Tuesday, April 30, 2013



Since writing my first report over 12 months I have received correspondence from other academics including Prof Roger Masters that have also discussed fluorosilicates in drinking water. Chapter 3 of my 2012 report was devoted entirely to this subject.  Some people seem to have difficulty finding it but its there to read plain as day. Since writing this I have found additional references that have also been discussed in follow up reports and correspondence that are also available on my website.

Anyway one of the most interesting observations I received was from Professor Roger  Masters a well known and respected researcher and academic who's work is referenced widely.

Here is what Prof Masters had to say about the Finney et al. report of 2006 on the dissociation of Hexafluorosilicic acid in drinking water in general. Its worthy of serious examination and thats why i have posted it here, so that people may better understand what we are dealing with when we add toxicologically untested man made synthetic fluoride chemicals into our drinking water.

Professor Roger Masters
I strongly urge that, with regard to ANY statement about "fluoridation" (as if it is a SINGLE CHEMICAL PROCESS), emphasis be focused on the DIFFERENT CHEMICALS used for the purpose, and the toxicity of fluorosilicic acid and sodium silicofluoride  (which was officially recognized by the National Toxicology Program in the U.S Centers for Disease Control when, in 2002, they formally nominated these compounds for study on the grounds that their "TOXICOLOGY" (that is, their toxic effects on humans) is not fully known.  Approval of sodium fluoride (NaF) does NOT -- as a matter of strict law -- apply to  fluorosilicic acid (H2SiF6) and sodium silicofluoride (Na2SiF6).

In many ways, the MOST definitive statement on this scientific issue of "toxicology" (in terms of the precise chemical consequences of adding these compounds to water which is then ingested by humans) is the following article:

   W. A. Finney, E. Wilson, A.Callender, M. D. Morris, and L. W. Beck, "Reexamination of Hexafluorosilicate Hydrolysis by [19]NMR and pH Measurement," Environmental Science & Technology, 40 (2006) 2572-2577.   This article uses precise chemical tests to make the point that the increased blood lead levels found in children's blood where silicofluorides are in use was NOT from lead atoms within the silicofluoride molecule.   The results of treating water with silicofluorides that are documented in this article include primarily LOWER pH (greater acidity) and a challenge to the assumption that the silicofluorides "dissociate completely".  By complete dissociation, Finney et al use the following chemical formula for the equilibrium result of adding silicofluoride to water (items in brackets are superscripts; "aq" apparently means "aqueous"; "L" -- actually lower case, but in this font that looks like the number ONE == means "liquid"; below, the use of back-slash will be used to show subscripts, so H/2/0 means the familiar H20 where 2 is a subscript meaning two atoms of hydrogen for one of oxygen):

        H/2/SiF/6/[2-] (aq) + 4H/2/O[L]  <----> (bidirectional arrows)   6H[+]  +  6F[-]  + Si(OH/4/) (aq)       (equation 1a)or
             SiF/6/2-] (aq) + 4H/2/O[L]  <----> (bidirectional arrows)   4H[+]  +  6F[-]  + Si(OH/4/) (aq)          (equation 1b)

The second equation obviously provides a cover for sodium silicofluoride; either one means that both the hydrogen and fluoride in fluorosilicic acid (or presumably the sodium in sodium silicofluoride) are indeed totally "dissociated" from the siliocon atom, AND that the silicon remains bonded to 4 OH atoms -- which is to say, there is a residue (which in some cases has been called "silicic acid").    Later in the article, however, these equations are qualified in a way that has substantial implications:

