this morning reports he wrote to the University of Waikato’s Chemistry Department requesting that it’s staff stop communicating their science (see Anti-fluoride campaigner tries to silence science). He objects to:

“the degree of casual support emanating from the chemistry department in local papers in support of the practice [of fluoridating water] . . . At Fluoride Free Hamilton we intend to limit the debate to the social science and public health aspects of fluoridation. . . . It would be appreciated if we could receive some confirmation from the chemistry department that it will remain publicly neutral on the matter. . . . Fluoride Free Hamilton does not have any issues with the chemistry department academically, it is the implications of modern science in which we differ.”

What a cheek – Fluoride Free Hamilton and Roger Stratford want a deal! They will talk only about social science and the chemists can STFU. Well, we all know that most of the issues around fluoridation are scientific, and mostly chemical. And the anti-fluoridation activists are spreading misinformation about that chemistry as fast and as widely as they possibly can.

What was Roger thinking?

My first whiff of Roger’s stupidity came with a comment of his on the Fluoride Free Hamilton Facebook page:

Facebook-before-2I contacted him asking if he had in fact written to the Chemistry Department. He Assured me in his reply:

“In my experience as a student the chemistry department doesn’t negotiate on anything, it was just a throwaway line of mine to get that Archer fellow from blogging. There is no reason to be alarmed.”

Well, I guess that’s a political answer – an implied but not a factual denial. Mind you, very quickly the comments on the Fluoride Free Hamilton Facebook page changed – see if you can guess what was deleted:


Well, I suppose that is politics. It is really a bit much to expect honesty and integrity from politicians, or from political activists like the Fluoride Free groups.

But I object very strongly to politicians, and political activists, who will do their earnest best to spread misinformation about science – and then tell scientists they have no right to comment on the issues.

See also:

Similar articles on fluoridation
Making sense of fluoride Facebook page
New Zealanders for fluoridation Facebook page