Water fluoridation controversy
Water fluoridation controversy refers to debate surrounding the addition of fluoride to public water supplies. Calcium fluoride (CaF2) occurs naturally in the ground water in certain areas of the world. When water is artificially fluoridated, sodium fluoride (NaF), sodium silicofluoride (SFS) or fluosilicic acid (FSA) is added to raise the fluoride level to a range between .7 and 1.2 parts per million (ppm).
Despite the current stance of the medical and dental research associations, opponents charge that releasing fluoride compounds into municipal water supplies infringes on individual choice as to what a person ingests. They say water fluoridation is a scheme to dispose of industrial waste and this amounts to a mass dissemination of toxic substances.
Advocates of water fluoridation say that fluoridation is similar to fortifying salt with iodine, milk with vitamin D and orange juice with vitamin C and say it is an effective way to prevent tooth decay and improve oral health over a lifetime, for both children and adults. Opponents counter that there is no U.S. RDA (recommended dietary allowance) for fluoride  and claim industrial fluorosilicates are serious neurotoxic and mutagenic health hazards, even at the 1 part per million level deemed "optimal" by pro-fluoridation groups. The EPA Headquarters Union of Scientists say recent, peer-reviewed studies that document bone fractures, pediatric osteosarcoma, genetic mutations, lowered IQ, decreased kidney, thyroid and pineal gland functions, arthritis, osteoporosis and dental fluorosis requires an immediate halt to using the nation's drinking water reservoirs as toxic waste disposal sites. 

# Sodium fluoride and fluorosilicic acid
Webster's dictionary defines sodium fluoride as:
sodium+fluoride
Function: noun
Sodium fluoride is also one of the main ingredients in fungicides, rat and possum poison (sodium fluoroacetate, also known as "1080") and Sarin nerve gas (isopropyl-methyl-phosphoryl-fluoride).
The Material Data Safety Sheet (MSDS) for sodium fluoride (NaF) warns:
Section 3: Hazards Identification:
DEVELOPMENTAL TOXICITY: The substance may be toxic to kidneys, lungs, the nervous system, heart, gastrointestinal tract, cardiovascular system, bones, teeth. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated exposure to a highly toxic material may produce general deterioration of health by an accumulation in one or many human organs.
Over 90% of the fluoride compounds added to water are fluorosilicic acid (FSA) or sodium fluorosilicate (SFS), which are industrial byproducts of fluorine gas concentrates that are captured in pollution scrubbers during the manufacture of phosphate fertilizer. The phosphate ores used to make fertilizer are a natural source of radiation. During the manufacturing process, trace amounts of heavy metals, including lead, arsenic, mercury and radioactive nuclides such as uranium and radium are captured in the pollution scrubber and carried into the fluorosilicic acid concentrate. The radionuclides radon-222 and polonium-210 readily combine with fluorine, which is the most reactive element. As little as 0.03 microcuries (6.8 trillionths of a gram) of polonium-210 can be carcinogenic to humans. In addition, lead is absorbed like calcium in the body, where it can be stored in the bones for years before decaying and triggering a release of alpha radiation. Unless tests for specific isotopes are performed, no one would know that a transmutation had occurred from lead-214 to bismuth-214 and then to the highly radioactive polonium-214. Despite pro-fluoridation group's claims that fluorosilicic acid is comparable to a "vitamin" or "nutrient", the manufacturer's data sheet describes FSA as a DOT Class 6.1 Poisonous/Toxic substance, subject to hazmat regulations, with a maximum content of .020% heavy metals (as lead, or 1 part in 5000). In contrast, the EPA has a zero-level goal for lead in drinking water, with a new MCL (maximum contaminant level) of five parts per billion.

