For those planning to submit my Op-ed piece to local
papers, here is a revised, and I hope strengthened
version.
The Relevance of the NRC Report
to Water Fluoridation
On March 22, 2006, a prestigious 12-member panel of the
National Research Council completed a three year review of
the appropriateness of the EPA's safe drinking water
standard for fluoride (officially called the Maximum
Contaminant Level Goal, or MCLG) which is currently set at
4 ppm. After one of the most thorough and objective
reviews of the literature in 60 years, the NRC panel
unanimously found that the MCLG is too high and has asked
EPA to lower the standard in order to protect children
against severe dental fluorosis and to protect all groups
from bone fracture. They have asked the EPA to perform a
risk assessment to determine what the standard should be.
Some have questioned the relevance of this action to water
fluoridation, since the panel was not invited to examine
the risks and benefits of artificial fluoridation, in
which fluoride is added to water at about 1 ppm ostensibly
to fight tooth decay. This column examines the findings
presented in the NRC's 450 page report and explains why
they are highly relevant and important to any
consideration of water fluoridation. Here are the relevant
concerns:
1) The disappearing "margin of
safety." The gap between the level at which
fluoride is added to water, ostensibly to protect teeth (1
ppm), is already very close to the level at which the EPA
requires fluoride to be removed (4 ppm). The recommended
lowering of MCLG will make this gap even smaller and thus
even more relevant to water fluoridation at 1 ppm.
2) Dose cannot be controlled.
This very small gap becomes even more
significant when one recognizes that while engineers can
usually control the level of fluoride added to water
(although there have been accidents), they cannot control
how much water people drink. Nor can they control the
fluoride that people get from other sources such as dental
products and treatments, processed foods and beverages,
fluorinated medications, pesticides, and air pollution.
3) Exposure analysis.
The NRC was charged with finding out how much fluoride
people are actually getting, considering the wide
variations in water consumption and other sources. The
MCLG of 4 ppm was derived from the "safe" dose of 8
milligrams per day on the assumption that the "average"
adult drinks 2 liters of water per day. Many people drink
far more water than this. Using the panel's exposure
analysis it can be readily shown that some people will
exceed a "safe" intake of fluoride (either expressed as a
dose of 8 milligrams per day for an adult, or a dosage of
0.114 mg/kilogram bodyweight per day when considering
infants, children and others with different bodyweights)
even at 1 ppm.
4) Adverse Effects at low
exposures. The extensive NRC report reviewed
many animal and human studies where adverse effects on a
variety of tissues and organs have been observed at
relatively low levels of exposure to fluoride. Many of the
effects were observed at lower water concentrations than 4
ppm, or lower doses than 8 mg per day or lower dosages
than 0.114 mg/kg/day. These included increased uptake of
aluminum into the brains of rats exposed to fluoride at 1
ppm; lowered IQ in children in Chinese studies at levels
of 2.5-4.0 ppm; increased hip fracture rates in the
elderly at levels between 1 and 4 ppm and lowered thyroid
function at dosages as low as 0.01 mg/kg/day. As water
intake is random and intake cannot be controlled, all of
these studies become relevant for water consumption at 1
ppm.
5) Bone fractures. Hip
fractures in the elderly were observed a) in Finland at
water levels at or greater than 1.5 ppm (Kurtio, 1999); b)
increasing in what appears a linear fashion between 1 ppm
and 4.3 ppm in China (Li et al., 2001) and c) bone
fractures were found to increase between 1.5 and 5.5 ppm
in Mexico (Alarcon-Herrera et al., 2001). While the panel
did not feel they had enough data to state exactly at what
level hip fractures would increase, it did describe both
the Kurtio and the Li studies as good studies. When the
EPA does its health risk assessment on this issue they
will have to take these studies into account. What the NRC
report did was to point out that 4 ppm is not
protective against bone fractures for a lifetime
exposure. It did not indicate what level is protective
against bone fractures for a lifetime exposure.
6) Thyroid function.
Even more serious is the discussion the NRC provided on
fluoride's impacts on the thyroid and the brain. For the
thyroid gland the NRC panel report effects at levels up to
10 times lower than the dosage associated with the 4 ppm
maximum level in water (0.114 mg/kg/day) and which are
exceeded by millions of American children and adults
drinking water at 1 ppm.
