1.
Dr. Hardy Limeback, BSc, PhD, DDS 
Associate Professor and Head, Preventive
Dentistry
124 Edward St., Toronto, Ontario, Canada M5G-1G6
Fax (416) 979-4936
Tel(416) 979-4929
E-mail: hardy.limeback@utoronto.ca
Leading Canadian Research
Scientist/DDS...Opposes
Fluoridation of Drinking Water:
"April, 2000
To whom it may concern:
Why I am now officially opposed to adding
fluoride to
drinking water.
Since April of 1999, I have publicly decried
the addition of fluoride, especially
hydrofluosilicic acid, to drinking water for the purpose of preventing tooth
decay. The
following summarize my reasons.
New evidence for lack of effectiveness of
fluoridation in modern times.
1. Modern studies (published in the 1980's
1990's) show dental decay rates are so
low in North America that the effects of water fluoridation cannot be
measured.
Because of the low prevalence of dental decay, water fluoridation studies
today must be
carefully conducted to correct for mobility of subjects between fluoridated
and
non-fluoridated areas, access to fluoride from other sources, the lack of
blinding and
problems with the `halo' effect. Even when very large sample sizes are used to
obtain
statistically significant results, the benefit of water fluoridation is not a
clinically relevant one (the number of tooth surfaces saved from dental decay
per person is less than one half).
Recent studies show that halting fluoridation will either result in only a
marginal increase in dental decay which cannot be detected or no increase in
dental decay at all.
2. The major reasons for the general decline
of tooth decay worldwide, both in
non-fluoridated and fluoridated areas, is the widespread use of fluoridated
toothpaste,
improved diets, and overall improved general and dental health (antibiotics,
preservatives,
hygiene etc).
3. There is now a better understanding of how
fluoride prevents dental decay. What little
benefit fluoridated water may still provide is derived primarily through
topical means (after
the teeth erupt and come in contact with fluorides in the oral cavity).
Fluoride does not need to be swallowed to be
effective. It is not an essential nutrient!
Nor should it be considered a desirable `supplement' for children living in
non-fluoridated areas. Fluoride ingestion delays tooth eruption and this may
account for
some of the differences seen in the past between fluoridated and
non-fluoridated areas (i.e. dental decay is simply postponed). No fluoridation
study has ever separated out the systemic effects of fluoride. Even if there
were a systemic benefit from ingestion of fluoride, it would be miniscule and
clinically irrelevant. The notion that systemic fluorides are needed in
non-fluoridated areas is an outdated one that should be abandoned altogether.
New evidence for potential serious harm from
long-term fluoride ingestion.
1. Hydrofluorosilicic acid is recovered from
the smokestack scrubbers during the
production of phosphate fertilizer and sold to most of the major cities in
North
America, which use this industrial grade source of fluoride to fluoridate
drinking
water, rather than the more expensive pharmaceutical grade sodium fluoride
salt.
Fluorosilicates have never been tested for safety in humans. Furthermore,
these
industrial-grade chemicals are contaminated with trace amounts of heavy metals
such as
lead, arsenic and radium that accumulate in humans. Increased lead levels have
been found in children living in fluoridated communities. Osteosarcoma (bone
cancer) has been shown to be associated with radium in the drinking water.
Long-term ingestion of these harmful elements should be avoided altogether.
2. Half of all ingested fluoride remains in
the skeletal system and accumulates with age.
Several recent epidemiological studies suggest that only a few years of
fluoride ingestion
from fluoridated water increases the risk for bone fracture. The relationship
between the
milder symptoms of bone fluorosis (joint pain and arthritic symptoms) and
fluoride
accumulation in humans has never been investigated. People unable to eliminate
fluoride
under normal conditions (kidney impairment) or people who ingest more than
average
amounts of water (athletes, diabetics) are more at risk to be affected by the
toxic effects of fluoride accumulation.
3. There is a dose-dependent relationship
between the prevalence/severity of dental
fluorosis and fluoride ingestion. When dental decay rates were high, a certain
amount of
dental fluorosis was considered an acceptable `trade off' of providing an
`optimum' dose of 1.0 ppm fluoride in the water. However, studies published in
the 1980's and 1990's have shown that dental fluorosis has increased
dramatically in North America.
Infants and toddlers are especially at risk
for dental fluorosis of the front teeth since it is
during the first 3 years of life that the permanent front teeth are the most
sensitive to the
effects of fluoride. Children fed formula made with fluoridated tap water are
at higher risk to develop dental fluorosis. A relatively small percentage of
the children affected with dental fluorosis have the more severe kind that
requires extensive restorative dental work to correct the damage. The
long-term effect of fluoride accumulation on dentin colour and biomechanics is
also unknown.
Generalized dental fluorosis of all the permanent teeth indicates that the
bone is a major
source of the excess fluoride. The effect of this excess amount of fluoride in
bone is unknown.
Whether stress bone fractures occur more often in children with dental
fluorosis has not been studied.
4. A lifetime of excessive fluoride ingestion
will undoubtedly have detrimental
effects on a number of biological systems in the body and it is illogical to
assume
that tooth enamel is the only tissue affected by low daily doses of fluoride
ingestion.
Fluoride activates G-protein and a number of
cascade reactions in the cell. At high
concentrations it is both mitogenic and genotoxic. Some published studies
point to
fluoride's interference with the reproductive system, the pineal gland and
thyroid
function. Fluoride is a proven carcinogen in humans exposed to high industrial
levels.
No study has yet been conducted to determine the level of fluoride that bone
cells are
exposed to when fluoride-rich bone is turned over. Thus, the issue of fluoride
causing bone cancer cannot be dismissed as being a non-issue since carefully
conducted animal and human cancer studies using the exact same chemicals added
to our drinking water have not been carried out.
The issue of mass medication of an unapproved
drug without the expressed informed consent of each individual must also be
addressed. The dose of fluoride cannot be controlled. Fluoride as a drug has
contaminated most processed foods and beverages throughout North America.
Individuals who are susceptible to fluoride's harmful effects cannot avoid
ingesting this drug.
This presents a medico-legal and ethical dilemma and sets water fluoridation
apart from
vaccination as a public health measure where doses and distribution can be
controlled. The rights of individuals to enjoy the freedom from involuntary
fluoride medication certainly outweigh the right of society to enforce this
public health measure, especially when the evidence of benefit is marginal at
best.
Based on the points outlined briefly above,
the evidence has convinced me that the benefits of water fluoridation no
longer outweigh the risks. The money saved from halting water fluoridation
programs can be more wisely spent on concentrated public health efforts to
reduce dental decay in the populations that are still at risk and this will,
at the same time, lower the incidence of the harmful side effects that a large
segment of the general population is currently experiencing because of this
outdated public health measure.
Sincerely,
Dr. Hardy Limeback BSc PhD (Biochemistry) DDS
Head, Preventive Dentistry "