# EPA employee and citizen opposition
In 2005, eleven EPA employee unions representing over 7000 environmental and public health professionals of the Civil Service called for a moratorium on drinking water fluoridation programs across the country and asked EPA management to recognize fluoride as posing a serious risk of causing cancer in people. The unions acted following revelations of an apparent cover-up of evidence from Harvard School of Dental Medicine linking fluoridation with an elevated risk of osteosarcoma in boys, a rare but fatal bone cancer. 
In addition, over 1000 health industry professionals, including doctors, dentists, scientists and researchers from a variety of disciplines are calling for an end to water fluoridation in an online petition to Congress. 
Their petition highlights eight recent events that they say mandates a moratorium on water fluoridation, including a 500-page review of fluorides toxicology that was published in 2006 by a distinguished panel appointed by the National Research Council of the National Academies.  While the NRC report did not specifically examine artificially fluoridated water, it concluded that the US Environmental Protection Agency's safe drinking water standard of 4 parts per million (ppm) for fluoride is unsafe and should be lowered. Despite over 60 years of fluoridation without a single double-blind study of fluoride's effectiveness and many basic research questions that have never been addressed, the panel reviewed a large body of literature in which fluoride has a statistically significant association with a wide range of adverse effects.
Several prominent dental researchers and government advisors who were leaders of the pro-fluoridation movement have announced reversals of their former positions after they concluded that water fluoridation is not an effective means of reducing dental caries and that it poses serious risks to human health. The late Dr. John Colquhoun was Principal Dental Officer of Auckland, New Zealand. In an article titled, "Why I changed my mind about water fluoridation", he published his reasons for changing sides.  
Dr. Hardy Limeback, BSc, PhD, DDS was one of the 12 scientists who served on the National Academy of Sciences panel that issued the aforementioned report, Fluoride in Drinking Water: A Scientific Review of the EPA's Standards. Dr. Limeback is an associate professor of dentistry and head of the preventive dentistry program at the University of Toronto. He detailed his concerns in an April 2000 letter titled, "Why I am now officially opposed to adding fluoride to drinking water". 
In a presentation to the California Assembly Committee of Environmental Safety and Toxic Materials, Dr. Richard Foulkes, B.A., M.D., former special consultant to the Minister of Health of British Columbia, revealed:
"The  studies that were presented to me were selected and showed only positive results. Studies that were in existence at that time that did not fit the concept that they were "selling," were either omitted or declared to be "bad science." The endorsements had been won by coercion and the self-interest of professional elites. Some of the basic "facts" presented to me were, I found out later, of dubious validity. We are brought up to respect these persons in whom we have placed our trust to safeguard the public interest. It is difficult for each of us to accept that these may be misplaced." 
Despite various concerns by private citizens, government agencies such as the CDC and WHO continue to support water fluoridation as being a safe and effective means of reducing dental decay.

# Role in oral health
There are some groups which consider fluoride neither a vitamin nor an essential nutrient and claim that is the same belief held by the medical community.  Fluoridation opponents believe that excellent dental health can be maintained through alternative methods, such as modifying diet by consuming less sugar, chewing xylitol gum as is done in Europe, and good dental hygiene through flossing and brushing the teeth - even with fluoride toothpaste. They argue that since the effects of fluoride is primarily topical, there is no need to actually consume fluoride.  Furthermore, the benefits of fluoridated water do not outweigh the costs of systemic harm on the body. Consequently, they argue that there is no need to fluoridate the community drinking water.
Despite these claims, dental research has shown that fluoride has a positive effect on dental health.  During tooth development, fluoride binds to the hydroxyapatite crystals present in enamel and makes the enamel more resistant to demineralization by acids.  As a result, some organizations, such as the American Dental Hygiene Association, classify fluoride as a nutrient necessary for proper tooth development.  In addition, organizations, including the CDC and WHO, promote increasing the accessibility of fluoridated water.

