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fluoridation (where did science communication go wrong?)

I'm currently reading through the background information prepared for Hamilton City councillors ahead of the meeting they had yesterday, at which they decided to end the fluoridation of Hamilton's water supply. Right now I'm beginning to think that those of us who are science educators & communicators have done something very wrong, because in the summary of 'views against' I see things like this (emphasis in the original):

A key sub-theme that emerged within this topic was the view that fluoride is a chemical or poison.

Yes, fluoride is a chemical. So are table salt & dihydrogen monoxide**. So often we see the term 'chemical' used in a pejorative sense, ignoring the fact that everything on the planet, ourselves included, is at some level a concatenation of chemicals. Incidentally, in the right - or should that be wrong? - quantities all are toxic: drinking too much water can be fatal. 

The source of fluoride used in water fluoridation is hydrofluorosilicic acid (HFA).  

Several submitters attached copies of the Material Safety Data Sheets.... which includes various warnings such as "Avoid contact with skin and eyes", "Repeated or prolonged exposure may result in fluorosis" and "Avoid contaminating waterways".

And indeed, there would be major risks in allowing concentrated HFA to come into contact with skin or eyes. But somewhere along the track people seem to have lost track of the fact that people drinking fluoridated water are not exposed to these risks, for the HFA is highly diluted upon being added to the water supply. As above, the dose makes the poison.

One of the papers submitted in support of dropping fluoridation is summarised here (it's sometimes referred to as the 'Harvard study'). The paper itself can be read at this link. It's a meta-analysis of data from China, "where fluoride generally occurs in drinking water as anatural contaminant". Reasonably large areas of China have groundwater with more than 1.5mg/L of naturally-occurring fluoride - above recommended levels. The study found that

children in high-fluoride areas had significantly lower IQ scores than those who lived in low-fluoride areas

and concluded that

[t]he results support the possibility of an adverse effect of high fluoride exposure on children's neurodevelopment.

While I'm sure that this was viewed as significant support for stopping fluoridation, there's something missing:the 'high-exposure' groups were receiving naturally-high levels of fluoride in their water, or were drinking water contaminated by industrial wastes. Levels of fluoride in these groups reached more than 30mg/L. The 'low' groups (also called the 'reference' groups in the study) were getting less than 1mg/L - the same levels found in treated drinking water in New Zealand.

In other words, this study does not demonstrate that the up-till-now-current levels of fluoride in our water represent a danger to children's intellectual development. (Did those citing it in support of removing fluoride from our water, actually read it?)

Science education: we can do better. Much better. 

** You can demonise most things if you try hard enough.

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8 Comments

I have been reading the same document, Alison. I also went through many of the submissions. They are mostly of the form "I support .." without supporting information.

So I guess now I should have a look at the videos of the oral presentations.

The decision is concerning as it [goes against] overwhelming support for fluoridation at the referendum, and with the Councils own surveys.

Can't help feeling that our mistake was to leave defense of the science to just a few health professionals.

Yes, I noticed the bit about the majority of submissions (& I'm only assuming they were mostly anti-, which is perhaps unfair) were of the 'form-letter' variety. All too easy to do that sort of submission instead of having to provide good evidence in support of a point of view.

And yes, I think we dropped the ball a bit. As I said to Darcy over at Sciblogs, we need scientists to be passionate communicators, & that's hard for most of as as we're trained/expected to be dispassionate about what we do (well, in an idealised world, anyway!). But a bit of passion goes a long way towards helping to engage with an audience in a way that simply 'giving information' will never do.

I was completely flabbergasted by this decision. When I heard they were considering it, I thought "ha, that'll never get through; they won't listen to the woo-meisters."

You & me both, sister.

Thank-you! This is a much more useful source of rebuttal than just banging my head against the wall as I have been doing every time someone wants to talk about the dangers of "fluoridated water"

Glad to be able to help :) There's quite a bit of other info in the comments (to the same post) over at Sciblogs (http://sciblogs.co.nz/bioblog/2013/06/06/fluoridation-where-did-science-communication-go-wrong/ ) and on other Scibloggers' posts on the same subject.

I'm most curious as to what effect fluoride has on G proteins, Dr Peter Scanlan and Dr Jane Beck both talked about G proteins and the effect that fluoride had on them. They cited studies, forgive me I'm on mobile so I cant reference them but they are on the council tribunal coverage in the summations. They also spoke of the accumulative effect of F on the body , in particular the Pineal gland. I'm suspicious of the media reaction to this whole topic, there must be some middle ground. These are local doctors and the lady that runs the Breamar cancer facility is reasonably respected, the press has quite literally ignored them. Any thought appreciated.

This is not my field of expertise, but having said that I've had a quick look at some of the literature.

A variety of 'G proteins' are involved in cellular signalling cascades, including the sequence of events that's involved in building - and breaking down/reshaping - bone, something that our bodies do all the time (http://www.ncbi.nlm.nih.gov/pubmed/9917518). The G proteins implicated in that sequence interact with fluoride ions - which may come from a range of environmental sources, not only fluoridated water - to form complexes that then trigger activity in various genes involved in bone deposition. However, while fluoride's a normal part of that process, acknowledged adverse effects at higher doses mean it's not a brilliant therapeutic agent for things like osteoporosis (& there's research going on in the field of 'fluoride mimics' as a result of this).

I guess part of the debate hinges on definitions of what constitutes a 'higher' dose of fluoride (& much of what I've seen presented in favour of dropping fluoridation has ignored the details around doses).

On the question of whether fluoride is implicated in bone fractures, this paper's often trotted out as evidence that it does: http://www.ncbi.nlm.nih.gov/pubmed/11341339 However, its data don't support that conclusion (nor is it a conclusion that the authors make). This from the abstract: "A U-shaped pattern was detected for the relationship between the prevalence of bone fracture and water fluoride level. The prevalence of overall bone fracture was lowest in the population of 1.00-1.06 ppm fluoride in drinking water, which was significantly lower (p or =4.32 and

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Recent Comments

  • Alison Campbell: This is not my field of expertise, but having said read more
  • jj: I'm most curious as to what effect fluoride has on read more
  • Alison Campbell: Glad to be able to help :) There's quite a read more
  • Claire: Thank-you! This is a much more useful source of rebuttal read more
  • Alison Campbell: You & me both, sister. read more
  • Renee : I was completely flabbergasted by this decision. When I heard read more
  • Alison Campbell: Yes, I noticed the bit about the majority of submissions read more
  • Ken: I have been reading the same document, Alison. I also read more