Anti-fluoridation study flawed – petition rejected

A recent research paper claiming a signficant cost/benefit advantage in banning the use of fluorosilicic acid as a fluoridating agent in public water treatment, and replacing it with sodium fluoride, has been found flawed. This was revealed as a result of the rejection by the US Environmental protection Agency (EPA) of a petition by the author


Dr William Hirzy testifies for an anti-fluoridation group

The original paper by Hirzy et al. (2013) is on-line – full details are Hirzy, J.W., Carton, R.J., Bonanni, C.D., Montanero, C.M., Nagle, M.F. (2013) Comparison of hydrofluorosilicic acid and pharmaceutical sodium fluoride as fluoridating agents—A cost–benefit analysis  J Environmental Science and Policy Volume 29, May 2013, Pages 81–86.

Briefly the authors had used data (arsenic (As) concentrations in a number of samples of fluorosilicic acid and sodium fluoride) and a model for the predicted incidence of cancers resulting from As contamination in water supplies. Their cost/benefit analysis claimed “the U.S. could save $1 billion to more than $5 billion/year” by using pharmaceutical grade sodium fluoride instead of fluorosilicic acid.

Consequently Hirzy petitioned the EPA to ban use of fluorosilicic acid, using his study as supporting evidence. The EPA responded officially on August 6 and, despite some of the legalese, their notice is worth reading for anyone interested in the fluoridation controversy.

A calculation error for arsenic

When I first read Hirzy’s paper I was concerned that the quoted values for As in the fluorosilicic acid samples he considered were higher than found in New Zealand. (As concentrations in local fluorosilicic acid for water treatment are about the same as for the pharmaceutical garde sodium fluoride he used). I wondered if his data was out of date, or he had used commercial grade samples and not water treatment samples. However, the EPA found a more basic fault – Hirzy’s calculations were wrong! They had “failed to convert their estimates of lifetime cancer risk to estimates of annual cancer risk for the purpose of calculating annual net benefits.” When corrected the cost benefit analysis favoured fluorosilicic acid “(-$81M/year to -$8M/year, respectively) rather than pharmaceutical grade NaF over HFSA:”

1. Arsenic. EPA evaluated the cost-benefit analysis submitted by the petitioners and determined that the petitioners miscalculated net benefits for pharmaceutical grade NaF compared to HFSA. Specifically, it appears that the petitioners failed to convert their estimates of lifetime cancer risk to estimates of annual cancer risk for the purpose of calculating annual net benefits. This error alone results in a 70-fold overestimation of the number of annual cancer cases due to arsenic. That is, for the analysis in which the petitioners evaluate arsenic concentrations of 0.078 parts per billion (ppb) due to HFSA and 0.00084 ppb due to pharmaceutical grade NaF, the estimated numbers of cancer cases, when corrected, decrease from 320 to 4.6 per year for HFSA and from 3.4 to 0.05 per year for pharmaceutical grade NaF (Refs. 2 and 9). Similarly, for the analysis in which the petitioners evaluate an arsenic concentration of 0.43 ppb due to HFSA and 0.00084 due to pharmaceutical grade NaF, the estimated numbers of cancer cases,  when 8 corrected, decrease from 1,800 to 25 per year for HFSA and from 3.4 to 0.05 per year for pharmaceutical grade NaF (Refs. 2 and 9). After making the correction (i.e., annualizing the lifetime cancer risk), and retaining all other assumptions of the petitioners analysis, the analysis actually indicates that the cost-benefit ratio is in favor of using HFSA over pharmaceutical grade NaF (-$81M/year to -$8M/year, respectively) rather than pharmaceutical grade NaF over HFSA (Ref. 9). As a result, the information submitted by petitioners does not support the petitioners’ claim that there are net benefits in switching from HFSA to pharmaceutical grade NaF. Given that the petition is based upon the premise that the benefits of using pharmaceutical grade NaF as a fluoridation agent significantly exceed the costs relative to the use of HFSA as a fluoridation agent, EPA concludes that petitioners have not set forth sufficient facts to establish that HFSA presents or will present an unreasonable risk of injury to health or the environment with respect to arsenic or that it is necessary to initiate a TSCA section 6(a) rulemaking to protect adequately against such risk.

