This is Ken Perrott’s response to Paul Connett’s first article – Fluoride debate Part 1: Connett.
Paul’s first article appears to be a general overview and not detailed consideration of the ten points he makes. I will be similarly brief in my response to each point. Paul may wish to go deeper into specific issues in later contributions and I will respond in more detail then.
The medical argument
Paul’s first 3 arguments rely on defining fluoridation as a medical treatment. This is a common anti-fluoridationist approach. I have no wish to argue about that definition as it is really just a matter of semantics. You could use a weak definition of “medicine” which can include practically anything in your diet the body uses and may tolerate over a wide range of intake without harm. Or a tighter definition implying a drug with some sort of marked effect in the body and requiring relatively careful control of intake. But whatever definition is used should be openly declared and applied consistently.
Opponents of fluoridation usually apply their definitions of “medicine” inconsistently and the argument becomes a classic bait and switch tactic. It uses a weak definition of “medicine” to capture fluoride and then switches to a tight definition to argue that use of fluoride requires rigid controls. This presents them with a number of problems because a weak definition of “medicine” must also include “natural” as well as “artificial” fluoride at natural levels in water a food. (A weak definition may also include many other elements – perhaps even water itself). There is no such thing as a “fluoride-free” water supply. If we exclude natural levels of fluoride (and most other elements) from our definition of “medicine” then why should we treat levels for artificially fluoridated water any differently?
Connett’s point 1: Why should we not be concerned about controlling the dose of natural levels of fluoride (or many of the other elements we consume) while only be concerned about the fluoride added as a “top up?” The are no differences between the “artificial” and “natural” fluoride anions in drinking water. In reality most elements like this have a sufficiently wide range of concentrations and intakes for efficacy that it is just ridiculous to treat them like powerful drugs which need accurate dosage.
Connett’s point 2: Similarly why make charges of indiscriminate intake only for artificially added F and not for natural levels of F and other elements? The small number of people, if any, who may have problems with fluoridation levels of F will also have the same problems with natural levels of F. Such people, if they real exist, will need individual responses to either natural or artificial levels of F and possibly other elements. These people will need individual responses whether their water supply is artificially fluoridated or not.
Connett’s point 3: Why demand “informed consent” for situations where natural levels of fluoride have been “topped up” and not require it for natural levels of fluoride – which in some situations may actually be higher than for fluoridated water supplies.
Is fluoride a nutrient?
Connett’s point 4: This also reduces to semantics – how should “nutrient” be defined? Paul restricts his definition only to elements involved in “biochemical processes” – a definition confidently excluding the role of F in bioapatites – bones and teeth. Yet bones and teeth are important to organisms – so the strengthening of bioapatites, and the reduction of their solubility, by incorporation of fluoride is important.
Perhaps we can agree that F is at least a beneficial element, even if we can’t reach agreement on the use of terms like “nutrient” and “essential.”
Biochemical processes and fluoride
Connet’s point 5: It is easy to cite literature references showing negative effects of fluoride but we should not ignore the conditions used. Most such studies refer to much higher concentrations than used in water fluoridation and this is also true for the review by Barbier et al, 2010 Connett cites.
Let’s not forget that community water fluoridation describes “topping up” fluoride concentrations to about 0.7 ppm F. Yet reviews of negative effects on biochemical process will quote studies which have used 50 ppm, 100 ppm or even greater concentration of F in drinking water. Opponents of fluoridation often seem completely oblivious of these huge differences in concentration when they present a long list of claims about the ill effects of fluoridation.
Another confusion readers often have with such reviews is the use of different units. The sensible reader must often apply a few conversion factors when checking the fluoride concentrations used in the reviewed studies. 1 mM = 19 ppm (or mg/L) for fluoride.
It is possible to find similar evidence of harmful effects of essential elements when present in high concentrations. Selenium is an example of such an essential element. This graph illustrates the situation for fluoride and is common to many elements.
Diagram from Ethan Seigel’s blog Starts with a Bang (see Weekend Diversion: Fluoridated Water: Science, Scams and Society).
I am not denying the usefulness of these studies of negative effects of fluoride. Researchers and policy makers should continuously assess research findings for their relevance to the fluoridation issue and guidelines used in regulations. But this assessment must be critical and intelligent – not simply a search to confirm biases.
Health authorities should not be swayed by populist naive interpretations of research.
