Category Archives: science

Fascinating and painless chemistry lessons


I had to select this video on the element rutherfordium because of the  New Zealand link of the scientist the element is named after.

It’s an interesting short lesson on rutherfordium and there is more where it came from – in fact one short video lesson for every element in the periodic table! Click on the image below to go to the interactive version of the periodic table.

PeriodicTable

 

You can find out more about the people who produced these videos from this University of Nottingham web site – Periodic Videos

This is a great, painless, way to learn some interesting chemistry.

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Did the Royal Society get it wrong about fluoridation?

Did the Royal Society of NZ and the Office of the NZ Prime Minister’s Chief Science Advisor make a big mistake in their report Health Effects of Water Fluoridation: a Review of the Scientific Evidence)? Did they misrepresent a scientific paper which reported an effect of fluoride on the IQ of children?

This is what “Connett’s Crowd,” anti-fluoridation activists and propagandists, are saying in their attempts to discredit the review. So, did this review make the mistake its critics claim?

Well, no. It’s just a beat up. But there is a small mistake in the review’s executive summary which the anti-fluoridationists are pouncing on.

The issue

Most critics of community water fluoridation rely heavily on this paper:

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

This was a metareview of mainly obscure and brief reports (see Quality and selection counts in fluoride research) indicating the possibility the fluoride intake by children living in high fluoride areas of China and Iran may suffer IQ deficits. Choi et al., (2012) used a statistical analysis to determine the possible size of the IQ drop averaged over all the studies. They found a small drop and said:

“The estimated decrease in average IQ associated with fluoride exposure based on our analysis may seem small and may be within the measurement error of IQ testing.”

Their abstract reported the:

“standardized weighted mean difference in IQ score between exposed and reference populations was –0.45 (95% confidence interval: –0.56, –0.35).”

(Their use of “standardised weighted mean difference” was poorly explained and has caused confusion with many readers. See below for a brief explanation of the term).

What did the Royal Society Review say about this?

The review discusses the question of possible neurotoxic effects on page 49-50. Their comment relevant to Choi et al., (2014) appears below (click to enlarge):

review1

And this is what is in the executive summary (click below to enlarge). It makes a very small mistake by referring to “less than one IQ point” when it should have said “less than one standard deviation.”

review2

So, the review reported the Choi et al., (2012) findings accurately but made a small mistake in the executive summary. This is really of no consequence because the overall message of the small size of the estimated IQ drop (described by the authors as “small and may be within the measurement error of IQ testing”) is not really altered.

What do the anti-fluoride critics say?

Such mistakes are inevitable and authors will universally say they usually find them only after publication when no correction is possible. I remember picking up 5 mistakes in one of my papers – mainly incorrect spelling of my own name several times and a mistake in the address of my institution – those were the early days of word processing! Of course no one used my mistakes to cast doubts on the scientific content of the paper.

Still, “Connett’s crowd” have been merciless in their criticism. Here is an example from the big man himself (see Water Fluoridation: The “Healthy” Practice That Has Deceived the World):

Gluckman and Skegg (sic)* mistakenly claim “a shift of less than one IQ point” in the 27 studies reviewed by Choi et al. (2012). What they have done here is to confuse the drop of half of one standard deviation reported by the authors with the actual drop in IQ, which was 6.9 points. Such an elementary mistake would not have been made by Gluckman and Skegg (sic)* if they had actually read the report, instead of relying on what fluoridation propagandists were saying about it.

* Of course Gluckman and Skegg – who Connett calls The ‘Hollow Men’ of New Zealand –  did not author this review.

H.S. Micklem, in the Fluoride Free NZ report on the Royal Society review, snipes:

“It is hard to imagine how this mistake could have been made by anyone who had actually read the papers that are disparaged so casually.”

I guess critics should read carefully before indulging in such snaky comments. All they have demonstrated is that they did not read past the executive summary of the review (and certainly did not read the relevant section in the review). Or, more seriously, that they wish to misrepresent the review by highlighting the mistake and ignoring what the review actually says.

(At Least Kathleen Thiessen was more honest in her comments in the FFNZ report because she did refer to page 49 as well as the mistake. However she still concluded “The RSNZ report is not accurate in its characterization of the Choi et al. (2012) article on effects of fluoride on children’s IQ.”)

Update: One of my commenters, picker22, has brought this to our attention – it puts the mistake mentioend above into context.

“The original press release from Harvard School of Public Health News service made the same error stating that the difference was .5 IQ points. This error on the part of Harvard led to more that a couple of mis-statements by fluoridation advocates in the US.

The current web page notes that the sentence reporting the magnitude of IQ change was “updated” Sept 5, 2012. Sadly, I didn’t copy the original.

http://www.hsph.harvard.edu/news/features/features/fluoride-childrens-health-grandjean-choi.html

Is Choi et al (2012) relevant to fluoridation?

Not really.

The only study specific to community water fluoridation (CWF) the Royal Society review mentions is Broadbent, et al., (2014). Community Water Fluoridation and Intelligence: Prospective Study in New Zealand.

The Choi et al., (2012) paper reviews reports mainly from areas of endemic fluorosis where fluoride intake is much higher than areas using CWF. Subsequently the same authors  made their own measurements in a similar area of China and did not find a significant relationship of drinking water fluoride to IQ (see Choi et al., 2014. Association of lifetime exposure to fluoride and cognitive functions in Chinese children: A pilot study).

The did, however, find a relationship of IQ to severe dental fluorosis. I discuss their findings in my article 

What is this “standardised weighted mean difference”

This term caused a lot of confusion with readers and critics. Choi et al., (2012) used this statistical device because they were attempting to estimate the average decrease in  IQ associated with fluoride exposure based on the difference in IQ between children from high fluoride villages and low fluoride villages in a large number of studies. Further, different IQ scales and measurement methods were used in the different studies which had different levels of variation in the data.