Lead risk not proved

The EPA similarly found that Hirzy’s claim that fluorosilicic acid caused leaching of lead from pipes in the water supply system was similarly unproved”

2. Lead. Petitioners assert that HFSA contains lead but provided no data to support this assertion. Petitioners also assert that the use of HFSA in lead-containing water piping systems results in leaching of lead from lead-containing water piping systems into water (Ref. 5), and that when chloramine is used in conjunction with silicofluorides greatly enhanced leaching of lead into water occurs (Ref. 3). . . . .  Based on the available evidence, EPA cannot conclude that the use of HFSA, with or without the presence of chloramine, results in enhanced leaching of lead.

Radioactive contaminants

Again the EPA found that Hirzy’s claims about radionuclide contamination were not supported:

4. Radionuclides. Although the petitioners mention “concern” about radionuclides, the petitioners present limited information to support a claim that HFSA presents or will present and unreasonable risk with respect to radionuclides. NSF compiled data from initial and annual monitoring tests for fluoridation products that NSF certified to NSF/ANSI 60 between 2007 and 2011 (216 samples) and between 2000 and 2006 (245 samples). Alpha emitters (type of radioactive decay in which an atomic nucleus emits an alpha particle) were detected in less than 1% of the 216 samples analyzed between 2007 and 2011. The mean (non-detects were estimated at ½ the detection limit) and maximum values were less than the MCL of 15 picoCuries per liter (pCi/L) and were less than the NSF/ANSI 60 SPAC of 1.5 pCi/L (Ref. 15). Beta photon emitters (another type of radioactive decay in which an atomic nucleus emits a beta particle) also were detected in less than 1% of the 216 samples analyzed between 2007 and 2011. The mean (non-detects were estimated at ½ the detection limit) and maximum values were less than the MCL of 4 millirems per year (mrem/y) and were less than the NSF/ANSI 60 SPAC of 0.4 mrem/y (Ref. 15). Radionuclides (alpha or beta) were not detected in any (0%) of the 245 samples analyzed between 2000 and 2006 (Ref. 11). The concentrations reported represent contaminant levels expected when the fluoridation products are dosed into water at the allowable maximum use levels for NSF/ANSI 60- 2012 (see Refs. 14 and 15). NSF notes that lower product use levels would produce proportionately lower contaminant concentrations. Thus, the petition has failed to present facts that establish that HFSA presents or will present an unreasonable risk of injury to health or the environment with respect to radionuclides, or that it is necessary to issue a TSCA section 6 rulemaking to protect health and the environment from such risk.

So, it would be nice if anti-fluoridationists would stop using Hirzy’s paper to “prove” that use of fluorosilicic acid causes cancer when used as a fluoridating agent. Or better still, stop promoting the lie that such fluoridating agents contaminate our drinking water with toxic heavy metals and radioactive elements.

But, going by past practice I am not going to hold my breath.

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42 responses to “Anti-fluoridation study flawed – petition rejected

  1. It is illegal for a doctor or a dentist to force anyone to take a drug or a chemical. It should be illegal for the government as well.
    The public water supply should never have been used to deliver a drug. Once added to the water you cannot control the dose, you cannot control who gets the medicine, no doctor is checking side effects such as individual susceptibly, it is taken for life in every glass of water and it violates individual’s right to informed consent.

    Medical professionals should be ashamed to support such a crude and unethical practice which results in cancer, thyroid & pineal gland damage, broken hips from brittle bones, lowered IQ, kidney disease, arthritis and other serious health problems.
    See “Health Effects” at


  2. jwillie6, Fluoride Alert is a very unreliable source. If that is all you read no wonder you are so confused. Fluoride is not a drug – it’s a beneficial element.


  3. It is illegal for a doctor or a dentist to force anyone to take a drug or a chemical.

    What have you got against chemicals, jwillie6?
    You are just a bag of chemicals yourself, a bag of chemicals that relies on chemical reactions and daily ingestion of more chemicals in order to stay viable.


