Category Archives: Science

Debating science

The Science March in Palmerston North. Credit: Erin Wilson, Twitter.

This last week has certainly raised the profile of the “science debate” in New Zealand. Most importantly we saw big turnouts for the Science March in several major cities – a demonstration that lots of scientists and supporters of science feel that science could be threatened – or at least that it is unappreciated by the politicians and other decision-makers. Maybe even by a section of the public.

And at the other end of importance, we saw a childish spat by local anti-fluoride activists who had attempted to use a member of Parliament’s experience of miscarriages to make the scaremongering claim that these were caused by community water fluoridation. Then they attempted to divert attention from the embarrassing (for them) widespread condemnation by promoting, through their own press releases,  the fake news they had organised a “TV debate” on fluoridation with a local scientist.

The Science March

The Science March was many things to many people. I saw it as a general demonstration of support for science and opposition to attempts to discredit science – examples being the science around climate change, vaccinations, evolution – and yes even fluoridation. Some of the media presented it as a demonstration against US president Trump and his policies – and there may have been many in the US Science Marches who had these motivations. But every country and every region have examples where politicians have downplayed scientific evidence or even attempted to discredit that evidence and the scientists who produced it. These sort of struggles went on long before Trump and they will go on after Trump.

For example, in New Zealand, we have some specific issues over water quality and climate change which are quite unconnected to the US and its politicians. We have to fight out those issues here. Scientists, anyway, strongly resist linking their issues to politics and political movements. We have had a few bad experiences from that. This resistance and the silly intervention of identity politics into the organisation of the US Science Marches did make many scientists wary of participation.

But, in the end, the Science Marches around the world had good turnouts and my impression is that participants felt they had been both worthwhile for science and good experiences personally.

Of course, the Science March will not make the problems go away. There is still a need for the day to day struggle on issues like climate change, water and environmental quality and even fluoridation. This is one of the points I attempted to make in my article Trump didn’t invent the problems – and his opponents didn’t invent protest.

Debating science

And this is where a continuing debate around science issues is important. To be clear – I am not using the word “debate” in the formal sense (more on that later) but in its most general sense. And not necessarily debate involving specific contact between adversaries.

Issues about water quality and the environment come up continually in New Zealand. In the media, in local body and parliamentary considerations, and in government statements. A lot of the commentary may downplay the science on the issue or overplay economic and financial aspects. Some of the commentaries may be outright anti-science – or present misinformation, even distortions, about the science. Activist claims about the “dangers” of the use of 1080 to control predator pests are an example.

The misinformation and downplay of scientific information cannot be allowed free passage – it must be challenged. Hence there is a debate – again not a formal debate, but a debate, nevertheless. The public is exposed to various claims and counterclaims via the media and the internet. Regional bodies and parliamentary committees are deluged with submissions and scientists and supporters of science have a role to play there too.

Scientists and supporters of science should not stand aside and let the opposition win by default – simply because they abhor the political process or ego-driven participation in media reports. But they need to choose their battles – and they need to consider the effectiveness or otherwise of different forms of participation in public debate.

Problems with formal debates

So what about formal debates of the sort the Fluoride Free New Zealand (FFNZ – the local anti-fluoride organisation) claimed via their press releases to have organised? A TV debate between New Zealand Scientist Professor Michelle Dickinson from Auckland University, and Dr. Paul Connett – chief guru at the US Fluoride Action Network. This proved to be a kickback from FFNZ, a diversion from the bad publicity that came their way when Dickinson publicly criticised their use of scaremongering tactics in an email sent to a Green member of parliament. Public commenters were disgusted at the FFNZ claim the miscarriages she had suffered were caused by community water fluoridation.

Professor Dickinson pointed out she had not agreed to a TV debate (which FFNZ then childishly used in another press release to claim she had reneged). And Dr. Paul Connett did not even publicly respond – indicating that while the debate challenge had been made in his name he knew nothing about it.

Kane Titchener, the Auckland FFNZ organiser who made the challenge to Michelle Dickinson, is a bit of a Walter Mitty character and often makes debate challenges in Paul Connett’s name, but without his authorisation. These challenges are his way of avoiding the discussion of the science when he is outgunned. He made a similar challenge to me four years ago – I called his bluff and nothing happened. The debate I did eventually have with Paul Connett was arranged through Vinny Eastwood (a local conspiracy theorist who promote anti-fluoride propaganda), not Kane Titchener – who was probably not even in contact with Connett.