They therefore standardised the differences by expressing them as a fraction of the standard deviation for each study. A mean value over all studies was determined, weighting the contribution from each study according to the precision of the IQ measurements.

The standardised weighted mean difference value of 0.45 has meaning because we know it represents less than half of one standard deviation so it gives us an indication of how it compares with measurement error. But a value of 6.9 as used by Paul Connett is meaningless – until we are told the standard deviation. Choi et al. (2012)  did not report a difference of 6.9 implied by Paul Connett who appears to have obtained that value from a response to a letter to the editor where they use a hypothetical example to explain the meaning:

“For commonly used IQ scores with a mean of 100 and an SD of 15, 0.45 SDs is equivalent to 6.75 points (rounded to 7 points).”

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Cherry-picking and misinformation in Stan Litras’s anti-fluoride article

This is the second article in a series critiquing contributions to the Fluoride Free NZ report Scientific and Critical Analysis of the 2014 New Zealand Fluoridation Report.”

My first article Peer review of an anti-fluoride “peer review”  discussed Kathleen Theissen’s contribution. (It also discussed a draft contribution by Chris Neurath which does not appear in the final version).

I will shortly post a 3rd article discussing H. S. Micklem’s contribution.

See The farce of a “sciency” anti-fluoride report for an analysis of the close relationships between the authors and peer reviewers of the Fluoride Free report and anti-fluoride activist groups.


There is a lot in Stan Litras’s article to criticise – there is a lot which is misleading or outright wrong. I hope Stan will seriously consider my criticisms and respond to them, especially where he thinks I am wrong.

My criticisms should also be considered by Bruce Spittle and Hardy Limeback who Fluoride Free NZ listed as “peer reviewers” of Stan’s article. They must bear some responsibility for allowing the article to go ahead without the necessary corrections.

Litras makes many of his criticisms of community water fluoridation (CWF) in passing – without argument or evidence. But he declares:

“My comments will focus on the gross over statement of the purported benefits of fluoridation in our society, New Zealand, 2014.”

So, I will start with the claims he makes on this.

“Overseas studies” – The WHO data

Central to this are Stan’s assertions:

“The “elephant in the room” is that while decay rates fell in areas where fluoridation was implemented, it also fell in areas that weren’t, often at a faster rate. (8)”

And

“Globally, fluoridation is seen to make no difference to reduced decay rates, there being no difference between the few countries which use artificial fluoridation, and those that don’t. (8,7)”

His only evidence for this is a figure prepared by Chris Neurath from the Fluoride Action Network – using data from the World Health Organisation (WHO). Here it is in a slightly simpler version to the one used by Stan.

I am amazed that anti-fluoride propagandists keep using this graphic as “proof” that fluoride is ineffective. But they do – which can only mean they haven’t thought it through.

While the plots do show improvements in oral health for countries independent of fluoridation they say nothing about the effect of fluoride. Simple comparison of countries obscures all sorts of effects such as differences in culture, history, social and political policies, etc. Such plots are also influenced by changes and differences in dental treatment and measurement techniques.

Robyn Whyman in his report Does delayed tooth eruption negate the effect of water fluoridation? exposes the little trick Stan is trying to pull with the WHO data:

“Studies that appropriately compare the effectiveness of water fluoridation do not compare poorly controlled inter-country population samples. They generally compare age, sex, and where possible ethnicity matched groups from similar areas. Inter-country comparisons of health status, including oral health status, are notoriously difficult to interpret for cause and effect, because there are so many environmental, social and contextual differences that need to be considered.”

There are some within country data within the WHO data set Neurath used which can give a better idea of the beneficial effects of fluoridation. This plot shows the results for the WHO data for Ireland. A clear sign that fluoridation plays a beneficial role.

Neurath covered up evidence for the benefits of CWF by simply using the mean of fluoridated and unfluoridated areas for countries like Ireland and New Zealand. Also, the straight lines in Chris Neurath’s plots are a real give away to the poor quality of the data used. Two data points for each country!

New Zealand – Cherry-picking the MoH data

I have criticised Stan’s misrepresentation the Ministry of Health (MoH) data before. At the time he was using and misrepresenting some of my own graphics on his business website. He has since removed the offending article but now he returns with a vengeance – with tables and figures of his own.

This has given him free hand to cherry-pick and misrepresent to his heart’s content.

He claims:

“Ministry of Health figures recorded every year in 5 year olds and year 8s (12-13 year olds) consistently show minimal or no differences between fluoridated and nonfluoridated areas of NZ.”

stan_1

Cherry-picked data from Stan Litras

And he backs this up with a graph.

That looks about right. The data for 2011 shows 59.9% of 5 year olds in fluoridated areas were caries-free while 59.2% were carries free in non-fluoridated areas. No real difference.

But come on! A single data point, one year, one of the age groups for the fluoridated and unfluoridated areas! That is blatantly cherry-picking – as I mentioned in my article Cherry picking fluoridation data. In that I presented all the data for 5 year olds and year 8s, and for the total population and Maori, and for % caries free and decayed, missing and filled teeth (DMFT).

I have reproduced this data here in a simpler form using several figures.

caries-freeConsidering the % caries free data there are several points:

1: These do not “consistently show minimal or no differences between fluoridated and nonfluoridated areas” as Stan claims.

2. They do show a decline in differences between fluoridated and non-fluoridated areas in recent years.

3: This trend is less obvious for Maori but still present.