  4. Besides, no one’s forcing anyone to drink fluoridated water. However, if tap water in your area is fluoridated, it’s probably cheaper to drink it rather than going through the hassle of getting non-fluoridated water supplied to your house regularlyin bulk loads, if that’s even possible at all.


  5. Yes I think it is fair to say that drinking tap water is cheaper than buying bulk Evian.


  6. Mind you, Andy. In some countries it’s a cultural choice. Italians mostly drink bottled water – which is one reason Italy doesn’t bother fluoridating its public water supply. Another is the fact that for geological reasons some parts of Italy already have adequate levels of fluoride in their water.

    The primary role of bottled water with some people was one of the issues Armfield studied in Australia. His conclusion was that the lack of bottled water on the Australian market containing fluoride put these people at a disadvantage health wise.


  7. The French drink mostly bottled water too. Is this fluoridated? I presumed that mineral water was straight from the spring and had nothing additional put into it.

    Bottled water seems a little decadent and not very environmentally friendly (all those plastic bottles)

    Christchurch tap water used to be as good as spring water until the earthquake stuffed things up for them


  8. Some bottled water in the US is fluoridated. But in Europe I think there is a tendency to drink specific spring or other sourced water. Some of these can have relatively high levels of salts naturally (which is usually part of its “charm” – and in some case the F content would be adequate. I know the Belgiums, who have been establishing regulations for F in foods and drink, had a dilemma with bottle water. Where the F was too high they felt they couldn’t regulate to lower the F content because that would destroy the character of the drink.


  9. Do the Belgians actually establish regulations these days? I thought most of those get made by the EU (which happens to be Brussels, which is in Belgium, but I digress)


  10. Bottled water is I think generally not from a spring, except the more expensive sorts like Spa and Bar-le-Duc. On holiday in France the tap water seemed to us too “chalky” but the big bottles at the Lidl were completely fine, but that’s just anecdote.
    Bottled water is usually labled with whatever minerals it contains expressed as the total mass of the individual ions, usually sodium, potassium, calcium and magnesium as cations and chloride, sulfate, nitrate and bicarbonate (standing in for all forms of dissolved carbon dioxide) as anions. They might also list fluoride but I can’t say I’ve ever seen it though I’ve deffinitely seen nitrite listed.
    Yes, EU countries do still get to make regulations pretty much as long as international trade isn’t hurt. I think food doesn’t usually go very far, most labels are in Dutch with added French so they can be sold across Belgium aswell, but again that’s anecdote.


  11. In the Netherlands that is.


  12. I guess the main issue is that people don’t like you messing with their water, whatever the science says.


  13. I doubt that, Andy. We have a local problem with high levels of arsenic in our source water – do you think people are opposed to the “messing” which reduces that concentration to safe levels? Do you think they are opposed to the messing which removes contaminants and harmful bioata? Do you think they are opposed to the correction of the F deficiency? (Hint, the 2006 referendum and recent polling suggests not – we will know for sure in a few weeks because of our referendum).


  14. Ken

    From my experience most people are thick.
    They believe that putting things in water is poisoning them. They think that nuclear energy and fracking are bad things.

    They believe in dangerous or catastrophic global warming.

    They believe that genetically modified foods will turn tomatoes into killing machines.

    These kind of people vote for Green or Mana parties

    They are retarded and need to be treated as such


  15. Friday night sherry, is it, Andy?


  16. I don’t do Sherry.
    Just been watching too much of our glorious leader on Campbell Live.
    The God complex tends to rub off. “I am right and you are wrong”


  17. They believe in dangerous or catastrophic global warming.

    You can ignore NASA. You can stand in opposition to them.
    Yet if you’re going to do it then be honest about it.
    Say it loud and say it proud.

    It’s not “the Warmists”, Andy.
    It’s NASA.
    NASA and every single scientific community on the planet.

    It’s not “most people” or “they”.
    It’s NASA.

    Not eco-fascists.
    Not hard-left Marxists. Oh no.
    It’s NASA, Andy.
    NASA and every single scientific community on the planet.

