February 13, 2002

Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road
Atlanta, Georgia 30333

Dear Sirs,

"The mission of the Agency for Toxic Substances and Disease Registry (ATSDR),
as an agency of the U.S. Department of Health and Human Services,
is to serve the public by using the best science,
taking responsive public health actions, and providing trusted health information
to prevent harmful exposures and disease related to toxic substances."
- ASTDR WEBSITE

After reviewing the 2001 Draft Toxicological Profile for Fluorides, errors, omissions and misrepresentations of research work were noted in the first and subsequent chapters.

Since publication of the 1993 Toxicological Profile on Hydrogen Fluoride, Fluorides, and Fluorine, very substantive findings on the adverse health effects of a variety of fluorides and fluorinated substances have been published. These have been excluded from the new Draft, while disproportionate attention is given to the prophylactic effects of fluorides on teeth.

On page 2, the authors refer to "sodium fluoride" as being "often" used to fluoridate drinking water. On page 15, we read: "One of the principal uses for sodium fluoride is the fluoridation of public water for the prevention of dental caries." There are many similar statements throughout the Draft which mislead readers into believing that this chemical is the most common fluoridating agent. Not until page 60, paragraph 2, do the authors acknowledge (in passing?) ". . . hydrofluosilicic acid, so exposure to this chemical is included in some epidemiological studies".

Hydrofluosilicic acid (H₂SiF₆) is used to fluoridate about 90% of the fluoridation schemes in the US where populations exceed 10,000. The American Water Works Association states very clearly that sodium fluoride (NaF) is used in a very small number of water fluoridation schemes.

The only health-related epidemiological studies which directly address H₂SiF₆ were done by Masters, et al. These were primarily concerned with the effects that silicofluorides in drinking water have on the availability of lead.^(1)(2)(3). Why were these references not cited?

In his own 1931 review, McClure noted that previous experiments conducted in the 1920s by Taylor, et al showed that calcium fluorosilicate is more toxic to animals than sodium fluoride.⁽⁴⁾ Definitive experimental work on fluorosilicates was published by Kick, et al, in 1935⁽⁵⁾ (see Table). However, a later paper by McClure, et al in 1950, selectively used Kick's findings to promote the use of fluorosilicates for drinking water fluoridation.⁽⁶⁾

None of the early published experimental work on fluorosilicates is discussed or cited in the Draft Profile. Moreover, the McClure review, "Availability of Fluorine in Sodium Fluoride vs, Sodium Fluosilicate"; Public Health Reports Vol 65 No 37; 1175-86; 1950 has been omitted from the Draft.

The omission of such a vital body of science provokes the notion that the ASTDR might have sought to avoid addressing the adverse health effects created by exposures to fluorosilicates from any source.

Kick, et al 1935, pg. 61

Kick was an eminent early pioneer in animal nutrition. Although McClure referred to the above table in promoting the use of fluorosilicates for drinking water fluoridation, neither he, nor any subsequent scientists took proper account of the data presented.

The Table shows significant differences in absorption from ingestion of sodium fluorosilicates than from sodium and calcium fluorides.

In their extensive experiments, Kick et al demonstrated the bioavailability of F from the different fluoride salts. They found that:

• The retention of sodium fluoride was similar to that of sodium fluorosilicate.

• The amount of F absorbed from fluorosilicates was about twice the level as that from sodium fluoride.

• Urine levels of F in the sodium fluorosilicate groups were three times higher than those found in the sodium fluoride groups.

The initial Kick, et al, experiments were undertaken using pigs as test animals to determine the effects of fluorine in mineral supplements, primarily raw phosphate rock. When the phosphate rock was digested in stomach acid (a process similar to creating phosphoric acid), one of the products was H₂SiF₆. On autopsy, the scientists found that chronic, parenchymatous nephritis (kidney failure) had occurred in the pigs. They wrote:

• They were pale in color, contracted, and firm in texture, and their surfaces roughened by numerous nodules and depressions. The capsules were slightly thickened, and in some instances, firmly adherent to the surface. Occasionally, small cysts containing a clear or amber colored fluid protrudes above the surface, or were more deeply situated in, the kidney. One section of the cortex appeared reduced in width, and frequently the medulla contained a considerable amount of fat.

Microscopically the kidneys showed a nephritis with a varying degree of degeneration of the tubular epithelium and, as a terminal result, the replacement of many tubules and glomeruli with fibrous tissue. None of the animals in the sodium fluoride-fed lot exhibited this condition.⁽⁷⁾

Taylor GE, 1929 noted that calcium fluorosilicate caused more adverse health effects in dairy cows than sodium fluoride.⁽⁸⁾

These fundamental experimental findings by Kick, Taylor and their peers, were either missed - or concealed - by McClure. Later scientists, including the authors of the Draft Toxicological Profile for Fluorides, who referenced McClure in their own work also appear to have accepted McClure's own citations on trust alone.

These long-standing errors and omissions must be rectified in the new Toxicological Profile for Fluorides.

Aluminum fluoride:

Speciation of fluoroaluminum complexes in soil and water was briefly discussed in the Draft. However, a large body of science dealing with the effects of fluoroaluminum complexes on G-proteins, neurological effects, etc, (which can be located on Pubmed via the internet), were not addressed.