4: Stan has blatantly cherry-picked the  data points for 5 year-olds in 2011 to give him the least possible difference (see red circle in figure).

dmft

The data for decayed, missing and filled teeth (DMFT) shows similar trends.

Presumably both measures (% caries free and DMFT) are useful indicators of oral health but they probably convey complementary and not exactly the same information.

I discussed features of the graphs and their trends in in my articles Cherry picking fluoridation data and Fluoride debate: Response to Paul’s 5th article where I also discussed limitations in the data.

We need to appreciate this is just normal school clinic data, without technique standardisation for those making the measurements or proper recording of place of residence. The latter effect probably shows up more strongly after 2004 when a “hub and spoke” dental clinics system was introduced further confusing proper records of likely fluoride intake. One school dental clinic could serve a number of areas – both fluoridated and non-fluoridated. This mixing is a likely explanation for the apparent decline of the effectiveness of fluoridation after 2006.

So, yes, the MoH data is not straightforward. But this means it should be considered sensibly, taking into account its limitations and the social factors involved.  Instead, Stan has leapt in – found the data points which best fit his own biases and then tried to claim those data  are representative when they aren’t.

Stan presented another self-prepared graphic using data for the 4 different regions for 5 year olds (see his page 27). He appears not to have used the correct data – at least for the Northern and Southern regions.  My own graphic for this shows differences to his. (Of course, the mistake may be mine – if Stan can show I am wrong I will happily delete this part from my critique).

region-correct

Again, that data should also not just be considered at face value – or selected to confirm a bias. It has limitations. For example in this case there were only 55 children in the fluoridated Southern region compared with 7568 in the non-fluoridated area. A footnote on the data sheet says:

“2. Excludes Southern DHB because data were not reported for 1 Jan-20 Feb 2012, and fluoridation status was not captured for most children throughout 2012, due to transition to a new data system. “

Proper consideration of such data must take these sort of limitations into account. But of course all Stan Litras did was select data to support his assertions and ignore the rest. Any limitations in the data did not concern him.

Lifetime benefit

Stan has a thing about the “lifetime benefits,” or lack of benefits, of CWF. Most studies of CWF have used data for children – data for adults is less common but there is still research literature on this available.

But all Stan did on this was to cherry-pick a graphic (Figure 53) from the NZ Oral Health Survey showing no significant change in DMFT for 65-74 year olds between the years 1976, 1988 and 2009. He then claims:

“Data from the NZOHS 2010 do not support statements of a lifetime benefit, indicating that the action of fluoride is simply to delay the decay. (13)”

But he has had to work hard to avoid other data like that in Figure 49 below which do show a significant improvement in the number of retained teeth of that age group. The Oral Health Survey report itself says:

“In dentate adults aged 65–74 years, the mean number fell from 17.1 to 12.1 missing teeth per person on average from 1976 to 2009.”

mising-teeth

Again, instead of cherry-picking, searching for an image to fit his story, Stan should have considered the data and figures critically and intelligently. Perhaps the DMFT data does not show what he claims because more teeth have been retained in recent years. The decline in missing teeth could have been balanced by increases in fillings due to increase in remaining teeth. The lack of a significant difference in DMFT actually suggests the opposite to what he claims.

Litras also misrepresent the York review on the question of benefits from CWF for adults. He says:

“The York Review found there was no weight of evidence to support benefit in adults or in low SES groups, or increase of decay in cessation studies. (7)”

Just not true. The York report says:

“One study (Pot, 1974) found the proportion of adults with false teeth to be statistically significantly greater in the control (low-fluoride) area compared with the fluoridated area.”

Sheiham and James (2014) stressed that a proper assessment of oral health problems should include data for adults as well as children. Recent research is starting to take up this issue. For example O′Sullivan and O′Connell (2014) recently showed that water fluoridation provides a net health gain for older Irish adults.

Systemic vs topical

Stan promotes the common mythology of the anti-fluoridation propagandist that any mechanism for a beneficial effect of fluoride in restricting tooth decay is purely “topical.” He claims:

“It has been widely accepted since the 1990s that any effect on tooth decay from swallowing fluoride is insignificant or non-existent. To quote: CDC 1999: “the effect of Fluoride is topical “ (5); J Featherstone 1999: “the systemic effect is, unfortunately, insignificant” (6).”

Let’s consider what the sources Stan cites actually do say. I will quote from the 2001 edition of Stan’s citation 5 which he (partly) cites on page 36:

“Fluoride works to control early dental caries in several ways. Fluoride concentrated in plaque and saliva inhibits the demineralization of sound enamel and enhances the remineralization (i.e., recovery) of demineralized enamel (12,13 ). As cariogenic bacteria metabolize carbohydrates and produce acid, fluoride is released from dental plaque in response to lowered pH at the tooth-plaque interface (14 ). The released fluoride and the fluoride present in saliva are then taken up, along with calcium and phosphate, by demineralized enamel to establish an improved enamel crystal structure. This improved
structure is more acid resistant and contains more fluoride and less carbonate (12,15–19 ) (Figure 1). Fluoride is more readily taken up by demineralized enamel than by sound enamel (20 ). Cycles of demineralization and remineralization continue throughout the lifetime of the tooth.”

topical-mechanism

And

“Saliva is a major carrier of topical fluoride. The concentration of fluoride in ductal saliva, as it is secreted from salivary glands, is low — approximately 0.016 parts per million (ppm) in areas where drinking water is fluoridated and 0.006 ppm in nonfluoridated areas (27 ). This concentration of fluoride is not likely to affect cariogenic activity. However, drinking fluoridated water, brushing with fluoride toothpaste, or using other fluoride dental products can raise the concentration of fluoride in saliva present in the mouth 100-to 1,000-fold. The concentration returns to previous levels within 1–2 hours but, during this time, saliva serves as an important source of fluoride for concentration in plaque and for tooth remineralization (28 ).”