# Use throughout the world
Water Fluoridation is prevalent in the United States.  Most developed nations previously fluoridated their water, but stopped or banned the practice.   Some examples are as follows.  The years when water Fluoridation started and stopped are in parentheses:
- German Federal Republic (1952-71)
- Sweden (1952-71)
- Netherlands (1953-76)
- Czechoslovakia (1955-1990)
- German Democratic Republic (1959-90)
- Soviet Union (1960-90)
- Finland (1959-93)
- Japan (1952-72)
In spite of this, the prevalence of dental decay has decreased in both Western Europe and the United States.  Some countries had water fluoridation but then abruptly stopped the practice. These countries, including the former East Germany, Cuba, and Finland, have continued to see drops in the incidence of tooth decay. Based on this evidence, opponents conclude that water fluoridation is unnecessary.
Though water fluoridation is promoted by many health organizations and is considered the least costly method of dispersing fluoride, other methods of dispersal are possible. In areas with complex water sources, water fluoridation is more difficult and more costly. Thus, other methods to fluoride are supported in those cases. The World Health Organization is currently assessing the effects of affordable fluoridated toothpaste, milk fluoridation and salt fluoridation in Africa, Asia, and Europe.
Moreover, a major concern of health organizations is the incidence of dental fluorosis, a sign of overexposure to fluoride. In many instances, natural fluoride levels in water are much higher than desired. These areas do not need fluoride added to water supplies, and health organizations endorse providing alternate water sources or adjusting the fluoride levels to deliver the proper amount for dental health instead.

# Effectiveness
Frequently, opponents point to a study by the National Institute of Dental Research showing little difference in tooth decay rates among children in fluoridated and non-fluoridated communities.  In the study's results, the difference between the children exposed to water fluoridation, and those who were not exposed, was very small, between 0.12 and 0.30 DMFS (Decayed Missing and Filled Surfaces).
Opponents also argue that in the instances that fluoride prevents tooth decay, the effects are merely topical.  Therefore, fluoridating water is unnecessary and ineffective.  Instead, they argue, direct applications of fluoride to teeth as done in dental offices and with fluoridated toothpastes should be the recommended methods.
Opponents point out that dental decay continues to exist in water fluoridated communities.  They reason that if fluoride is effective, then there would be no more tooth decay.  While, in theory, the poorest members of society would be aided the most by fluoridinated water, baby bottle tooth decay (BBTD) and tooth decay in general is still prevalent in those social groups.  Opponents conclude that, in light of the continuing dental health problem, water fluoridation is unable to successfully increase health standards and thus should not be used.
Finally, opponents argue that the general decline of tooth decay is the result of factors beside water fluoridation, including toothpaste with fluoride, improved diets, and overall improved general and dental health.
The Centers for Disease Control and Prevention published in its Morbidity and Mortality Weekly Report (MMWR) that starting or continuing water fluoridation decreased the incidence of tooth decay by 29%, and that stopping water fluoridation increased the incidence of tooth decay in some communities.  Other organizations also see a clear link between desired fluoride levels in water and a decrease in tooth decay.
In addition, since oral health is affected by many factors, fluoride alone would be unable, nor would it be expected, to eradicate the disease.  The social groups that would be more likely to benefit from water fluoridation are those living in poorer conditions, and an important factor to decrease dental health disparities may be water fluoridation programs.  Nonetheless, it is understood that these communities suffer from various problems which would impede oral health, such as lack of access to dental care and poorer oral hygiene education.  Water fluoridation is only a single factor to improve dental health.