But, in general, scientists are unwilling to take part in the sort of formal debates Kane Titchener was proposing. There are often similar challenges made to evolutionary scientists by creationists and religious apologists, and to climate scientists by climate change deniers. Scientists generally feel their opposition make these challenges in an attempt to gain recognition or status they do not deserve. (I think in this particular case Kane Titchener may have naively thought he could use Michelle Dickinson’s connections with TV personalities to get Connett on TV – something he has found impossible on his recent visits to NZ).

Another, more important, reason is that such formal debates are usually more entertainment than information. In fact, debating is a recognised form of entertainment often driven by egos and aimed at ‘scoring points’ which appeal to a biased and motivated audience. They are rarely a way of providing information and using reasoning to come to conclusions – which is the normal and accepted process of scientific discussion.

Good faith discussion

Don’t get me wrong – I am not opposed to all forms of one-on-one “debate” or discussion. These can be useful – especially when the audience is not stacked by biased activists. An exchange of scientific views or information in front of an interested but unbiased audience can be a useful and good experience.

Similarly on-line, written debates or discussion of the sort I had with Paul Connett in 2013/2014 can also be useful (see Connett & Perrott, 2014. The Fluoride Debate). In this format, ego and debating or entertainment skills are less effective. Participants need to produce information – and back it up with evidence, citations or logic. And one’s discussion partner always has the opportunity to critically comment on that information.

I feel that debate was successful – it enabled both sides to prevent information in a calm way without put downs or ego problems. I often use that debate when I want to check out citations and claims. Interestingly, though, Paul Connett behaves as if the debate never happened – claiming that no-one in New Zealand has been prepared to debate him. The FFNZ activists do the same thing. Ever since that debate, I have been blocked from commenting on any anti-fluoride website or Facebook page in New Zealand and internationally. It’s almost as if some sort of Stalinist order went out to treat me like a “non-person.”

A challenge to anti-fluoridation activists

If these activists are so keen on debating the issue then why don’t they allow it to happen? Why do they block pro-science people from commenting on their Facebook pages? Why do they ignore open letters and offers of rights of reply of the sort I sent to Stan Litras and other anti-fluoride activists (see A challenge to anti-fluoridationers to justify their misrepresentation of New Zealand research). Why did Lisa Hansen – the solicitor for the NZ Health Trust who has been making incorrect scientific claims in her High Court cases opposing fluoridation ignore my offer of a right of reply (see Open letter to Lisa Hansen on NZ Fluoridation Review)? Even the “great helmsman” himself, the man who Kane Titchener seems to think will answer all the questions, refuses to respond to offers of right of reply (see Misrepresenting fluoride science – an open letter to Paul Connett).

Why do these people ignore such opportunities?

One thing I noticed about the submission made by opponents of community water fluoridation to the recent parliamentary Health Committee consideration of the Fluoridation Bill was the overwhelming reliance on scientific claims in almost all their submissions. Claims that fluoridation causes IQ loss, fluorosis and a whole host of sicknesses. Many of the submitters actually used citations to scientific journals or attached copies of scientific papers.

These people claim they have science on their side – yet they seem to be extremely shy about discussing that science in any open way. Why is that?

No, it’s not a matter of Walter Mitty types making debate challenges in the name of Paul Connett. Why don’t Kane Titchener, Mary Byrne, Stan Litras, Lynn Jordan (alias Penelope Paisley on Facebook) and similar activists who love to make “authoritative” scientific claims in submissions or behind the protection of a ring-fenced Facebook page or website participate in an honest open debate?

For a start – what about stopping these silly”challenges” in Paul Connett’s name. Then they could remove restrictions on the discussion on the websites and Facebook pages they control.

And, yes, I would be happy for them to participate in good faith scientific discussion in articles on this blog. That is what my offers of the right of reply to my articles were all about.

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Rio Olympics – what are those gold medals worth?

Medals

Well, that’s a surprise.

Those gold medals athletes are working hard for at the Rio Olympics are not pure gold – just gold-plated silver. In fact, the of the Rio Olympics gold medals is 98.8% silver and only 1.2 % gold.

According to Compound Interest (The Composition of the Rio Olympics Medals):

“Giving out pure gold medals would be financially crippling for the International Olympic Committee, so unsurprisingly some compromises are involved.”