(Note: Stan simply quotes the first part of this statement (in red) in his article (page 36) and completely omits the second part (in black) – presumably because he wants to deny a role for fluoridated water in influencing the saliva fluoride concentrations. This cherry-picking of the CDC statement is typical for anti-fluoride propagandists – see Fluoridation – topical confusion).

There is an attempt to confuse a “topical” or “surface” mechanism with a “topical” application (eg toothpaste or dental treatments). However, fluoride is transferred to saliva from food and drink during ingestion so that ingested fluoride also contributes to the “topical” or “surface” mechanism.

However Stan wants to deny a “topical” role for ingested fluoride and claims (page 36):

“The required elevation of baseline levels only occurs after using fluoridated toothpaste or mouth rinse, a concentration of 1,000 ppm or more instead of 1 ppm from water.(24)”

His citation 24 is to Bruun (1984) and he misrepresents that paper which actually said:

“It was concluded that direct contact of the oral cavity with F in the drinking water is the most likely source of the elevated whole saliva fluoride and that the increased availability of fluoride in the oral fluids has an important relationship to the reduced caries progression observed in fluoridated areas.”

Systemic role.

Featherstone does say:

“Fluoride works primarily via topical mechanisms which include (1) inhibition of demineralization at the crystal surfaces inside the tooth, (2) enhancement of remineralization at the crystal surfaces (the resulting remineralized layer is very resistant to acid attack), and (3) inhibition of bacterial enzymes. Fluoride in drinking water and in fluoride-containing products reduces tooth decay via these mechanisms. Low but slightly elevated levels of fluoride in saliva and plaque provided from these sources help prevent and reverse caries by inhibiting demineralization and enhancing remineralization. The level of fluoride incorporated into dental mineral by systemic ingestion is insufficient to play a significant role in caries prevention. The effect of systemically ingested fluoride on caries is minimal.”

There is some debate over the role of systemic fluoride exuded by salivary glands. Many feel the concentration is too low – but because its effect is also determined by the presence of calcium, phosphate, organic species and pH it is best not to be dogmatic about this. It is, anyway, difficult to separate salivary fluoride derived from transfer from food and beverage in the oral cavity from that exuded by the salivary glands from systemic sources.

Stan is determined to deny a role for systemic fluoride during tooth development asserting:

“the erroneous theory that fluoride incorporated into children’s developing tooth enamel would make teeth more resistant to decay.”

While often neglected because of the concentration on surface mechanisms with existing teeth the theory that fluoride is incorporated into the developing teeth of children and confers a degree of protection is far from erroneous.

Newbrun (2004), for example, stressed in a review of the systemic role of fluoride and fluoridation on oral health:

“The role of systemic fluoride in caries prevention is neither “minimal” nor “of borderline significance.” On the contrary, it is a major factor in preventing pit and fissure caries, the most common site of tooth decay. Maximal caries-preventive effects of water fluoridation are achieved by exposure to optimal fluoride levels both pre- and posteruptively.”

Cho et al (2014) presented data showing that children exposed to CWF during teeth development retained an advantage over those never exposed to it even after fluoridation ceased.

Let’s stop confusing the issue. Systemic fluoride may not play a role with existing teeth but it does during tooth development – even if the relative contributions of systemic fluoride and “topical” or surface fluoride to lasting oral health are difficult to determine.

Tooth eruption delays

Stan resorts to special pleading when he claims with reference to NZ MoH data:

“Small apparent differences could be accounted for by other factors such as delayed eruption of teeth in fluoridated communities, therefore less time in the mouth exposed to plaque acids, ethnic distribution and urban/rural differences.”

He relies on the “York review” (McDonagh et al., 2000) to back up his “delayed tooth eruption” excuse:

“Importantly, the York Review noted that the variation of tooth eruption times between fluoridated and unfluoridated areas was not taken into account. (7)”

But that review actually said on this subject:

“It has been suggested that fluoridation may delay the eruption of teeth and thus caries incidence could be delayed as teeth would be exposed to decay for a shorter period of time. Only one study compared the number of erupted teeth per child. The difference was very small and in opposite directions in the two age groups examined, however no measure of the statistical significance of these differences was provided. Only one of the studies attempted to control for confounding factors using multivariate analysis (Maupomé 2000).”

Robyn Whyman has gone into this claim in more detail in his report Does delayed tooth eruption negate the effect of water fluoridation?Here he critiques Paul Connett’s reliance on this excuse and concludes from his review of the literature:

“The studies and reports cited by Professor Connett to try and validate an argument for delayed tooth eruption either do not make the claims he suggests, or do not have direct relevance to trying to assess the issue. The claimed association is at odds with the published literature which indicates minimal variation in eruption time of permanent teeth by exposure to fluoride. A rational explanation exists for the minimal variations that have been reported based on the relationship between fluoride exposure, caries experience in the primary teeth and emergence timing for the permanent teeth.”

The “delayed tooth eruption” excuse is nothing more than special pleading and straw clutching.

Socio-economic factors

Stan again misrepresented the York review regarding socio-economic effects on oral health and the effectiveness of CWF when he claimed “there was no weight of evidence to support benefit in adults or in low SES groups.” The York review actually said:

“Studies should also consider changes in social class structure over time. Only one included study addressed the positive effects of fluoridation in the adult population. Assessment of the long-term benefits of water fluoridation is needed.”