Fluoridation agents added to the drinking water can enhance leaching of aluminum from cookware (Literature review for the NIEHS, 2000).⁽⁹⁾

On Page 91, the Draft authors note Varner, et al, 1998. However, extremely important results regarding aluminum fluoride toxicity were omitted by the authors of the Draft Profile, who briefly addressed only the sodium fluoride aspect of the work. ⁽¹⁰⁾

The Varner team observed that the animals who drank the aluminum-fluoride-laced water developed sparse hair and abnormal, copper-colored underlying skin which is related to premature aging. Further autopsy results showed serious kidney abnormalities in animals that drank water containing both sodium fluoride and aluminum fluoride.

The Varner team wrote: "Striking parallels were seen between aluminum-induced alterations" in cerebral blood vessels that are associated with Alzheimer's disease and other forms of presenile dementia." They concluded that the alterations of the blood vessels may be a primary event, triggering neuro-degenerative diseases.

Describing themselves as "astounded," the researchers further stated: "Not only did the rats in the lowest dose groups die more often during the experiment, they looked poorly well before their deaths. Even the rats in the lowest dose group that managed to survive the 45 weeks looked to be in poor health."

The Draft authors did not acknowledge that these results were a replication of two earlier Varner, et al experiments addressing aluminum-fluoride toxicity.⁽¹¹⁾, ⁽¹²⁾

Following the three Varner, et al, aluminium fluoride studies conducted between 1991 and 1998 80% of the experimental rats died before the end of each of the experiments.

The Draft authors should have mentioned that the NIEHS joined with the EPA to request the National Toxicology Program to commission studies on aluminum complexes - and specifically fluoroaluminum complexes - in drinking water. (Federal Register: December 4, 2000 (Vol. 65, No. 233)] [Notices] [Pages 75727 - 75730].).

Other notable omissions

1. The Roholm 1937 data which is cited in all basic fluorine toxicology papers.⁽¹³⁾

2. The toxicology of fluorinated pesticides.

While the Draft briefly mentions the use of fluorinated pesticides, no reference is made of the toxicity/neurotoxicity of pesticides and other organic fluorides to which much of the population is daily exposed.

The authors failed to provide a list or source of information for fluorinated pesticides, fungicides and herbicides.

3. Fluorinated medicaments

Fluorinated medicaments are briefly mentioned, but there is no substantive discussion, nor a comprehensive list.

Conclusion

The authors of the Draft included some new data, but omitted very troubling findings contained in the early and more recent research.

Is the ASTDR prepared to honor its Mission Statement to the American public in the new Toxicological Profile on Fluorides "to serve the public by using the best science, taking responsive public health actions and providing trusted health information to prevent harmful exposures and disease related to toxic substances"?

Yours truly,

George C. Glasser,

Formerly of St Petersburg, Florida.

REFERENCES

1. Masters RD, Coplan MJ, Hone BT, Dykes JE, Association of silicofluoride treated water with elevated blood lead, Neurotoxicology. 2000 Dec;21(6):1091-100.

2. Masters RD, Coplan MJ, Water Treatment with Silicofluorides and Lead Toxicity, Intern. J. Environmental Studies 56, 435-449 (1999).

3. Masters, RD and Coplan, M. Brain Biochemistry and the Violence Epidemic, Nova Science Publishers, Inc, New York (1999).

4. McClure FJ, Mitchell HH (1931) The effect of calcium fluoride and phosphate rock on the calcium retention of young growing pigs, J Agric Res 42: 363-373.

5. Kick CH, et al, Fluorine in Animal Nutrition, Ohio Agricultural Experiment Station, Bulletin 558, Nov. 1935.

6. McClure FJ:, Availability of Fluorine in Sodium Fluoride vs, Sodium Fluosilicate, Public Health Reports, vol 65 No 37; 1175-86; 1950.

7. Kick CH, Bethke RM, Edgington BH, Effect of Fluorine on the Nutrition of Swine, with Special Reference to Bone and Tooth Composition, The Journal of Agricultural Research, Vol. 46 No. 11, January 1- June 15, 1933

8. Taylor GE, Effect of fluorine ration in cattle ration: Experimental evidence indicated fluorine content of raw rock phosphate is the detrimental factor, Mich. Agr. Expt. Station Qrt. Bulletin 11, 101 - 104, 1929.

9. Aluminum Compounds - Review of Toxicological Literature, Abridged Final Report Prepared for Scott Masten, Ph.D., National Institute of Environmental Health Sciences, Contract No. N01-ES-65402, Submitted by Bonnie L. Carson, M.S. Integrated Laboratory Systems, October 2000.

10. Varner JA, Jensen KF, Horvath W, Isaacson RL, Chronic administration of aluminum-fluoride or sodium-fluoride to rats in drinking water: alterations in neuronal and cerebrovascular integrity, Brain Res. 1998 Feb 16;784(1-2):284-98

11. Isaacson RL, Varner JA, Jensen KF, Toxin-induced blood vessel inclusions caused by the chronic administration of aluminum and sodium fluoride and their implications for dementia, Ann N Y Acad Sci. 1997 Oct 15;825:152-66.

12. Varner JA, Horvath WJ, Huie CW, Naslund HR, Isaacson RL, Chronic aluminum fluoride administration, I. Behavioral observations, Behav Neural Biol. 1994 May;61(3):233-41.

13. Roholm K [1937]. Fluorine intoxication: A clinical hygiene study with a review of the literature and some experimental investigations, London, England: H.K. Lewis & Co.