Naturalistic fallacies
Connett’s point 6: Sure, organisms evolve to fit the parameters of their environment. But to say “it is more likely that nature knows more about what the baby needs than a bunch of dentists from Chicago or public health officials in Washington, DC” is really not a good way of deciding this issue. Do we really want to argue that the situations in which marine animals evolved are the best to aim for in a society which has undergone so much cultural and intellectual evolution? Are we to reject the idea that society should task experts to consider possible approaches for our future by the argument that “nature knows best” and give up all rights for humanity to improve its condition? Do we really think that the environment that ancestral species experienced millions of years ago are necessarily the best for us today?
Modern humans live in environments offering a range of natural dietary fluoride intakes. We know that very low or very high intakes present problems for our bones and teeth. We should not avoid the problems this presents by saying “nature knows best.”
The very low levels of F in breast milk may have more to do the with inorganic role of F in animal bodies than any wisdom that “nature” has.
Fluorosis
Proponents of fluoridation do acknowledge dental fluorosis in a negative, although minor, aspect of fluoridation.
Connett’s point 7: Opponents of fluoridation will often quote high values of the incidence of fluorosis which ignore the fact that much of it is “questionable” and/or “very mild.” These grades are really only cosmetic and usually can only be detected by a professional. Opponents may also hide the fact that the incidence of fluorosis for children living in fluoridated may often be the same as, or only slightly greater than, the incidence for children living in non-fluoridated areas.
The graphs below shows the situation reported for New Zealand in the 2009 New Zealand Oral health Survey (see Our Oral Health).
See Wikipedia for a brief description of Dean’s Fluorosis Index.
Health experts have generally concluded that the apparent rise in the incidence of fluorosis is caused by increases in other forms of fluoride intake, such as from eating toothpaste, and not from fluoridated water.
Fluorosis could well have been a normal feature of teeth and bones for a very long time. Remember many areas of the world are high in natural forms of fluoride and the body does not seem to have a process for fine regulation of blood and plasma fluoride concentrations. Perhaps we should consider very mild and questionable levels of fluoride as cosmetically perfectly acceptable. Considering the natural variation in fluoride intakes some people might argue that “nature knows best.”
Nature of fluoridating chemicals
Connett’s point 8: Anti-fluoridationists make wild claims about fluoridation chemicals. “They are industrial waste products, loaded with heavy metals and fluorosilicates are toxic and/or untested for toxicity!”
Claims of contamination with toxic elements are easily, and often, made but are never justified with any evidence. So lets look at the reality.
By-products that are used are not waste products – and surely we should aim for the efficient use of natural resources. The purchaser of any product will sensibly make sure it is suitable for their requirements – and these are rigidly defined for water treatment chemicals.
Suppliers are required to provide certificates of analysis and maximum values for contaminants in chemicals used for water treatment. Those regulations are determined from the maximum concentrations of contaminants allowed in the finished water for human consumption. Safety factors are also involved as well as allowance for contribution from other sources.
The table below contains analytical data for contaminants taken from certificate of analysis for the last batch of fluorosilicic acid used in the Hamilton, New Zealand, water treatment plant (see FSA column). I compare the data with the maximum allowed impurity levels of fluorosilicic acid defined in the regulations (Impurity limits column) and with an example of the contaminant concentrations in finished water (Drinking water column).
| Toxic Element | Impurity limits* | FSA** | Drinking water** |
| Sb (ppm) | 40 | <0.09 | – |
| As (ppm) | 132 | 0.4 | <0.002 |
| Cd (ppm) | 40 | 0.11 | <0.001 |
| Cr (ppm) | 660 | 0.8 | <0.001 |
| Hg (ppm) | 26 | < 0.05 | <0.001 |
| Ni (ppm) | 264 | < 1 | <0.001 |
| Pb (ppm) | 132 | 0.8 | <0.001 |
* Maximum acceptable contamination.
** From Certificate of Analysis
***For Gear Island Treatment Plant, Greater Wellington region.
There are several points to make.
1: These concentrations are extremely low, meaning that the final concentrations in the finished water are insignificant.
2: For comparison, column one provides the maximum permissible concentrations allowed for fluorosilicic acid used for water treatment ( NZ Water and Wastes Association Standard for “Water Treatment Grade” fluoride, 1997. ).
3: The NSF,which regularly monitors contaminants in water treatment chemicals says in this year’s NSF Fact sheet on fluoridation:
“In summary, the majority of fluoridation products as a class, based on NSF test results, do not contribute measurable amounts of arsenic, lead, other heavy metals, radionuclides, to the drinking water.”