And

“Within the UK there is a strong social gradient associated with the prevalence of dental caries. This is found both in adults and in children. Those who are more deprived have significantly greater levels of disease. There is also geographical variation with the northwest of England, Scotland and Northern Ireland most severely affected. (Pitts, 1998; Kelly, 2000)”

There have been a range of studies internationally showing that fluoridation can aid in reducing differences in oral health due to socio-economic effects. See for example Cho, et al., (2014).

What happens when fluoridation is stopped

Stan briefly refers to this issue, citing (as anti-fluoridation activists always do) Künzel and·Fischer (2000). I will simply refer him, and interested readers to my article What happens when fluoridation is stopped? This boils down to the need to read the scientific literature properly as usually the anti-fluoridation activists ignore the details referring to fluoride treatments and procedures which replaced CWF.

There are a number of other points mentioned briefly by Stan Litras which could be discussed but this article is already too long so I will leave that to the comments section.

Conclusions

Stan Litras has simply indulged in blatant cherry-picking of data, and misrepresentation of the literature, in his critique of the recent review Health Effects of Water Fluoridation: a Review of the Scientific Evidence produced by the Royal Society of NZ together with the Office of the Prime Minister’s Chief Science Advisor. Perhaps we shouldn’t expect better from a political activist in the anti-fluoride movement but he, and Fluoride Free NZ, attempt to present this, and other articles in the collection, as objective and scientifically credible. It is neither – such cherry-picking and misrepresentation violates any scientific ethics and needs to be exposed for what it is. The Fluoride Free NZ claimed “peer reviewers,” Bruce Spittle and Hardy Limeback, must share responsibility because, by their endorsement, they signal their approval of such behaviour.

Note

I offered Stan Litras a right of reply to this post, or even an ongoing exchange with him along the lines of my debate with Paul Connett. He replied:

“I look forward to your comments on my review, as a lay person, but I cannot engage in a serious dialogue with someone who is not a peer with the same level of knowledge as myself in the dental field. “

Hopefully this means he will at least comment here, take issue with me where he thinks I am wrong and correct me where I am mistaken. I also hope than Bruce Spittle and Hardy Limeback will also take advantage of their right to comment here.

References

Bruun, C., & Thylstrup, A. (1984). Fluoride in Whole Saliva and Dental Caries Experience in Areas with High or Low Concentrations of Fluoride in the Drinking Water. Caries Research, 18(5), 450–456.

Centers for Disease Control and Prevention. (2001). Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States (Vol. 50, p. 50).

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

Cho, H.-J., Lee, H.-S., Paik, D.-I., & Bae, K.-H. (2014). Association of dental caries with socioeconomic status in relation to different water fluoridation levels. Community Dentistry and Oral Epidemiology.

Fluoride Free New Zealand. (2014). Scientific and Critical Analysis of the 2014 New Zealand Fluoridation Report.

Künzel, W.;·Fischer, T. (2000). Caries Prevalence after Cessation of Water Fluoridation in La Salud, Cuba. Caries Res, 34, 20–25. Retrieved from http://www.karger.com/Article/Fulltext/16565

McDonagh, M., Whiting, P., Bradley, M., Cooper, J., Sutton, A., & Chestnutt, I. (2000). A Systematic Review of Public Water Fluoridation.

Ministry of Health. (2010). Our Oral Health Key findings of the 2009 New Zealand Oral Health Survey. Wellington, Ministry of Health.

Ministry of Health (2014) Age 5 and Year 8 oral health data from the Community Oral Health Service. http://www.health.govt.nz/nz-health-statistics/health-statistics-and-data-sets/oral-health-data-and-stats/age-5-and-year-8-oral-health-data-community-oral-health-service.

National Fluoridation Information Service (2011): Does Delayed Tooth
Eruption Negate The Effect of Water Fluoridation? National Fluoridation Information Service Advisory June 2011, Wellington, New Zealand.

O′Sullivan, V., & O′Connell, B. C. (2014). Water fluoridation, dentition status and bone health of older people in Ireland. Community Dentistry and Oral Epidemiology.

Sheiham, A., & James, W. P. T. (2014). A reappraisal of the quantitative relationship between sugar intake and dental caries: the need for new criteria for developing goals for sugar intake. BMC Public Health, 14(1), 863.

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Today’s fantasy, tomorrow’s possibility

If you haven’t watch it yet this video, Wanderers,  is a must. And it is well worth watching full screen. It’s a science-inspired short film imagining human exploration of our solar system.

The voice-over is very recognisable – Carl Sagan reading from Pale Blue Dot.

This is what Phil Plait said about the film:

“This is one of the most wondrous and moving paeans to space exploration I have ever seen. The words of Sagan are magnificent, of course. And the effects are stunning, photo-realistic, and very compelling.

But take a moment and let this sink in: Nearly every location depicted in this video is real. These aren’t just fanciful places made up in the head of a special-effects artist; those are worlds in our solar system that actually exist. And many were based on images taken through telescopes, or probes that have physically visited these distant locales.

Sunset on Mars. The weird ridge wrapped around Saturn’s moon Iapetus. The ice fields of Jupiter’s moon Europa. Even those cliff divers? Yup: That’s Uranus’ moon Miranda, with the highest cliffs known in the solar system.

Every time the scene changed in the video, my jaw dropped a little further and my brain soared to a new height. Nothing in there is impossible; no faster than light travel, no wormholes. Even the space elevator shown towering over Mars and the huge cylindrical rotating colony in space (did you notice the Red Sea in it?) are problems in engineering, not physics. We can build them.”

All this is fantasy today but realistically possible in the not too distant future.

Thanks to: This Is A Majestic Vision Of Humans Embracing Our Exotic Solar System.