    Do you know why you use pejoratives rather than….NASA?
    It’s because when you fight the good fight against something wispy and ill-defind like “Gorebots” or whatever, it sounds more or less reasonable.
    Nobody cares about Gorebots or is even sure what you are going on about. Sounds sinister, though.
    Not all that crazy.
    ‘Cause it’s just you versus those dirty commies or whatever.

    Creationists do the same thing.
    They don’t much weeping and wailing about biologists or scientists.
    They like to slyly avoid those particular words.
    They’re against those “evolutionists” or those “Darwinists’

    The anti-vaxxer nutters?
    Who are they fighting against?
    Is it the medical scientists? Nope. Heaven forbid!
    They’re fighting against “Big Pharma”.

    Science deniers use pejorative framing all the time.If they stuck to reality, then the spin would be that much harder.

    See for yourself…

    “From my experience NASA is thick.”
    “My only hope is that when NASA realises that the only way to draw attention to the “climate crisis ” that NASA and every single scientific community on the planet have created is to kill themselves (preferably in a very visible way using fire), then I might start to take interest.”

    It makes you sound batshit krazy.
    That’s why you can’t frame the conversation that way.
    You are forced to use different labels that you just make up yourself or borrow from some no-name blog you read.

    Don’t want to be labeled a science denier?
    Then stop following the standard patter that they always use.

    Me? I get to mention NASA and the CDC and the NIH and the CSIRO and The Lancet and the Journal Nature and Cell etc every blessed opportunity I get.
    It’s just so much fun. It’s so….sane and mundane and reasonable.
    NASA for breakfast, NASA for lunch and NASA for tea.

    You have a blog somewhere? That’s nice. Maybe that will work out for you someday.
    The rest of us will go with NASA.
    NASA and every single scientific community on the planet.

    It’s not you versus me.
    It’s you versus NASA.
    Good luck with that.

    NASA | From the Cockpit: The Best of IceBridge Arctic ’13


  18. I am interested to know which scientific papers outline that global warming will be dangerous or catastrophic.

    Can’t find it in the IPCC.cant find it at NASA

    Maybe I am thick


  19. This is a good example of the anti science activism.i allude to

    Golden Rice is GM fod, but it has the potential to save 680 000 lives a year through addressing vitamin A deficiency

    Yet Greenpeace are against it.


  20. Ask Greenpeace, Andy, if your query is serious.


  21. Actually I got the link from Bjorne Lomborg

    I don’t need to ask Greenpeace because I know the answer. They are an anti science, anti intellectual anti human Luddite socialist group whose only purpose is to make money for them selves and make everyone else’s life a misery in the process.


  22. If you know the answer Andy, why are you pretending not to by asking it here? It has nothing to do with the topic of the post.

    I get the impression you are a frustrated troll who has run out of places to comment (what as end to Treadgold’s blog – he provided a community fir you, didn’t he?).

    Why not you start up your own blog – try to get your own immunity going. Cummings might join you.


  23. You are correct that it is not directly related to the post.
    So why does Cedric provide us with the usual screed about NASA?
    Are NASA involved in fluoridation?

    Are there plans to fluoridate Mars?


  24. I’d like to get my own immunity going.
    What do you recommend? Vaccinations? Will Cummings join me?


  25. Can’t find it in the IPCC.cant find it at NASA
    Maybe I am thick.

    NASA isn’t thick.
    They have a website. You should read it and find out what they do say as opposed to what they don’t.
    If you find something about climate change on their site that you dispute then by all means, share.
    Tell us where NASA and the rest of the scientific communities have got it wrong.
    That would be good for a laugh.

    Yet Greenpeace are against it. Why?

    Maybe because they are doing what you are doing?

    Actually I got the link from Bjorne Lomborg

    Yep. Predictable. Why just meekly believe one guy that tells you what you want to hear? Is it because….he wrote a glossly book or is it because he has a blog? Dumb.

    I don’t get my science information that way.
    Individuals don’t interest me. I never name-drop. Don’t need to.
    I’ve got NASA in my corner. NASA and every single scientific community on the planet.

    I get the impression you are a frustrated troll….

    In spades. All he can do is buzz around and lay his little eggs.
    Meanwhile, the rest of us have NASA.
    Poor old Andy Scrase has nothing in comparison.
    Nothing but the frustration of a kook.

