Silicofluoride Toxicity, Health and Behavior

[Roger.D.Masters@Dartmouth.EDU (Roger D. Masters) (by way of Keith Whyte <keith@tbmc.ie>)]

        

Professor Roger D. Masters
        Research Professor of Government
         &

Nelson A. Rockefeller Professor Emeritus
        President, Foundation for Neuroscience & Society
                310 Gerry Hall - HB 6222
        Office telephone: (603) 646-1029
        Office FAX: (603) 646-2153
        E-mail: Roger.D.Masters@Dartmouth.Edu

                                                September 17, 2002

Silicofluoride Toxicity, Health and Behavior

Although many discussions of water
fluoridation do not mention the specific chemicals used for this purpose,
our research has revealed highly important differences between compounds
now in use. "Fluoridation" began by adding sodium fluoride
(NaF), which is familiar in toothpaste and is the only water fluoridation
chemical that has been tested for safety. In the late 1940’s, Milwaukee
and a few other cities initiating fluoridation were told that stocks of
sodium fluoride were insufficient; as a result, fluorosilicic acid
(H2SiF6)
or sodium silicofluoride
(Na2SiF6)
were substituted for this purpose. In 1950, on the "assumption"
that silicofluorides dissociate completely (like sodium fluoride) and
would therefore be safe, the Public Health Service authorized their use.
As a result, over 90% of water fluoridation in the United States today
uses one of two chemicals that are still untested. We are therefore in a
paradoxical situation: while the Food and Drug Administration normally
does not permit the sale of untested pharmaceutical products, 140 million
Americans receive public water supplies treated with an untested toxin
for presumed medical benefit.
To understand the policy issue posed by this situation, four facts need
to be considered. First, silicofluorides are highly toxic compounds whose
addition to water supplies has never been tested for safety. Second, the
assumption on which their use was originally authorized (complete
dissociation after addition to water) has been contradicted by subsequent
laboratory studies. Third, epidemiological studies have found increased
uptake of lead from environmental sources (such as lead paint in old
housing) in communities using silicofluorides. Finally, controlling for
other risk factors, there are higher rates of violent crime, substance
abuse, and learning disabilities (all of which are behaviors associated
with lead neurotoxicity) in communities where silicofluorides are added
to water. On each point, evidence is persuasive.
FIRST, although proponents of water fluoridation rarely mention the
chemicals used for this purpose, a Center for Disease Control manual for
plant operators warns of "the hazard" of silicofluorides. In a
memorandum to the City Manager of Fort Collins, Colorado  which uses
silicofluorides  two water treatment managers ended a discussion of
"Operational Issues" by writing: "Finally, the chemical
used for fluoridation, hydrofluorosilicic acid, is very aggressive and
hazardous. As such, discontinuing its use would enhance the safety of our
employees." 
Unlike sodium fluoride,
however, the silicofluorides have never been tested for safety. As an EPA
official in Washington headquarters wrote me, "Health effects
research is primarily conducted by our National Health and Environmental
Effects Research Laboratory (NHEERL). We have contacted our colleagues at
NHEERL and they report that with the exception of some acute toxicity
data, they were unable to find any information on the effects of
silicofluorides on health and behavior." Another EPA toxicologist in
the Region 8 office wrote a local activist that : "I am not aware of
any toxicological testing on hydrofluorosalicic [sic]
acid."

Confirming these judgments, the National Toxicology Program (NTP) has recently nominated silicofluorides for study because there is a "lack of toxicity information" on these chemicals even though they are the "primary agents used to fluoridate public drinking water systems."
        SECOND, the NTP nomination just cited also indicates that the "assumed complete dissociation to free fluoride under normal conditions of use [is] not supported by experimental evidence." Laboratory research in Germany by Westendorf (1975) contradicted the assumption of "complete dissociation" which McClure had used in 1950 to justify approval of using silicofluorides. Westendorf also reported cholinesterase inhibition, an adverse biochemical effect from silicofluoride treated water that has not been reported for sodium fluoride

.
After Westendorf's study,
further research by Rastädter
revealed residual products of
incomplete dissociation (probably siloxanes and possibly low molecular
weight fluorine-bearing polysilicic acid oligomers) that are likely to be
stable and could account for enhanced uptake of lead. Hence the purported
functional similarity between the various chemical compounds used in
fluoridation cannot be maintained as scientifically accurate.
THIRD, our geographical analysis of children's blood samples in
Massachusetts, 
New York state, and NHANES III has found that children' s lead uptake is
significantly higher where either fluorosilicic acid
(H2SiF6)
or sodium silicofluoride
(Na2SiF6

) is in use than where water is treated with sodium fluoride, naturally fluoridated, or not fluoridated. In each of these three large samples (totaling over 400,000 children), our peer-reviewed scientific publications find silicofluorides are associated with significantly higher lead uptake from such environmental sources such as lead in water or lead from paint in old houses. Controlling for many other risk factors associated with lead toxicity, such as urban population density, race, and income, these effects remain statistically significant in the different samples. (Note that, contrary to a misinterpretation of these publications, we have never claimed that these effects are due to lead levels in the silicofluorides prior to their injection in the public water supplies.)
FOURTH, consistent with known neurotoxic effects of lead and their consequences for behavior, the geographical distribution of violent crime, substance abuse, and learning disabilities is significantly associated with the use of silicofluorides. For example, analyzing national county-level data for 1985 and 1991, after controlling for up to a dozen socio-economic and demographic risk factors, silicofluorides remain significant predictors of higher rates of violent crime. Recently released statistics by city for 2000 and 2001 confirm that where either fluorosilicic acid or sodium silicofluoride are used, rates of murder and rape were higher than where water is treated with sodium fluoride, naturally fluoridated, or not fluoridated.
Because sodium fluoride or naturally fluoridated water do not have the same effects as silicofluorides, fifty years of debates about "fluoridation" have been seriously flawed. To a large degree, neither critics nor supporters have addressed the chemical and biological characteristics of the specific compounds in use. Without prejudicing decisions on fluoridation with other chemicals, the facts summarized above justify a moratorium on the use of silicofluorides pending unbiased experimental studies of their toxicity and effects on health and behavior.
                        Prof. Roger D. Masters
                        Research Professor, Dartmouth College
                        Pres., Foundation for Neuroscience and Society

Notes