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The farce of a “sciency” anti-fluoride report

F network

Click for a larger image

I came up with the image above after a quick glance at a “report” promoted by the local Fluoride Free groups and Paul Connett’s Fluoride Alert organisation. (Scientific and Critical Analysis of the 2014 New Zealand Fluoridation Report). It illustrates the incestuous network of authors and “peer reviewers” involved in producing the “report.” I have also illustrated connections of these people to a number of anti fluoride organisations and 2 publications.

The first column lists the authors in red, and their claimed peer reviewers in green. The third column lists the anti-fluoride organisations and several publications these people are connected to.

The middle column lists some other people who are also connected to these organisations and publications. I have already reviewed Kathleen Theissen’s article (see Peer review of an anti-fluoride “peer review”) and will get around to reviewing the other 2 articles (by H.S. Miclen and Stan Litras) later.

Meanwhile, lets just consider the connections between these authors, “peer reviewers” and anti-fluoride organisations.

Taking in each other’s laundry

Most of these names are familiar to anyone who has followed the anti-fluoride movement. That fact in itself shows how this report can in no way be seen as “expert,” “independent” or at all credible. Some details on the illustrated people, organisations and publications.

NRC Review minority: There were several disagreements on the 12 member panel which produce the 2006 NRC report “Fluoride in drinking water. A scientific review of EPA’s standards” because 3 members were anti-fluoride. They were Robert Issacson, Hardy Limeback and Kathleen Theissen. Hardy Limeback is involved in several anti-fluoride activist groups.

Kathleen Theissen appears not to be organisationally involved but regularly makes anti-fluoridation submissions when the issue is debated.

UPDATE: Steve Slott has reminded me of this example of Theissen’s lack of credibility as a peer reviewer of fluoridation-related papers:

“In July 2013, Douglas Main, that freelance reporter and bastion of “objectivity”, interviewed Thiessen to get her opinion on Hirzy’s study on which he based his petition to the EPA.

From the article:

“Experts not involved with Hirzy’s study agreed with its findings.”

“I think this is a reasonable study, and that they haven’t inflated anything,” said Kathleen Thiessen, a senior scientist at SENES Oak Ridge Inc., a health and environmental risk assessment company.”

When the EPA reviewers looked at Hirzy’s study they found that he had made a 70-fold miscalculation in his study. When corrected for that error, the EPA reviewers found that Hirzy’s data actually demonstrated the exact opposite of what he had concluded.

Seems Thiessen either didn’t bother to read Hirzy”s study prior to commenting on it, or she overlooked his glaring error, too.”

Fluoride/ISFR: The International Society for Fluoride Reasearch (ISFR) publishes the journal Fluoride and organises regular conferences. They provide an avenue for authors to publish anti-fluoride articles, and generally poor quality research from areas where endemic fluorosis is common which may not be acceptable in the normal scientific journal.

The Society is based in New Zealand and is registered here as a charity. Bruce Spittle is the treasurer and journal managing editor.

FTRC/Second look: The anti-fluoride organisation and web site Second Look as set up the Fluoride Toxicity Research Collaborative (FTRC). It appears to be a weak attempt to provide a front “scientific institute” for anti-fluoride activists who want to present themselves as scientific experts.

This reminds me of the creationist Biologic Institute set up by the intelligent design creationists at the Discovery Institute. Actually, the Intelligent Design “pretend” scientific journal Bio-complexity also reminds me of the anti-fluoride journal Fluoride.

The FTRC lists the following staff:

  • Russell Blaylock, M.D., FTRC Medical Director
  • Hardy Limeback, Ph.D., D.D.S, FTRC Principle Investigator
  • Phyllis J. Mullenix, PhD., FTRC Research Program Director
  • Aliss Terpstra, RNCP, FTRC Research Coordinator

So far they claim to have sponsored (financed?) 2 research papers only by Phyllis Mullinex. Have a read of them and make up your own mind about their quality.

Case Against Fluoride: This is Paul Connett’s book The Case against Fluoride: How Hazardous Waste Ended Up in Our Drinking Water and the Bad Science and Powerful Politics That Keep It There. It is usually treated as a holy scripture in the anti-fluoridation movement. His co-authors were H. S. Micklen and James Beck.

Connett is very proud of this book and relies on it to support his claim to be a “world expert” on fluoridation.

Fluorine in Medicine: This is the sole scientific paper that Paul Connett can claim authorship (actually co-authorship) to:

Strunecká, A. ., & Patočka, J.; Connett, P. (2004). Fluorine in medicine. Journal of Applied Biomedicine, 2, 141–150.

The senior author Anna Strunecká is also part of the anti-fluoride network illustrated above. I am personally very suspicious of the quality of the journal which published this paper – anti-fluoride people have a history of placing poor quality papers in suspect journals purely to attain some sort of scientific credibility. DonQuixoteJune2011

FIND: The Fluoride Information Network for Dentists is one of the local Fluoride Free’s astroturf organisations claiming about 8 members but only Stan Litras is active. Stan uses his FIND hat for his anti-fluoride press releases – such as the one promoting the “report” considered here.

NZ Tour of Don Quixote & Sancho Panza: Sorry, can’t help thinking of these two when the upcoming NZ tour of Paul Connett and Bill Hirzy is mentioned. They do seem to be charging local fluoridation windmills with meetings in Taupo and Auckland.

William Hirzy: He is Paul Connett’s wingman on the Don Quixote & Sancho Panza Tour. Unlike Paul’s sole co-authorship he actually has 2 published scientific papers related to fluoridation where he appears as senior author. (See Comparison of hydrofluorosilicic acid and pharmaceutical sodium fluoride as fluoridating agents—A cost–benefit analysis and Corrigendum to “Comparison of hydrofluorosilicic acid and pharmaceutical sodium fluoride as fluoridating agents—A cost–benefit analysis” [Environ. Sci. Policy 29 (2013) 81–86]“)

The “credibility” of his “expertise” on the subject is shown by the fact his second paper was necessary to correct the huge arithmetic mistake he made in the first paper!