   "Fluorosilicic acid is a very strong acid with a second acid dissociation constant, pK[a2], of -0.65.  Thus, except under very acidic conditions the dominant form in solution will be the hexafluorosilicate ion.  So the equilibrium reaction is generally considered to be of the form given in eq. 1b.  However, this equilibrium is further complicated by the weak acidity of hydrofluoric acid and by the oligomerization of silicic acid to discrete oligosilicates and coloidal silica."
   (THAT LAST SENTENCE IS THE MOST IMPORTANT STATEMENT IN THE LITERATURE.  IT INDICATES THAT THE H(+) AND F(-) ATOMS THAT SPLIT OFF FROM H2SIF6 APPARENTLY FORM "SILICIC ACID" (HF).  I've copied the Wikipedia entry for hydrofluoric acid (HF) below: it is rated as highly toxic according to the report of the European Union's chemical categorization, and in any event is highly corrosive, so that if any HF remains in water treated with fluorosilicic acid, this would automatically be a sign of highly toxic effects not found with sodium fluoride (NaF).  The fact that Equation 1b refers to SiF6[2-] -- not Na2SiF6, which is widely used instead of H2SiF6 -- is curious, but only because it implies that IF sodium silicofluoride differs in its effects on users, it would be due to the difference between NaF (sodium fluoride, not toxic in low amounts) and HF (highly corrosive and toxic).  Such differences are NOT found in our work, but that's because the big difference is the phrase "oligomerization of silicic acid to discrete oligosilicates and coloidal silica"

The word "oligosilicates" refers the chains linking several atoms of silicates -- that is, a chemical residue that is a structure larger than a single silicon atom.  "coloidal silica" refers to sheets or structures of silicon atoms.     From a toxicological point of view, such structures could easily have serious effects on brain cells, since neurons have "receptors"  for neurotransmitters which are segments of the cell membrane that can accommodate a specific neurotransmitter (such as dopamine or norepinephrine, to mention two neurotransmitter functions that some research shows has been reduced where water is treated with silicofluoride.   However, the main point here is that the oligomers may explain greater absorption of lead in the environment that's observed in the blood lead levels of children where silicofluorides are in use.  That is to say, the Finney et al. article provides a plausible hypothesis for some of our findings (such as higher children's blood lead, which we NEVER attributed to lead bonded to the SiF molecule, but rather to a biochemical effect of the silicate residues.

While Finney et al. don't want to think of "silicate oligomers" or "coloidal silicate" as "residues", this is no more than verbal hocus pocus (defining an "intermediate" as a compound of silica and another element).  Besides, Finney et al. admit one effect of water treatment with silicofluorides that should have been on the front page of the NEW YORK TIMES.    The authors summarize their research findings as follows:

"The dissociation of hexafluorosilicate has been reinvestigated due to recent suggestions that fluorosilicate intermediates may be present in appreciable concentrations in drinking water.   19F  NMR spectorscope has been said to search for intermediates in the hydrolysis of hexalfuorosilicate.  No intermediates were observable at 10/-5/  M concentrations under excess fluoride forcing conditions over the pH range of 3.5 - 5.  A single intermediate species, assigned as SiF/5/[-] or its hydrate, was detected below pH 3.5.  A moderate pH values of 4 and 5 silica oligomerization in the solutions studied made it difficult to directly determine the hexafluorosilicate equilibrium constant.  Under more acidic conditions the average pK/a/ , or negative log of the dissociation constant K/d/, determined by the [19]F NMR  measurements, was 30.6.  We also investigated the behavior of hexafluorosilicate in common biological buffer reagents including phosphate /citrate, veronal/HCl buffers, and Ringer's solution.  The buffer capacity of all of these systems was found to be insufficient to prevent acidic shifts in pH when hexafluorosilicate was added.   The pH change is sufficient explanation for the observed inhibition of acetylcholinesterase that was previously attributed to hexafluorosilicate hydrolysis intermediates."  Finney et al., p. 2572.

In short, greater acidity is an unquestioned consequence of adding either silicofluoride to public water supplies that does NOT occur when sodium fluoride is added.  That acidity can affect one's digestion and other physiological conditions ought to be evident to anyone who suffered from gastric acidity (for example, in situations where a product like Pepto Bismol was useful).  More important, Finney et al admit that this effect can have important biochemical effects, since their abstract ends" "The pH change is sufficient explanation for the observed inhibition of acetylcholinesterase that was previously attributed to hexafluorosilicate hydrolysis intermediates."    First of all, this sentence explicitly refers to Johannes Westendorf's thesis (now available in English under <http://www.dartmouth.edu/~rmasters>, since he was the only scientist who made the claim that a "residual species" after the incomplete dissociation of silicofluorides was probably responsible for acetylcholinesterase inhibition.    Whether or not "coloidal silicate" or "silicate oligomers" are considered the same as the Silicon atom in the H2SiF6 or Na2SiF6 molecule depends on one's definition of the word "species" in chemistry.  That is, does Westendorf's term "residual species" necessarily mean something in which an atom on silicon is bonded to an atom of another element?   Or could that "residual species" be merely "coloidal silicate" or "silicate oligomers" (that structures of silicon atoms capable of having a biological effect)?