# Safety
There are some opponents of fluoridation who believe fluoride is a poison that can lead to death or, more commonly, dental fluorosis in instances of overdose.  They argue that having a lethal chemical in the water is reckless and leads to many health problems in the general public.
These persons point to research which they say supports the notion that fluoride causes chromosomal damage and interferes with DNA repair.  They point to animal studies that they say demonstrate that rats fed for one year with 1 ppm fluoride in their water had detrimental changes to their kidneys and brains, an increased uptake of aluminum in the brain, and the formation of beta amyloid deposits, a characteristic of Alzheimers disease.  In animal studies, fluoride has been shown to inhibit melatonin production and promote precocious puberty.    Fluoride may have an analogous inhibitory effect on human melatonin production, as fluoride accumulates readily in the human pineal gland, the brain organ responsible for melatonin synthesis.   Further, it is argued by some opponents that fluoride can weaken the immune system, leaving people vulnerable to the development of cancer and AIDS.
Theses groups further emphasize that an overdose of fluoride is associated with liver damage, kidney function, and fluorosis in children.  At high doses, fluoride has many side effects.  Animal studies demonstrate that fluoride can damage the male reproductive system in various species.  Consequently, fluoride is considered dangerous by these groups.
Advocates of water fluoridation agree that fluoride in high concentrations produces harmful effects to the body.  Nonetheless, they argue that almost any substance is harmful because toxicity is based on the amount of exposure.  In defending water fluoridation, the American Dental Association points out that vitamin A, vitamin D, iron, iodine, aspirin, and water are potentially harmful if given in certain amounts.  As is true for all vitamins and minerals, recommended dosages for fluoride represent levels which maximize health benefits and minimize adverse effects.
The greatest concern with fluoride overexposure is dental fluorosis.  Fluorosis is undesirable because, in severe cases, it discolors teeth, causes surface changes to the enamel, and makes oral hygiene more difficult.  Government agencies, such as the Center for Disease Control and Prevention, keep records on the prevalence of fluorosis in the general public.  Also a concern, skeletal fluorosis is a disease in which fluoride deposits into bone, causing joint stiffness, joint pain, and sometimes changes in bone shape.  For skeletal fluorosis to occur, chronic, high level exposure to fluoride is required.  A mild form of skeletal fluorosis, osteosclerosis, is seen when levels of fluoride reach 5 parts per million (ppm) and the time of exposure lasts for 10 years.
In order to best prevent fluorosis, health organizations have created guidelines restricting the amount of fluoride exposure.  The United States Environmental Protection Agency limits the maximum amount of fluoride in drinking water to 4.0 milligrams per liter of water and recommends water supplies to contain between 0.7 and 1.2 milligrams of fluoride per liter.  The World Health Organization cautions that fluoride levels above 1.5 milligrams per liter leaves the risk for fluorosis.  When fluoride levels in water are low (usually below 0.6 ppm), fluoride supplements are sometimes prescribed to encourage healthy dental development.  There are accepted recommended guidelines on the amount of fluoride to prescribe, which depend on the fluoride levels in the drinking water and on the age of the child.
Moreover, health organizations have affirmed the currently accepted belief that recommended levels of fluoride does not contribute to the many diseases water fluoridation detractors accuse fluoride of causing.  The Centers for Disease Control and Prevention and the National Cancer Institute have both issued statements that water fluoridation is not believed to cause osteosarcomas.  Cancer in general is not believed to be caused from water fluoridation.
There is no clear link between Alzheimer's disease and water fluoridation.  A study in 1998 suggested a possible relationship between fluoride exposure and Alzheimer's disease.  Research groups point out that the study contained methodological limitations, which prevent a definitive conclusion on the subject. As a result, research and health agencies currently believe fluoride is not a risk factor for Alzheimer's disease, and instead age and family history are the most important risk factors.  Moreover, there is some research that suggests Alzheimer's disease can be prevented with water fluoridation because of the competition between aluminum and fluoride absorption.  Nonetheless, this research is also limited by design and no definitive conclusion of this effect can be made.
Other health concerns, such as kidney disease, Down syndrome, lead poisoning, heart disease, decreased fertility rates, and inhibition of biologic enzymes, are not believed to be attributed to water fluoridation.