Perhaps you can see why the Connett/Hirzy act brings Done Quixote and Sancho Panza to my mind.

Conclusion

The “report” is discredited even before addressing the arguments presented – simply because of the well-known anti-fluoride stance of all the authors and “peer-reviewers.” The diagrammatic network shows just how incestuous the “report” is. It is simply an attempt to put a “sciency” face on their political stand and their attack on the Royal Society Review.

As a scientific presentation it is a farce.

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Creationist ‘audits’ science museum

Imagine you are 10 years old and your crazy aunt is taking you out for a treat.

A crazy aunt can be fun. Problem is this aunt is also a creationist and she is taking you to the local natural history museum.

Well it never happened to me (not that I didn’t have a crazy aunt) but I imagine this is what it would be like.

The museum is the Chicago Field Museum of Natural History – looks great.

Thanks to: Christian Fundamentalist Goes To Science Museum To ‘Audit’ Its Liberal Bias, Makes Ass Of Self VIDEO.

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“Real” experts’ on climate change? Really?

The Heartland Institute has produced a new propaganda poster on climate change. Here it is:

heritage poster

And this is what they say about it:

This poster presents clear and undeniable evidence that the debate is not over. Looking out from this poster are 58 real experts on the causes and consequences of climate change. Each of them refutes the existence of a “consensus of scientists” on the size of the human impact on climate, or whether it merits immediate action. Many of these experts say the threat is grossly exaggerated, often to advance a political agenda.

So they have raked up 58 “experts” – and how do they define “real experts?

Apparently their criteria is that they have spoken at one of the Heartland Institute’s climate denial conferences!

Sure they claim of these “real experts:”

“They include current and former professors of climatology, geology, environmental science, physics, and economics at leading universities around the world.”

But I have had a quick glance at the poster and at least 30 of these “real experts” really don’t have training or qualification in a field connected with climate. They include:

  • Journalists like James Delingpole and Christopher Booker.
  • Climate denial activists like Barry Brill, Christopher Monkton, Steve Gorham, Tom Harris and Joanne Nova.
  • Right wing “think tank” executives and fellows like Robert J. Bradley Jr., E. Calvin Betsner, Dennis Avery,Ron Arnold, Paul Driessen, Myron Ebell, Indur Golklany,  David W. Greutzer, Marlo Lewis, Marita Noon and James, M. Taylor.
  • Politicians like Vaclav Klaus, George Christenen and Roger Helmer.

There are also a few meteorologists (mainly weather forecasters), astronauts and economists.

Followers of the climate change debate will also be familiar with the remaining few on these who do have academic qualifications in relevant fields – and maybe some publications. They are the usual contrarians and mavericks who seem to bast in the glory of the promotion they get from climate change deniers.

“Real expert” – come off it.

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Water fluoridation and dental fluorosis – debunking some myths

Dental fluorosis is really the only “negative” side effect of community water fluoridation (CWF). It occurs in non-fluoridated as well as fluoridated areas but is often a little more common in the fluoridated areas.

However, there is a lot of rubbish about dental fluorosis spouted by anti-fluoride propagandists. It is worth putting dental fluorosis into its proper context and debunking some of the misinformation they promote.

Here are some facts.

1: Diagnosis of dental fluorosis involves grading teeth into 6 levels:

  1. No dental fluorosis
  2. Questionable
  3. Very mild
  4. Mild
  5. Moderate
  6. Severe.

Here are some photos of the different grades

2: The moderate/severe grades are rare in areas considered for CWF and fluoridation does not increase prevalence of those grades of dental fluorosis. However, those more severe forms are more common in areas where dental fluorosis is endemic like parts of China, India and north Africa.

Dental and skeletal fluorosis is a real problem in these endemic areas, but it is not a problem in the areas where CWF is used.

The figure below contrasts data for prevalence of dental fluorosis in NZ and the USA where CWF is common with data for an area of endemic fluorosis in China.

DF-grades-graph

3: The first 4 grades (none – mild) are judged purely “cosmetic. In fact children and parents often judge the grades questionable – mild more highly than none. Research finds these milder forms of dental fluorosis often improve dental health related 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).

In contrast research shows that the moderate/severe grades of dental fluorosis have a negative impact on health-related quality of life(Chankanka et al., 2010; Do and Spencer, 2007; Chikte et al., 2001).

4: Anti-fluoride propagandists often lump all grades together – presenting dental fluorosis as always bad. It also enables them to produce high figures to inflate the apparent problem. That is deceptive.

5: Anti-fluoride propagandists often use data from countries like India and China where fluorosis is endemic in their arguments against CWF. The figure above shows this is also deceptive.

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Proving anecdotes are reliable

anecdotesHere’s one to go with Let’s rely on anecdotes instead!

Something I picked up on Facebook

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Declan Waugh pushes another anti-fluoride myth

DeclanWaugh_photo

Declan Waugh – Champion cherry-picker

Declan Waugh seems a bit of a late developer. He has only just got around  to finding those papers that anti-fluoride propagandists like to cite as evidence that oral health does not decline when community water fluoridation is stopped. Of course, he cherry-picks the appropriate papers and is then careful not to give the full evidence.

But he has whipped up a Letter to the Editor promoting his new “discovery” – and encourages his fans to use the same information for their own letters to the editor.

Here’s Waugh’s claim in his letter to the editor (which he encourages his fan’s to duplicate).

Dear Sir.