Finney et al. explicit ACCEPT the latter outcome as a matter of their scientific conclusions -- and that outcome is of immense BEHAVIORAL importance for the safety of silicofluoride use in water treatment.    The question they never ask is: WHAT IS THE BIOCHEMICAL EFFECT AND CONSEQUENCE OF ACETYLCHOLINESTERASE INHIBITION?    This depends on the enzyme's function: acetylcholine (ACh) is a major "agonic" neurotransmitter -- that is, it is a neurotransmitter that has excitatory effect on body movement.    Acetylchoinesterase (AChE) is an enzyme that breaks down acetylcholine (ACh), a function that prevents accumulation excess quantities of the neurotransmitter linked with body activity.

There's an obvious conclusion that has not occurred to either critics or supporters of water fluoridation.   If ACh is like the ON switch for bodily motor behavior, and AChE is an OFF switch (to lower activity), then destroying the OFF switch means the ON switch is more active.
VOILA: finally there's an explanation for the emergence and higher frequency of the behavioral phenotypes described as ADHD ("ATTENTION DEFICIT HYPERACTIVITY DISORDER").

I suspect many readers of this email won't have gotten through all these details.   It's time to get scientific about this matter, however:  over 90% of fluoridated water in the U.S. uses UNTESTED and TOXIC compounds who are admitted to have biological effects, even by those proclaiming their safety (Finney et al being the only major scientific study of the precise chemical effects of dissolving SiF in water -- the process called "hydrolysis").   The effects, as we have shown, can all be traced to weaker behavioral inhibition.  Greater lead absorption is one reason for this effect: lead reduces the activity of dopamine, a neurotransmitter that's a key to learning because in some neural pathways it has INHIBITORY functions.   Finney et al., agree with Westendorf that SiF also acts as an AChE inhibitor -- another factor in poor inhibition and more hyperactivity.

Our peer-reviewed findings documented -- WITHOUT REFERENCE to AChE inhibition or other mechanisms involved -- the statistically significant "association" between SiF and:

               1) higher blood lead levels.
               2) higher rates of violent crime
               3) higher rates of arrests for driving under the influence of cocaine
               4) lower scores on standardized educational tests & higher rates of learning disabilities

Poor attentional control (especially in school settings) and weak behavioral self-control are common factors in the dysfunctions we've documented.  Note that PROPERTY CRIME did NOT have the same degree of association with SiF use that we found with VIOLENT CRIME. Could this be explained by the fact that to be successful, the thief has to PLAN what he's going to do (e.g., rob the house when the owners
are on vacation or at least at work?)

I'm hopeful that the recipients of this email will realize that in the U.S., our top priority should be getting SiF on the list of chemicals prohibited from routine commercial sale under the Toxic Substances Control Act (TSCA): "The Toxic Substances Control Act (15 U.S.C. 2601-1692) consists of Public Law 94-469 (Oct. 11, 1976; 90 Stat.2003 and the amendments made by subsequent enactments."   Under the law, this action can be taken by the Director of the Environmental Protection Agency when there is EVIDENCE that a chemical MAY BE harmful.   Look up the law -- or if you can't find it I'll send the file.


  1. Okay, as far as I can see, Prof Masters makes four core points about the dangers of fluorosilicic acid:

    1) The fluoride and hydrogen ions released from fluorosilicic acid form hydrogen fluoride.

    2) Fluorosilicic acid acidifies water it is added to.

    3) Silica dissociated from fluorosilicic acid could oligomerizes, and this oligomerized silica could be toxic.

    4) Fluorosilicic acid could inhibit acetylcholinesterase enzymes.