    NASA Temperature Data 1880 2011 World global climate change


  26. Opponents allegation that most western countries do not fluoridate their water.” This statement is very misleading because:
    a) it suggests that water is the only large-scale vehicle for providing fluoride’s benefits to the public, and, therefore
    b) it creates the false impression that most western nations feel that fluoride is unsafe or unnecessary.
    If your news team had examined this topic closely, it would have learned that the opposite is true — fluoride is used by most of the large countries in the Western Hemisphere through various forms. These uses of fluoride are documented in a 2011 report by a German journal:
    • South America: Water, salt and/or milk fluoridation programs exist in all of the six largest countries in South America: Brazil, Colombia, Argentina, Venezuela, Peru and Chile. These nations account for more than 85% of the population on this continent. In Brazil alone, fluoridated water reaches more than 50 million people.
    • North America: On this continent, most inhabitants have access to fluoride, either from water or salt. All three countries (U.S., Canada and Mexico) have water fluoridation programs. Roughly 85 million of Mexico’s 112 million residents have access to fluoridated salt, which makes this the primary source of fluoride in the nation.
    • Western Europe: The largest nations in Western Europe have one or more forms of large-scale fluoridation programs to improve the dental health of their people. Britain, Spain and Ireland have water fluoridation programs. Germany, France, Poland, Switzerland and the Czech Republic use fluoridated salt. Most people in Germany (69%) and Switzerland (88%) benefit from this approach; roughly 60 million people in these two countries are reached through salt fluoridation. Some areas of Italy would have no reason to add fluoride because they have natural fluoride concentrations that are at the optimal level that has been shown to prevent decay. The bottled water culture of Italy has been identified as one barrier to water fluoridation.
    In the major countries of the Western Hemisphere, leading medical and health organizations endorse fluoridation through water and other means. For example:
    The Platform for Better Oral Health in Europe, a leading panel of experts, issued a 2012 report that recognized water fluoridation as a “good practice” for improving oral health. One of the policy recommendations in this report endorsed policies that will “ensure access to fluoride for the whole population.” In addition, this expert panel wrote that fluoridated water is “safe, cost-effective and has a demonstrable benefit.”
    The European Academy of Pediatric Dentistry stated in a 2009 article: “Water fluoridation is effective at reducing [decay] . . . It is socially equitable, in that it is available to all social groups and ages.” The Academy added, “The EAPD reaffirms its support for the use of water fluoridation as a community-based intervention to prevent dental caries.”
    The British Medical Association stated in 2010 that it “remains committed to the fluoridation of mains water supplies, after appropriate public consultation, on the grounds of effectiveness, safety and equity.”
    The Irish Forum on Fluoridation issued a 2002 report that concluded: “Water fluoridation has been very effective in improving the oral health of the Irish population, especially of children, but also of adults and the elderly.”
    The Canadian Public Health Association supports fluoridated water and issued a 2010 report that pointed out that fluoridation in Ontario province reaches a much larger share of the population than it does in Quebec province: “In Quebec, for instance, less than 7% of the population has access to fluoridated water. A study of the oral health of children between 1990 and 1999 found that kindergarten children in Quebec had 40% more cavities than children in Ontario and the United States, and that tooth decay affects 56% of Quebec children in Grade 2.”


  27. “If your news team had examined this topic closely …..”

    Time to fire your news team. They are clearly spending too much time on twitter and Facebook


  28. Are we neglecting you, Andy? Treadgold not satisfying your needs?


  29. No Ken!

    What are you insinuating?
    I find you impertinent
    What do you mean by ” not satisfying my needs”?

    How very dare you Ken. how Very Dare you!