Olympic gold medals haven’t been 100% gold since the 1912 Olympics in Stockholm.

“Since then, they’ve actually been mainly made of silver, with a gold plating on top to give them the expected appearance.”

“Compositions are variable at different Olympics; for example, at the London 2012 Olympics the gold medals consisted of gold (1%), silver (92%) and copper (7%). The value of the Rio Olympics gold medal, based on its metal composition, is approximately $565. Contrast this with their value if they were composed of pure gold: their current market value would be $21,200!”

Seems like a lot of work is involved in moving from second to first place just for a thin plating of Gold.

Still, it’s the thought that counts.

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Dental health – it’s not all about fluoride

cross-section-of-tooth

Fluoride is not the only element involved in preventing decay. See Fluoridation – topical confusion  for a description of how fluoride, calcium and phosphate react at the tooth surface.

Fluoride is not the only factor in oral health. But it is generally the only element in drinking water considered for its effect on our teeth.

Drinking water fluoride benefits existing teeth by chemically reacting with the tooth surface. Involvement of fluoride in the apatite structure at the tooth surface helps prevent demineralisation, due to acid attack, and also encourages remineralisation – tooth enamel repair.

But fluoride is not the only chemical species in drinking water and food that promotes this reaction at the tooth surface. Calcium and phosphate must also be involved. (Bioapatites in teeth and bones are chemical compounds of calcium, phosphate and fluoride). However, these other ions have generally been neglected in studies of the effects of drinking water composition on dental health.

I recently came across a scientific paper which helps overcome this deficiency:

Bruvo, M., Ekstrand, K., Arvin, E., Spliid, H., Moe, D., Kirkeby, S., & Bardow, A. (2008). Optimal Drinking Water Composition for Caries Control in Populations. Journal of Dental Research, 87(4), 340–343.

It compared the dental health of Danish children with the most significant drinking water characteristics. Data for the decayed missing and filled tooth surfaces (DMF-S) of 15 year old schoolchildren were used.  The drinking water characteristics included the concentration of a range of cations and anions, organic carbon, hardness, pH, ionic strength and residue content.

Statistical analysis identified calcium and fluoride as having the major effect and the authors used their data to produce a model relating DMF-S to both calcium and fluoride. The figure below give some idea of predictions from this model.

Ca and F

The model explains about 45% of the variance – better than when fluoride is considered alone (Ekstrand et al., 2003 were able to explain 35% of the variance using fluoride alone).

Community water fluoridation is not used in Denmark but the natural concentration of fluoride in the drinking waters reported in this study ranged from 0.06 – 1.61 (mean 0.33) mg F/L. The concentration of calcium ranged from 31.4 – 162.3 (mean 83.5) mg Ca/L.

So, a result that is hardly surprising for chemists familiar with the surface chemistry of apatites. But it does suggest that perhaps health authorities should consider the calcium concentration of drinking waters as well as fluoride.

According to the authors optimal drinking water should contain medium concentrations of both ions – about 90 mg Ca/L and 0.75 mg F/L. I suspect our drinking water calcium concentrations in New Zealand tend to be lower than this.

Perhaps this is something to think about. And perhaps those anti-fluoride fanatics who use distillation or reverse osmosis to remove fluoride are also forgoing the oral health benefits of calcium. A case of throwing out two babies with the bath water.

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Why the internet annoys chemists

Here are some of chemist’s pet peeves chemists about discussion on social media and the internet in general. The list is from the article  5 simple chemistry facts that everyone should understand before talking about science posted on the blog The Logic of Science.

Everyone who has attempted to discuss issues like vaccination or fluoridation with opponents will have come across these arguments which the author describes as “based on a lack of knowledge about high school level chemistry.” This ignorance doesn’t seem to prevent the perpetrators of these arguments presenting with extreme confidence and fervour. When challenged they often question the scientific credibility of their critics and urge them to “do some research!”

1: Everything is made of chemicals

chemical free

The article points out:

“This seems like a simple concept, but many people seem to struggle greatly with it, so let’s get this straight: all matter is made of chemicals. You consist entirely of chemicals. All food (even organic food) consists entirely of chemicals. Herbal remedies consist entirely of chemicals, etc. So, when someone says something like, “I don’t vaccinate because I don’t want my child to be injected with chemicals,” they have just demonstrated how truly uninformed they are, and you can be absolutely certain that they don’t know what they are talking about because all matter is made of chemicals.”