Based on these observations, it is not clear why the NRC
panel did not recommend a safe level of fluoride lower
than 1 ppm. Their failure to do so appears to hang on the
slenderest of threads: the chance that these findings on
thyroid function in the peer reviewed literature in
Europe, Russia, and China may not apply to people in the
US. We can always do with more research to confirm
findings like these but the lack of research on these
matters in the US should not leave us with any confidence
in this situation. It should be a matter of grave concern
that this research has not been done here, even though the
artificial fluoridation program has been going on now for
60 years and as early as 1940, researchers were writing
about fluoride's impact on the thyroid gland (DeEds, F.,
1940).
7) Huge data gaps. The
NRC panel makes many research recommendations which reveal
huge data gaps in basic research on fluoride's toxicity in
the US. What it didn't say, but I am prepared to do so, is
that the US Public Health Service's 56 year-old adherence
to the water fluoridation program has severely limited
meaningful research into fluoride's health effects. Most
of the research money has been spent on dental research
with little or no attention to other body tissues and
organ systems.
As the NRC panel's research recommendations indicate, no
significant efforts have been made in the US to track the
levels of fluoride in urine, plasma or bones of the
American people. Such basic baseline research is critical
if one wishes to seriously explore whether there is a
connection between fluoride exposure and health effects
reported in the literature such as hypothyroidism,
neurological effects, arthritis or other conditions
afflicting millions of people. In the US, we have been
flying blind on these matters. Hopefully, the NRC's review
will stimulate some serious research by independent
scientists (not those chosen to support the interests of
the fluoridation program) in the future.
8) Uncertainties. The
NRC panel has strongly recommended that the US EPA conduct
a health risk assessment in order to ascertain a new MCLG
which is protective of the American people -- and that
includes more vulnerable subsets of the population, such
as infants, the elderly, and those with diabeties, kidney
impairment or heart disease. Because the NRC report has
shown that the literature indicates very serious concerns
and uncertainties, when the EPA does an updated health
risk assessment on these endpoints, these uncertainties
alone should force a margin of safety which will produce a
new MCLG lower than the 1 ppm now used in water
fluoridation.
9) The lack of signficant benefit
from fluoridation not examined. The assumption
that all is well with water fluoriation because the NRC
panel didn't examine this practice is highly misleading.
Had the panel members been required to look at the
benefits they would have been shocked on how poor the
science is that supports this practice. According to the
UK York Review (2000) there is not one grade A study. They
might also have been surprised to find that most European
countries do not fluoridate their water but according to
WHO figures their children's teeth are just as good if not
better than ours. Moreover, the largest NIDR study of
tooth decay in the US could find very little difference in
the permanent teeth of children who had lived all their
lives in fluoridated compared to non-fluoridated
communities (Brunelle and Carlos, 1990). To this we can
add the fact that US cities which have been fluoridating
for years are reporting a dental crisis. This reflects the
fact that there is a much stronger relation between tooth
decay and standard of living than one can ever find with
ingested fluoride.
10) The fluoridating agents in
water fluoridation programs. Also as a
consequence of not reviewing the water fluoridation
program, the panel did not have to deal with the fact that
the chemicals used in water fluoridation are not the same
as the fluoride that occurs naturally in some water
supplies. The chemicals used are contaminated industrial
grade materials, which do not occur naturally, but are
obtained from the scrubbing liquor of the pollution
control devices of the phosphate fertilizer industry.
These contaminated silicon fluorides have received little
significant toxicological testing, on the flimsy grounds
that once diluted the silicon fluoride compounds will
completely dissociate into free fluoride ions and the
contaminants will all be below levels of concern, even
though some of them like arsenic and lead have an MCLG of
zero and thus should not be deliberately added to the
water supply.
Conclusion: On many
fronts, this important review from the National Academy of
Sciences is of the utmost relevance to water fluoridation.
There is such a small margin of safety between a small
benefit to teeth and a huge risk to health - and none for
some high water consumers - that it is time to halt this
practice forthwith. Calling for more research after it has
been halted is fine. But to do that research while we
continue to dose 162 million Americans daily without firm
knowledge of what levels will cause damage to health is
preposterous. It amounts to the largest experiment with
the public's health ever conducted. If nothing else it
violates the Nuremburg Code which strictly forbids human
experimentation without the informed consent of the
patient. The vast majority of individuals being exposed
have never given their consent, and, until now, very few
have been fully informed on the downside of overexposure
to fluoride.
Paul Connett, Ph.D.
Professor of Chemistry
St. Lawrence University
Canton, NY
Executive Director
Fluoride Action Network
Fan_bulletins@lists.fluoridealert.org