  30. Pingback: Fluoride debate Part 1: Perrott | Open Parachute

  31. Pingback: Fluoride debate Part 1a – response: Connett | Open Parachute

  32. Pingback: Fluoride debate Part 1a – response to Connet’s response: Perrott | Open Parachute

  33. “Or better still, stop promoting the lie that such fluoridating agents contaminate our drinking water with toxic heavy metals and radioactive elements.” Are you joking??? Here is proof that HFSA is contaminated with arsenic and lead, obtained from my local water treatment facility in Peel Region, Ontario. Even Health Canada admits that ARSENIC CAUSES CANCER. (Note: the HFSA doesn’t even get tested for all the co-contaminants that is likely has. I advise others to contact their local facilities and ask for certificates of analysis for recent batches):


  34. Christine, the major source of arsenic in our drinking water is the source water. In our case (Hamilton, NZ) the source water actually has As concentrations about 3 times the maximum allowable level for drinking water and 80% oif it has to be revoved during treatment (see Hamilton – the water is the problem, not the fluoride!). Any As coming from treatment chemical is miniscule compared with that.

    Public water contaminants are set by relgulation. These set the maximium ocncentration of contaminants in treatment chemicals (coagulation chemicals are ususally more problematic than fluyoriudation chemncials) swo that concentrastiosn in the finished water are well below the maxumum permissible concentrations. The certificat you quote shows concentration I would expect tyo be weel below regulation maximums.

    However, I do notiuce that many Noreth American sourced samples of fluorosilicic acid are higher in contaminants than we experience in New Zealand. Perhaps we should start selling you our chemicals. 🙂

    This table shows Concentrations (ppm) of contaminants in several different batches of fluorosilicic acid from NZ and Australia. It is taken from my debate with Paul Connett.


  35. So the fact that arsenic occurs naturally is, in your opinion, justification to add more arsenic to people’s tap water (without the knowledge of some residents and against the will of others)?


  36. Ken, the EPA response says “This is a prepublication version of the
    action that EPA is submitting for publication in the Federal Register. While the Agency has taken steps to ensure the accuracy of this version of the action, it is not the official version of the final action for purposes of 15 U.S.C. 2620(b) Please refer to the official version of the document that will appear in a forthcoming Federal Register publication.” Hmmm. Is the official version ready yet? And could you please show how to get to the link you provided by clicking from the EPA’s website rather than going directly to the link? I tried to find my way from the EPA’s website to this link but was unable and would like to verify that this document is indeed posted by the EPA and in a manner that people might find it while browsing their site.


  37. P.S. I haven’t seen a retraction of the Hirzy paper.

    And who is Zilny? You say: “so, it would be nice if anti-fluoridationists would stop using Zilny’s paper to “prove” that use of fluorosilicic acid causes cancer when used as a fluoridating agent.” ???


  38. Christine, thanks for pointing out the typo – I have now corrected it.


  39. Can you please answer my other questions?


  40. Christine, I don’t think they warrant answers. You seem to be happy about contaminants in the source water and all the other treatment chemicals but want to rave on about the lower levels of contaminants in the fluoridation chemicals. That is not rational and regulating authorities must deal with real situations.

    As for links, surely you are capable of hunting them down yourself. Have a look at the fluoride debate articles. Bill Hirzy has included a comment in two of Paul Connett’s articles about his mistake and provides a reference to his correction there.



  41. My name is Christine and my questions are valid. The fact that there are already contaminants from other sources (which I am NOT happy about – please don’t put words in my mouth, I have not said anything remotely like that) doesn’t justify adding more. I’m not ranting – I’m concerned about having unnecessary toxins added to my tap water. I have lots of concerns about lots of things in life – this is just one of them and it’s the one we are supposed to be discussing here. Please stop changing the topic to source water and other treatment chemicals.

    So your answer is no, you won’t show me how to get to that ‘response’ from the EPA’s site. Interesting. And anyone could log in here under Hirzy’s name and post comments. Good grief, I could really be Carolyn for all you know.


  42. Christine, your objections on grounds of added contamination are complete and utter nonsense.

    Take the time to actually read Ken’s
    post and, even better, try to understand it. (Hint, think about what “orders of magnitude” implies.) Even the amount of natural variation of concentration in source water concentration of As in Hamilton’s supply would overwhelmingly swamp any adjustment due to fluoridation.

    If you cannot honestly grasp the numbers and concepts involved then consider that the levels of foreign contaminants in the water is regulated to well within safe levels, it is what ends up at the tap that is at issue, not where it comes from.


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