Yet these arguments and terms like “chemical-free” seem to have gripped public consciousness. The only thing “chemical-free” is empty space!

A particular peeve of mine is the attitude advertisers seem to have that by declaring their product “chemical-free” they can get away with not identifying the real chemicals in their product. Recently at the supermarket I searched in vain for an indication of the chemicals in a package of sea salt. Genuinely intrigued to find what other salts were present, together with the majority sodium chloride, all I could find was the description that the product was “chemical-free!”

2: The dose makes the poison

sense-about-science

“There is no such thing as a toxic chemical, there are only toxic doses. Let me say that again: all chemicals are safe at a low enough dose, and all chemicals are toxic at a high enough dose. This is a fundamental fact that people in the anti-science movement routinely ignore.”

Yet look at how the anti-science movement ignores this simple fact. Anti-fluoridationists who seem to think that have a foolproof argument by waving Material Safety Data Sheets for water treatment chemicals like fluorosilicic acid and sodium fluorosilicate. Such sheets supply information for people manufacturing, handling and transporting the concentrated chemical. They have absolutely no relevance for the person drinking the water coming out of their tap.

A little more sophisticated (although only a little) are the arguments based on scientific studies of rats administered chemicals at concentrations far higher than confronted by the ordinary consumer. Anti-fluoridationists spout so  much hot air citing studies of rats administered 100 ppm F or more in their drinking water to claim that drinking fluoridated water which has an F concentration of 0.7 ppm is harmful!

“The importance of this fact cannot be overstated. No chemical is inherently safe or inherently dangerous. So, the next time that someone tries to scare you about the “toxic chemicals” in your food, medicine, vaccines, detergents, etc. ask them for two pieces of information:

  1. What is the toxic dose in humans?
  2. What is the dose in the product in question?

Those two pieces of information are absolutely crucial to evaluating the safety of the product. You simply cannot know whether that chemical is dangerous without knowing the dose in the product and the dose at which it becomes toxic.”

3: There is no difference between “natural” and “synthetic” versions of a chemical

“I often hear people claim that “synthetic” chemicals (a.k.a. chemicals made in a lab) are not as good for you as their “natural” counterparts. The reality is that this represents a misunderstanding of literally the most fundamental concept of chemistry. The most basic unit of matter is the atom, and there are several different types of atoms known as elements. We combine these elements to make various molecules, and the combination of elements determines the molecule’s properties. The process by which those elements were combined is completely and totally irrelevant to how the final chemical behaves.

For example, water (a.k.a. dihydrogen monoxide) consists of three atoms: 2 hydrogens and 1 oxygen (hydrogen and oxygen are both elements). There are literally thousands of different chemical reactions that will produce water. In other words, we can make water thousands of different ways, but water always behaves in exactly the same way no matter how it was formed because it always consists of the same three atoms. Further, if given a vial of pure water, there isn’t a chemist anywhere in the world who could tell you how that water was produced because it would be completely identical to all of the other water everywhere on the planet. So, as long as the chemical structure is the same, it doesn’t matter if the chemical was extracted from a plant or synthesized in a lab.”

Yet, how often am I told that fluoridating chemicals are bad because they are “industrial,” “manufactured” or “synthetic.” The implication being that if we just dug these minerals out of the ground and dumped them in the water things would be quite OK. Of course, these people ignore the impurities present in “natural” ores and chemicals. Purification to a standard suitable for use in foods and drinking water requires chemical processing. Does treatment converting an “unsafe” ore or chemical to a safe (for consumption) chemical somehow make the chemical unsafe because it is now synthetic?

4: “Natural” chemicals are not automatically good and “artificial” chemicals are not automatically bad

“I often encounter people who will claim to agree with everything that I have said thus far, but they still insist that “artificial” chemicals (a.k.a. chemicals that simply are not found in nature) are bad for you and shouldn’t be consumed, injected, etc. There are several critical problems here. First, remember again that all chemicals are dangerous at a high enough doses and safe at a low enough dose. That is just as true for artificial chemicals as it is for natural chemicals. Second, this claim is nothing more than an appeal to nature fallacy. Nature is full of chemicals such as cyanide and arsenic that are dangerous at anything but a very low dose, so there is no reason to think that the “naturalness” of a chemical is an indicator of its healthiness.