# Reliance on experts
Many fluoridation opponents rely on experts opposing water fluoridation to validate their argument of the dangers of fluoride.  People, such as scientists and Nobel prize winners, are exemplified as a large knowledgeable group that have stated their opposition against water fluoridation.
In response, scientific and health organizations criticize opponents of water fluoridation for trying to engage in "polling practices" with research.  When a group opposing water fluoridation claims an award-winning researcher or dental expert agrees with them, the argument is supposed to be more convincing to the general public.  Researchers emphasize that voting or polling is not how scientific progress is made.  Thorough review of methodology and design of multiple studies over time lead researchers to conclusions.  Even in the critical analysis of these studies, content is the focus, rather than the researcher who led the study.
Another criticism of water fluoridation opponents given is their reference to research seeming to support their view.  Generally, those studies are criticized by the majority of scientific researchers on basic principles, such as the methodology used.  More problematic is the accusation that some anti-fluoridation research is published in journals, such as "Fluoride", that are deceptively made to appear peer-reviewed.

# Ethics
One aspect of opposition to water fluoridation regards the social or political implications of adding fluoride to public water supplies.  Setting aside the claim that water fluoridation may improve dental health, such an act would violate an individual's choice to pursue free choice of, or form of, medical treatment and it is argued that water fluoridation is "compulsory mass medication" because it does not allow proper consent.
It is also argued that, because of the negative health effects of fluoride exposure, mandatory fluoridation of public water supplies is a "breach of ethics" and a "human rights violation."  Litigation, both pro and con, has been a frequent outcome of forced water fluoridation.
Many advocates of fluoridation do not consider it a violation of people's right to consent to medical treatment.  They usually argue that fluoridation is not a form of mass medication because fluoride is naturally present in all water systems.  Opponents argue that the form of fluoride found in naturally fluoridated water supplies is not the same as the form used to artificially fluoridate water.  Likewise, opponents argue that the pharmacy grade fluoride used in many studies to support fluoride as a tooth decay preventative is not the grade used to fluoridate water. Frequently, those who promote water fluoridation make the comparison to the fortification of other types of foods, such as adding vitamins to breakfast cereals and baby foods.
In addition, proponents propose that preventing broad, easy access to fluoride is unethical.  Since the populations which benefit most from water fluoridation are children and those in poorer communities, fluoridation is considered an avenue to relieve some of the health disparities between socio-economic groups.  Fluoridation is defended further by its relative low cost.  The Canadian Task Force On Preventive Health Care describes water fluoridation as "the single most effective, equitable and efficient means of preventing coronal and root dental caries."  In the United States, the cost can be as low as 31 cents per person, per year.  As a result, many health organizations defend fluoridation and do not consider it a violation of ethical principles.

# Government and industry conspiracy
Some opponents point to a government conspiracy that has modified scientific research to further its own political goal. The particular conspiracy involves the secret development of the atomic bomb during World War II. The argument usually involves characterizing research as flawed or edited for the public in order to avoid public concern over military research. As some have put it, "The science of fluoridating public drinking water systems has been, from day one, shoddy at best . . . . the basis of that science was rooted in protecting the U.S. Atomic bomb program from litigation."
Other conspiracy theories involve large industrial companies wanting to rid themselves of fluorine "waste products". Some argue that fluoride is a waste product that is unusable and expensive to dispose of properly. Because of this expense, industrial companies desiring to protect their profits release "millions of tons of waste fluoride into the environment." As a result, these opponents of water fluoridation say, "it is now clear that the one utterly relentless force behind fluoridation is American 'big industry' ".
In spite of this, a large majority of government agencies and medical organizations support water fluoridation in locations needing fluoride supplementation and agree that it is a safe practice.  (See Medical approval for a list of health organizations.)  The Centers for Disease Control and Prevention (CDC) has listed water fluoridation as one of the ten greatest achievements in public health of the 20th century. In 2000, a report by the Surgeon General of the United States titled "Oral Health in America" stated, "Community water fluoridation remains one of the great achievements of public health in the twentieth century."  Various international groups, including the World Health Organization (WHO) and the International Association for Dental Research (IADR) support water fluoridation as a safe and effective method to fight tooth decay.