And the NZ Waste Water Association’s report says:
“Commercially available hydrofluorosilicic acid, sodium fluoride and sodium silicofluoride are not known to contribute significant quantities of contaminants that adversely affect the potability of drinking water.”
Brown, Cornwall & McPhee, 2004 say in their review paper, Trace contaminants in water treatment chemicals: sources and fate:
“ Coagulant chemicals are the main source of trace metal contamination in water treatment.”
4: Some people seem to think that simply quoting concentration of contaminant species is proof of contamination – irrespective of the actual magnitudes. I have seen speakers flash up a slide listing heavy metal contents without bringing notice to the actual concentrations. That is silly. Our environment, no matter how “natural,” will always contain some amount of contaminant chemicals – it is the actual amount that is important – not that it can be, or is, measured.
Arsenic in community water supplies
Paul raises the problem of arsenic and this provides an opportunity to put the contaminants in fluorosilicic acid into context. The table shows that As levels are typically very low in fluorosilicic acid used for water treatment (0.4 ppm As). In my article “Hamilton – the water is the problem, not the fluoride! “ I show that in the local Hamilton, New Zealand, situation the source water from the Waikato River is the major source of As in the finished water – several orders of magnitude greater than for than from treatment chemicals.
Anti-fluoridationists often rely on a recent paper by Hirzy et al. (2013) for their claims about As in fluoroslicic acid and it’s effect on the incidence of cancer. Hirzy has since acknowledged errors in his calculations and described himself as embarrassed by them and his mistake about cancers. A petition to the EPA which used his data to argue against use of fluorosilicic acid in water treatment was rejected partly because of these errors (see Anti-fluoridation study flawed – petition rejected).
Fluoridation data around the world
Connett’s point 9: Yes, a few countries do not fluoridate their water community supplies for political reasons, but decisions against water fluoridation can depend on a range of factors including size and centrality of water treatment plants, widespread use of bottled water, naturally sufficient water fluoride concentrations, etc.
Paul refers to a plot used by Cheng et al (2007) – which is similar to this one:
This and similar plots are much beloved but anti-fluoridation propagandists. But while the plots do show improvements in oral health for countries irrespective 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.
However, there are some within country data within the WHO data set Cheng et al 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 has played a beneficial role.
Political and scientific arenas.
Connett’s point 10: The debates around fluoridation involve both scientific and political issues. Inevitably this leads to the separate issues being mixed. I find, for example, that attempts to discuss the ethical aspects always get diverted into differences in understanding of the science. For example the paper Ethics of Artificial Water Fluoridation in Australia by Niyi Awofeso is meant to be a description of the ethical issues. However, it assumes mistaken ideas about the science – that fluorosilicate species are present in fluoridated drinking water. Without the correct science it is so easy to end up with invalid ethics.
Appeal to authority is also a problem. Connett does this, for example, in his reference to Prof. James Summer, Nobel prize winner. Similarly wild claims are often made about Nobel prize winners and “top scientists” opposing community water fluoridation – these are really not valid arguments.
I feel that opponents of fluoridation commonly rely more on confirmation bias than critical and objective assessment when referring to the scientific literature.
There is also a reliance on conspiracy theories and poisoning of the well. We have seen personal attacks on scientists and health authorities in New Zealand when they have spoken up to defend the science. Childish name calling, accusations of being paid to make incorrect claims, charges of being “shills” for industry, etc. This is simply “playing the man and not the ball” and makes good faith discussion of the science impossible.
This even gets into peer-reviewed scientific literature. The authors of the paper Connett refers to, Cheng et al 2007, do this when they accused one side, that of health authorities, of “questionable objectivity.” Pots and kettles?
All of these problems are probably inevitable for an issue like this where political and ideological interests operate. But they are an anathema to proper scientific consideration.
Professor Gluckman, the NZ Prime Ministers Chief advisor on Science commented that fluoridation controversies were an example of science being a proxy for values/political issues. This leads to misrepresentation of the science, cherry picking of data, and relying on confirmation bias and google for literature searches. Ideology and values are the motivating factors but a caricature of science is used in the debate.
Good faith discussion of the scientific issue around fluoridation requires much more objectivity than is usually demonstrated by the opponents of fluoridation.
Anyone wanting to follow the debate and/or check back over previous articles in the debate can find the list of articles at Fluoride Debate.
See also:
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. This book tends to be used as scripture by anti-fluoridationists today so I thought I would look a bit more deeply into his claim.
Opponents of fluoridation usually use a raft of arguments – this sometimes make discussions difficult because it leads to 
Open Parachute 