Further, remember that chemicals are nothing more than arrangements of elements. There is absolutely no reason to think that nature has produced all of the best arrangements or that we are incapable of making an arrangement that is safe or even better than what nature produced. I constantly hear people say that we cannot improve on nature, but that is an utterly ludicrous and unsupportable claim, and I would challenge anyone to give me a logical syllogism that backs it up. Really think about this for a minute, if you are of the opinion that artificial chemicals should be avoided, try to defend that position. Ask yourself why you think that. Can you give me any reason to think that they are bad other than simply that they aren’t natural (which we have just established is a fallacy)?”

This nature = good, articifial=bad,  argument may appeal to the emotions of the chemo-phobic consumer, but it is just not rational.

5: A chemical’s properties are determined by the other chemicals that it is bound to

This is so obvious to anyone who has a rudimentary understanding of chemistry – but surprisingly it still gets challenged. How often have I come across anti-fluoride campaigners referring to fluorine containing chemicals like sarin gas (a chemical weapon), Prozac (a drug), hydrofluoric acid (a corrosive acid) – or even to fluorosilicates (used to treat water but decomposing on dilution) as if their properties were relevant to the fluoride in drinking water.

“Chemical compounds are made by combining different elements or even molecules, and the final product may not behave the same way as all of its individual parts. Sodium chloride is a classic example of this concept. Sodium is extremely reactive and will literally explode if it contacts water, and chlorine is very toxic at anything but an extremely low dose. Nevertheless, when we combine them we get sodium chloride, which is better known as table salt. Notice that table salt does not have the properties of either sodium or chlorine. It does not explode when it contacts water and you cannot get chlorine poisoning from it no matter how much of it you eat. The combination of those two elements changed their properties and it would be absurd to say that “salt is dangerous because it contains sodium.” The sodium in salt no longer behaves like sodium because it is bound to the chlorine. Therefore, when you hear a claim that something contains a dangerous chemical, make sure that the chemical isn’t bound to something that makes it safe.”

And therefore:

“So, claiming that “mercury is dangerous and vaccines contain mercury, therefore vaccines are dangerous” is no different from claiming that “sodium is dangerous and salt contains sodium, therefore salt is dangerous.””

Most dangerous and toxic  chemicals contain hydrogen, carbon, oxygen and/or nitrogen. That doesn’t make pure water toxic because it contains oxygen and hydrogen. Proteins, starches and sugars toxic because they contain hydrogen, oxygen carbon and nitrogen. Or the air we breath toxic because it contains oxygen and nitrogen.

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Image

Monday morning proverb

truth

Anonymous comments on social media

IMG_0666

 

Something I picked up on the internet.

Yes, I know – some people have legitimate and understandable reasons for being anonymous when they comment on social media. Concern for jobs and protection for family and self.

I can appreciate that and have no issue with those people.

But there is just such a lot of rubbish spouted by anonymous commenters on social media. I can only conclude the reason for anonymity of these hostile and drive-by commenters is that they are at least subconsciously aware of the rubbish they are promoting so do not want their name associated with it.

Whatever their reason, anonymity seems to bring out the worst in these people. and they waste a lot of time for others who attempt to debate them.

Are submissions on fluoridation worth it?

Like most people I struggle to find the energy when representative and government bodies call for submissions. But I did make the effort recently when Medsafe called for submissions on their proposed clarification of how fluoridating agents are defined in the medicine regulations. I am pleased to see the simple suggestion I made was accepted. But my purpose here is to illustrate how this consultation proceeded and how opponents of community water fluoridation (CWF) tried to swamp it with their submissions.

The background

Last November the Ministry of Health (MoH), through Medsafe, called for submission on a change to the Medicine Regulations 1984. This change had been recommended by the High Court and the Crown Law Office who specifically suggested that fluoride compounds used for CWF be exempt from definition as a “medicine.” This arose from the defeat of attempts by an anti-fluoride group, New Health NZ, to use the argument that fluoridation was medication in the High Court actions against CWF. Despite these defeats the High Court and Crown Law Office considered the regulations should be clarified to remove the argument from repeated litigation.