# Court cases

## United States
Fluoridation has spawned many court cases. Anti-fluoride activists have sued municipalities, claiming that their rights to consent to medical treatment, privacy, and due process are infringed by mandatory water fluoridation.  Individuals have sued municipalities for a number of illnesses that they blamed on fluoridation of the city's water supply. A substantial majority of courts have held in favor of cities in such cases, finding no or only a tenuous connection between health problems and widespread water fluoridation.  To date, no federal appellate court or state court of last resort (i.e., state supreme court) has found water fluoridation to be unlawful.

### Early cases
A flurry of cases were heard in numerous state courts in the 1950s during the early years of water fluoridation.  State courts consistently held in favor of allowing fluoridation to continue, analogizing fluoridation to mandatory vaccination and the use of other chemicals to clean the public water supply, both of which had a long-standing history of acceptance by courts.
In 1952, a Federal Regulation was adopted that stated in part, "The Federal Security Agency will regard water supplies containing fluorine, within the limitations recommended
by the Public Health Service, as not actionable under the Federal Food, Drug, and Cosmetic Act."
The Supreme Court of Oklahoma analogized water fluoridation to mandatory vaccination in a 1954 case. The court noted, "we think the weight of well-reasoned modern precedent sustains the right of municipalities to adopt such reasonable and undiscriminating measures to improve their water supplies as are necessary to protect and improve the public health, even though no epidemic is imminent and no contagious disease or virus is directly involved . . . . To us it seems ridiculous and of no consequence in considering the public health phase of the case that the substance to be added to the water may be classed as a mineral rather than a drug, antiseptic or germ killer; just as it is of little, if any, consequence whether fluoridation accomplishes its beneficial result to the public health by killing germs in the water, or by hardening the teeth or building up immunity in them to the bacteria that causes caries or tooth decay. If the latter, there can be no distinction on principle between it and compulsory vaccination or inoculation, which, for many years, has been well-established as a valid exercise of police power."
In the 1955 case Froncek v. City of Milwaukee, the Wisconsin Supreme Court affirmed the ruling of a circuit court which held that "the fluoridation is not the practice of medicine, dentistry, or pharmacy, by the City" and that "the legislation is a public health measure, bearing a real, substantial, and reasonable relation to the health of the city."
The Supreme Court of Ohio, in 1955's Kraus v. City of Cleveland, said, "Plaintiff's argument that fluoridation constitutes mass medication, the unlawful practice of medicine and adulteration may be answered as a whole. Clearly, the addition of fluorides to the water supply does not violate such principles any more than the chlorination of water, which has been held valid many times."

### Fluoridation consensus
As cases continued to be brought in state courts, a general consensus developed that fluoridation, at least from a legal standpoint, was acceptable.  In 1973's Beck v. City Council of Beverly Hills, the California Court of Appeal, Second District, said, "Courts through the United States have uniformly held that fluoridation of water is a reasonable and proper exercise of the police power in the interest of public health. The matter is no longer an open question." (citations omitted)

### Contemporary challenges
Though courts have consistently rejected arguments against fluoridation, advocates continue to challenge the spread of fluoridation.  For instance, in 2002, the city of Watsonville, California chose to disregard a California law mandating fluoridation of water systems with 10,000 or more hookups, and the dispute between the city and the state ended up in court.  The trial court and the intermediate appellate court ruled in favor of the state and its fluoridation mandate, however, and the Supreme Court of California declined to hear the case in February of 2006.  Since 2000, courts in Washington, Maryland, and Texas have reached similar conclusions.

## Republic of Ireland
In Ryan v. Attorney General (1965), the Supreme Court held that water fluoridation did not infringe the plaintiff's right to bodily integrity. However, the court found that such a right to bodily integrity did exist, despite the fact that it was not explicitly mentioned in the Constitution of Ireland, thus establishing the doctrine of unenumerated rights in Irish constitutional law.