In recent decades in four seperate countries notably Finland, the Netherlands, Germany and Cuba dental health professionals warned of the grave dangers to public health from discontinuation of water fluoridation. Yet ironically peer reviewed published scientific research demonstrated that dental health significantly improved among children when fluoridation of water ended. Scientific evidence proved in every case that the views and opinions of profluoridationalists among dental health professionals were misguided and errorneous. So why are we still listening to them?

Yours sincerely

  • Seppa L, Karkkainen S, Hausen H. Caries frequency in permanent teeth before and after discontinuation of water fluoridation in Kuopio, Finland. Commuity Dent Oral Epidemiol 1998;26:256 – 262.
  • Seppa L, Karkkainen S, Hausen H. Caries trends 1992 – 1998 in two low-fluoride Finnish towns formerly with and without fluoridation. Caries Res 2000;346:462 – 468.
  • Künzel W, Fischer T. Caries prevalence after cessation of water fluoridation in La Salud, Cuba. Caries Res. 2000 Jan-Feb;341:20-5.
  • Künzel W, Fischer T, Lorenz R, Brühmann S. Decline of caries prevalence after the cessation of water fluoridation in the former East Germany. Community Dent Oral Epidemiol. 2000 Oct;285:382-9.
  • Kalsbeek H, Kwant GW, Groeneveld A, Dirks OB, van Eck AA, Theuns HM. Caries experience of 15-year-old children in The Netherlands after discontinuation of water fluoridation. Caries Res. 1993;273:201-5

What these papers really say

I refered to this little myth in my article What happens when fluoridation is stopped? and will briefly repeat the information these propagandists always omit here.

L. Seppä, S. Kärkkäinen, and H. Hausen,Caries Trends 1992–1998 in Two Low-Fluoride Finnish Towns Formerly with and without Fluoridation.” Caries Research 34, no. 6 (2000): 462–68. The abstract for this paper concluded:

“The fact that no increase in caries was found in Kuopio despite discontinuation of water fluoridation and decrease in preventive procedures suggests that not all of these measures were necessary for each child.”

The authors commented further on this research in Seppa et al (2002). They found their “longitudinal approach did not reveal a lower caries occurrence in the fluoridated than in the low-fluoride reference community.” But commented:

“The main reason for the modest effect of water fluoridation in Finnish circumstances is probably the widespread use of other measures for caries prevention. The children have been exposed to such intense efforts to increase tooth resistance that the effect of water fluoridation does not show up any more. The results must not be extrapolated to countries with less intensive preventive dental care.”

W. Künzel and T. Fischer,Caries Prevalence after Cessation of Water Fluoridation in La Salud, Cuba.  Caries Research 34, no. 1 (2000): 20–25. Again this study found no increase in caries after stopping fluoridation but the authors suggested why:

“A possible explanation for this unexpected finding and for the good oral health status of the children in La Salud is the effect of the school mouthrinsing programme, which has involved fortnightly mouthrinses with 0.2% NaF solutions (i.e. 15 times/year) since 1990.”

W. Künzel, T. Fischer, R. Lorenz, and S. Brühmann,Decline of caries prevalence after the cessation of water fluoridation in the former East Germany Community Dentistry and Oral Epidemiology 28, no. 5 (2000): 382–89. These authors found no increase of caries in two German cities after fluoridation of water was stopped. But again the authors suggest why:

“The causes for the changed caries trend were seen on the one hand in improvements in attitudes towards oral health behaviour and, on the other hand, to the broader availability and application of preventive measures (F-salt, F-toothpastes, fissure sealants etc.).”

Kalsbeek, H., Kwant, G. W., Groeneveld, A., Dirks, B., van Eck, A. A. M. J., & Theuns, H. M. (1993). “Caries Experience of 15-Year-Old Children in The Netherlands after Discontinuation of Water Fluoridation. Caries Research, 27(3), 201–205. Tooth decay continued to decline after discontinutation of fluoridation in both the areas previously not fluoridated and fluoridated. But the authors say:

“The question as to whether water fluoridation would have had an additional effect if it had been continued (presuming the application of existing preventive measures) cannot be answered, as there are no remaining communities with fluoridated water in The Netherlands.”

Tooth decay is complex because it involves several factors. Improvements in public health, especially dental health availability, and alternative fluoridation options have produced a general improvement irrespective of the availability of community water fluoridation (CWF). However, where comparisons are made between fluoridated and unfluoridated areas in the absence of other differences the benefits are seen.

Studies do show increase in tooth decay when fluoridation stopped

Of course there are other studies which Declan Waugh and his anti-fluoride mates will refuse to cite because they do not support their claims. In Fluoride debate: Ken Perrott’s closing response to Paul Connett? I discussed a paper which did show an increase in tooth decay –  Attwood and Blinkhorn (1991), Dental health in schoolchildren 5 years after water fluoridation ceased in South-west Scotland.”  They measured dmft and DMFT – decayed, missing and filled teeth in primary and permanent teeth respectively.

The figures below illustrate the data from this paper which compared changes in oral health of two Scottish towns  in both 1980 and 1988. One town, Annan, had never had fluoridated water while the other, Stranraer, had it until 1983. This enabled the effects of both cessation of fluoridation and the generally observed improvement in oral health due to other factors to be compared and considered. The graphics show the results for 5 year old and 10 year old children.

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

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

The plots indicate aspects of the complexity of these sort of studies. Because 2 neighbouring towns were compared it was possible to measure the decline in oral health after discontinuation of fluoridation against a background of the general improvement in oral health, even in a non-fluoridated situation.

The moral here is don’t accept at face value the claims made by anti-fluoridation propagandists – even if they, like Declan Waugh, carry a self-endorsement of “scientist and fluoride researcher.”

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