Simply, the proposal was to add a new regulation:

“Fluoride-containing substances, including the substances hydrofluorosilicic acid (HFA) and sodium silico fluoride (SSF) are not medicines for the purposes of the Act when they are manufactured and supplied or distributed for the purpose of fluoridating community water supplies.”

Medsafe asked for responses to the following questions:

  • Question 1: Do you support the proposed amendment? If not why not?
  • Question 2: Are there other fluoride-containing compounds used to treat community water supplies that should be specifically named in the regulation? If so, what are they?

Submissions – quantity or quality

The report from MoH on the process and their recommendations to cabinet give an idea of the submissions made and the final decision.

As we might expect from past experience the submissions were dominated, in numbers if not quality and relevance, by those from the anti-fluoride groups. They had organised a national and international campaign to swamp Medsafe. Paul Connett’s Fluoride Action Network, Fluoride Free NZ and New Health NZ even provided texts and templates to copy and paste into submissions.

Here is the description of the consultation outcome in the MoH report:

MOH-report-extract

So, the activist organisations can certainly mobilise their forces for submissions. But concentration on numbers and not content – and cynical provision of content to followers anyway – didn’t win them any credence. Did they really think blatant duplication of submissions would not stick out like a sore thumb?

It is also heartening to see that the MoH was not swayed by blanket repetition of arguments which do not have credible scientific support. (I guess we can also see why the anti-fluoride activists groups are putting so much effort into their campaign to attack and discredit the NZ Fluoridation Review which summarises the scientific evidence.)

Sometimes suggestions are accepted

I had made the simple suggestion tha sodium fluoride be added to the short list of examples of fluoride chemicals used for CWF. So this recommendation to cabinet pleased me

recommend-to-cabinet

Nice to know that the consultation was not a sham and that reasonable and credible suggestions were listened to and even accepted. It is worth making submissions even when one is aware they me in a minority. If something is worth saying it should be said despite attempts by others to confuse issues.

Also nice to know that some consultations are not simply swayed by quantity and not quality – as was the case for the Hamilton City Council fluoride consultation in 2013 (see When politicians and bureaucrats decide the science).

The Hamilton City Council consultation also showed an extreme naivety in the Council’s willingness to ignore the established science. I wonder what approach they would have taken if the NZ Fluoridation Review had been available at the time?

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Severe dental fluorosis and cognitive deficits – now peer reviewed

peer-review-cartoon
Last May I raised the possibility that the much touted relationship of small IQ declines for children living in areas with naturally high fluoride in drinking water could be associated with severe dental fluorosis and not a chemical neurotoxicant (see Confirmation blindness on the fluoride-IQ issue). In November I repeated this argument because the recently published work by Choi et al (2015) provided evidence of a statistically significant relationship of cognitive deficits to severe dental fluorosis for Chinese children living in high fluoride areas  (see Severe dental fluorosis the real cause of IQ deficits?).
I am pleased to report the journal Neurotoxicology and Teratology (which published the Choi et al., 2015 paper) have now accepted a peer-reviewed letter to the Editor from me on the subject:

Perrott, K. W. (2015). Severe dental fluorosis and cognitive deficits. Neurotoxicology and Teratology.

Don’t limit possible hypotheses

My letter warns:

“cognitive deficits could have many causes or influences – genetic, environmental and/or social. Researchers need to be careful not to limit their possible hypotheses or research approaches. Unfortunately Choi et al. (2015) appear to be doing just this with their plans for a larger scale study targeted only at “fluoride’s developmental neurotoxicity.””

It points out:

Choi et al. (2012) did highlight the need for further research. Broadbent et al. (2014) showed no effect of fluoride on IQ at the optimum drinking water concentrations used in CWF [community water fluoridation]. However, most of the reports reviewed by Choi et al. (2012) considered data from areas of endemic fluorosis where drinking water fluoride concentrations are higher.”

“Choi et al. (2015) did not find a statistically significant association of drinking water fluoride concentration with any of the neuropsychological measurements. But they did find one for moderate and severe dental fluorosis with the WISC-R digit span subtest.”

This suggests a possible hypothesis involving the effects of negative physical appearance and not a chemical neurotxocant:

“Emotional problems in children have been related to physical anomalies, including obvious oral health problems like severe tooth decay (Hilsheimer and Kurko, 1979). Cognitive deficits can sometimes be related to emotional problems and subsequent learning and behavior problems. Quality of lifeparticularly oral health related quality of life – is negatively related to tooth decay and severe dental fluorosis. It is possible that negative oral health quality of life feelings in children could induce learning and behavior difficulties which are reflected in neuropsychological measurements.”