    Correct me if I've made any errors here, otherwise I'll continue onwards soonish.

  2. Alright, I'll begin. I assume as someone with a science background you're familiar with the next bit, but I'll go over it in case anyone else is reading.

    All water exists in a dynamic equilibrium. Hydronium (H3O+) and hydroxide (OH-) ions are constantly being produced and recombining with each other, leading to a constant low level of these species in any water sample.

    The reaction for this is fairly straightforward:

    2 H2O <=> OH- + H3O+

    This idea of an equilibrium reaction is not unique to water. Chemical reactions, in general, have dynamic equilibria - in other words, the forward and reverse reactions often occur at the same time, although usually not at the same rate. The final equilibrium ratio for the chemicals involved depends on the relative favourability of the forward versus the reverse reaction - when this equilibrium is achieved the volume of forward reactions equals the volume of reverse reactions and the overall levels of both remain constant.

    This has the interesting implication that the final relative ratio of inputs to outputs for a chemical reaction is independent of the initial ratio.

    To clarify, if you have a chemical reaction which occurs in aqueous solution:

    A + B <=> C

    Then regardless of whether you add A and B, or whether you add C, or some mixture of the two, the final ratio of (A + B) to C will be the same, determined by the equilibrium constant for that reaction.

    None of this is at all controversial and you can find it all in any first-year chemistry textbook (I hope I haven't mangled the concepts too much in my explanation, but I assume you're familiar with them anyway).

    However, this has severe implications for Prof Master's first point, that H+ and F- ions released by fluorosilicic acid will form low levels of hydrogen fluoride in solution.

    He is correct, of course, but he seemingly fails to realize that any fluoride ions in any aqueous solution will also do this:

    The reaction for the dissociation of HF is:

    HF + H2O <=> H3O+ + F-

    It should be clear that this is a reaction that will follow the rules of dynamic equilibrium above - in other words, the final concentration of HF in solution at a given pH will be the same regardless of what the source of fluoride ions is.

    Of course, this ignores the fact that acids such as fluorosilicic acid and hydrogen fluoride acidify the solution, and this change in pH will alter the equilibrium for the above reaction. However, as long as they are being added in very dilute amounts this is unlikely to alter the pH of the water to any significant degree, and so my above explanation remains valid.

    The above observation also pertains to point #2 above - Prof Masters is correct that adding fluorosilicic acid will acidify water; this should be obvious from the 'acid' in its name. However, bear in mind that in Ireland fluorosilicic acid is added to achieve 0.6-0.8ppm F- ions, which corresponds to a little over 0.2ppm H+ ions (because dissociation of fluorosilicic acid releases 6 F- ions but only two H+ ions).

    Long story short, this volume of H+ ions will not alter the acidity of the water to any great degree. Natural water supplies vary in pH from region to region, and this natural variation will be far larger than any effects on pH from water fluoridation. It seems disingenuous to suggest that very mild acidification of the water poses any real health risk.

    Phew, that'll do me for now. Let me know if you have any problems so far! I'm always happy to be corrected - truth is more important than winning, after all.

    1. Oh, just as an addendum - bear in mind that adjustment of the pH of water is very easy to do, and so it would be trivial to correct the change in pH caused by fluoridation by simply adding relatively small amounts of, say, NaOH or similar.

      I have no idea if this correction is performed during water fluoridation, or if the pH change is small enough that they simply don't bother, but it's certainly feasible either way.

  3. Hi Matthew, questions from an interested observer:

    1. What is your opinion on the rationale for water fluoridation? Since fluoride's anti-caries effects are topical and post-eruptive, is it still useful to ingest it? If so, why?

    2. How much fluoride do you ingest every day? What do you consider to be a safe daily dose for yourself, and why? What do you consider to be safe daily doses for an infant, a child with iodine deficiency, and a person in stage IV renal failure? Why?

    3. What is your understanding of fluoride's biological activity, at the tissue and cellular level?

    4. Have you read any of the primary research showing water fluoridation to be effective? If so, what do you think of the quality of this evidence? If you find it more persuasive than evidence of potential harms, why so?

    Thank you.