# Medical approval
Although Japan, Germany, Sweden, Netherlands, Czechoslovakia, Cuba, and the former Soviet Union have stopped water fluoridation, and some reputable scientific organizations oppose water fluoridation, more than 100 national and international health service agencies and professional organizations see benefits in community water fluoridation as a means of preventing dental decay. They include:
- American Academy of Pediatric Dentistry
- American Association of Public Health Dentistry
- American Dental Hygienists Association
- American Dental Association
- American Public Health Association
- Australian Dental Association
- British Dental Association
- British Medical Association
- Canadian Dental Association
- Canadian Dental Hygienists Association
- Centers for Disease Control and Prevention (CDC)
- European Academy of Paediatric Dentistry
- FDI World Dental Federation
- International Association for Dental Research
- National Cancer Institute
- National Institute of Dental and Craniofacial Research
- World Health Organization

# Science reviews
There has only been one proper systematic review ever carried out. 
In the United Kingdom the Department of Health funded a systematic review in 1999, which looked at all of the evidence so far published, into the efficacy safety of adding fluoride to drinking water. This work was carried out at the University of York. They concluded:
The report was checked by the Medical Research Council (UK) after publication.
The current confused state can be better understood by the discovery of the  House of Commons Health Committee'  inquiry into 'The Influence of the Pharmaceutical Industry'  that medical students are seldom taught, neither here nor abroad,  how to properly go about evaluating  a research paper.  The committee  concluded: This implies a major deficiency in the education of healthcare professionals. 

# Characteristic errors
We are concerned about the continuing misinterpretations of the evidence and think it is important that decision makers are aware of what the review really found. As such, we urge interested parties to read the review conclusions in full at:
Occurrences of argumentum ad verecundiam and argumentum ad populum were not recognised for what they were.

# The precautionary principle
In order to fully prove and understand the nature of fluoridation risks (including the range of doses that can cause the effects, and how these doses vary based on environmental, genetic, and dietary factors) more research is required. But is it ethical to continue exposing entire populations to fluoride in their water while additional long-term studies are carried out to clarify the risks?
That is the crux of the question posed by an insightful analysis published in the March 2006 issue of the Journal of Evidence Based Dental Practice. The analysis, written by Joel Tickner and Melissa Coffin, examines the water fluoridation controversy in the context of the precautionary principle. The precautionary principle has become a core guiding principle of environmental health regulations in Europe and is based on the notion that:
"if there is uncertainty, yet credible scientific evidence or concern of threats to health, precautionary measures should be taken. In other words, preventive action should be taken on early warnings even though the nature and magnitude of the risk are not fully understood."
Without expressing any personal opinions about water fluoridation, Tickner and Coffin note that The need for precaution arises because the costs of inaction in the face of uncertainty can be high, and paid at the expense of sound public health.
In determining whether the precautionary principle should be applied to fluoridation, the authors note that:
- There are other ways of delivering fluoride besides the water supply;
- Fluoride does not need to be swallowed to prevent tooth decay;
- Tooth decay has dropped at the same rate in countries with, and without, water fluoridation;
- People are now receiving fluoride from many other sources besides the water supply;
- Studies indicate fluorides potential to cause a wide range of adverse, systemic effects;
- Since fluoridation affects so many people, one might accept a lower level of proof before taking preventive actions. 

# Pop culture references
- In Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, General Jack D. Ripper states that fluoridation is a communist plot: "Do you realize that fluoridation is the most monstrously conceived and dangerous Communist plot we have ever had to face?" 
- In the Justice League Unlimited episode "Question Authority", the Question, a conspiracy obsessed vigilante, is being tortured for information when he claims that fluoridation does not in fact prevent tooth decay, but does render one's teeth visible by spy satellite.