Difference between areas of endemic fluorosis and CWF

This hypothesis is applicable to children in areas of endemic fluorosis but is not relevant to areas where CWF is used:

“Sixty percent of the children in the Choi et al. (2015) pilot study had dental fluorosis graded as moderate or severe. This likely reflects the endemic fluorosis of the study area. Only a few percent of individuals in areas exposed to the optimum levels of drinking water fluoride used in CWF have dental fluorosis that severe. For example, a recent oral health survey in New Zealand found 2% of individual had moderate dental fluorosis and 0% had severe dental fluorosis (Ministry of Health, 2010). Similarly a US survey found only 2% of individuals exhibited moderate dental fluorosis and less the 1% severe dental fluorosis (Beltrán-Aguilar et al., 2010).”

“Tooth decay and other oral defects negatively impact a child’s quality of life as assessed by children and parents (Barbosa and Gavião, 2008; Nurelhuda et al., 2010; de Castro et al., 2011; Aguilar-Díaz et al., 2011; Biazevic et al., 2008; Abanto et al., 2012Krisdapong et al., 2012; Bönecker et al., 2012; Locker, 2007). Quality of life impacts have also been found for dental fluorosis, but there is a marked difference in physical appearance and quality of life assessments for children with moderate/severe dental fluorosis compared with those having none/questionable or very mild/mild forms.

The physical appearance of moderate and severe forms of dental fluorosis is generally considered undesirable so we could expect these forms to be associated with poor quality of life and this appears to be the case (Chankanka et al., 2010; Do and Spencer, 2007; Chikte et al., 2001). In contrast, most studies report no effect or a positive effect of questionable, very mild and mild forms of dental fluorosis on quality of life (Do and Spencer, 2007; Chankanka et al., 2010; Peres et al., 2009; Biazevic et al., 2008; Büchel et al., 2011; Michel-Crosato et al., 2005).

Given the different patterns of dental fluorosis severity in areas of endemic fluorosis and areas where CWF is practiced and fluoride intakes are likely to be optimal it seems reasonable to expect a difference in ways fluoride intake influences health-related quality of life and possibly cognitive factors.”

My purpose in this letter was to argue that other mechanisms besides chemical neurotoxicity should be considered in these studies. I hope researchers take this on board and look forward to the response of Choi and her co-workers to this suggestion.

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“Do your own research!”

How many times have I had discussion partners on the internet say to me “Do your own research?”

Inevitably they are pushing some pseudoscientific or anti-scientific conspiracy theory – yet claiming science is their friend!

Here, one of the members of Paul Connett’s Fluoride Action Network team ( Carol Kopf, Media Director who uses the Twitter name @nyscof) tells critics to do their own research – internet research:

And if you type in fluoride adverse effects, you get 270 results

Well, I followed her advice and got this:

Fluoride adverse effects – PubMedScreenshot-fluoride

But unlike Carol Kopf I naturally didn’t stop there – I also typed in “water adverse effects” and got this:

Water adverse effects -PubMed
Screenshot-water

She has a really funny understanding of what the word research means.

Imagine if she followed her implied advice and refused to consume water because of all its adverse effects!

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Let’s rely on anecdotes instead!

anecdote
Image credit: Saturday Morning Breakfast Cereal.

This satirical piece from The Shovel highlights an unfortunate way many politicians (mainly US and Australian)  and internet propagandists approach scientific matters – relying on anecdotes and not evidence. It is also true of many blog commenters.


Science To Be Replaced By Anecdotes

Australia’s scientific research programs will be cut back and replaced by a recent experience the guy down the shops had, it was revealed today. A government spokesperson said it was a move to a more common-sense approach to research and development. “Roger, who I bumped into just the other day, told a pretty pertinent story about how he’d seen first hand just how powerful anecdotes can be,” the spokesperson said. “I think it would be unwise and, frankly, disrespectful, to dismiss his opinion out of hand”.The spokesperson said the Coalition wanted to avoid the dangerous precedent set by previous Governments whereby science was left to professionals and experts. “Scientists have a right to an opinion too. But let’s not forget the various other equally valid views and opinions in the community”.

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