Tap water fluoridation has been around for over 65 years. But is it more harmful than beneficial? Many countries have already banned its use, so why hasn't the United States?

For many of us, water fluoridation is a matter of everyday experience, and we generally take its presence in our drinking water and its value in cavity prevention for granted. The first public water fluoridation occurred in the U.S. in 1945. Today, 67 percent of American communities have public fluoridated water systems. In fact, water fluoridation has spread thruout most of the developed world and is considered one of the ten greatest public health interventions of the twentieth century.¹

However, some think that water fluoridation should not be a fact of life, and that it represents both a trampling of civil liberties and an unrecognized threat to health. In fact, several countries have banned fluoridation including Sweden. While it’s true that those crying foul regarding civil liberties and labeling well-accepted prevention measures as threats or conspiracies (immunizations, for example) are often not all that well informed (read our article on the immunization debate), the fluoridation opponents have some science in their corner and they raise some interesting issues.  

Why do we have water fluoridation in the first place?

Dental caries, more commonly known as cavities, are often considered nothing more than a nuisance, another fact of life. However, the problem of dental caries is actually large, expensive and capable of diminishing quality of life. Dental caries is the most common chronic disease of childhood, five times more common than asthma and seven times more common than hay fever.²  

Tooth decay occurs when plaque, the film of bacteria that accumulates on teeth, produces acids that dissolve the hard enamel surfaces of teeth. If the acid damage is not stopped, the bacteria can penetrate through the enamel causing tooth decay. Cavities weaken teeth and can lead to pain, tooth loss, and widespread infection in the most severe cases.³  Ninety-two percent of adults ages 20 to 64 have had dental caries in their permanent teeth and 23% of adults ages 20 to 64 have untreated decay.⁴  People in families who make less money or who are less educated are more likely to experience tooth decay.  

In any one person’s individual experience, tooth decay may seem like a minor issue but, when the cost of treating everyone with tooth decay is added up, it’s a much bigger story. For example, one study projected that children missed nearly 52 million hours of school, or an average of 1.17 hours per child, in one year due to treatment problems.  During that same time, workers lost more than 164 million work hours, an average of 1.48 hours per worker, due to lack of treatment for dental disease.⁵ Plus, the cost of treatment is very high. Expenditures for dental services in the United States in 2004 totaled $81.5 billion, which was slightly more than 4% of the amount spent on healthcare that year.⁶  In short, dental caries is a serious problem that affects lives and budgets worldwide. 

Fluoride is a mineral that occurs naturally in most water supplies. Fluoridation is the adjustment of the natural fluoride concentration to about one part of fluoride to one million parts of water.  The concept of fluoridation came into play in the early part of the twentieth century when studies were done on children in Colorado and Texas who had brown, mottled teeth but far fewer cavities than comparable groups of children. The research determined that the children studied in Texas and Colorado were drinking water from water supplies that were highly fluoridated.  Thus, the connection between fluoride and cavity prevention was discovered. 

Fluoride prevents the acid produced by the bacteria in plaque from dissolving tooth enamel. Fluoride also allows teeth damaged by acid to repair themselves by adding minerals back to the tooth. Fluoride can’t repair cavities, but it can reverse low levels of tooth decay and in doing so, stop new cavities from forming.

The American Dental Association (ADA), the United States Public Health Service (USPHS), the American Academy of Pediatrics (AAP), and the World Health Organization (WHO), among many other national and international organizations, endorse community water fluoridation. According to the ADA, studies prove water fluoridation continues to be effective in reducing tooth decay by 20-40%, even in an era with widespread availability of fluoride from other sources, such as fluoride toothpaste.⁷ With that heavy hitting group of respected medical organizations supporting fluoridation, one would think that tap water fluoridation would be undisputed, but that’s not actually the case.

So, why does tap water fluoridation remain controversial?

Effectiveness is disputed

In fact, a number of respected scientists have compared dental caries rates in the U.S., Australia and other countries where fluoridation is widespread with the dental caries rates in countries where fluoridation is not permitted and found very little difference in rates of decay. It’s probably reasonable to believe that while water fluoridation is effective, other mechanisms for reducing dental caries have also become effective in the fight against tooth decay, possibly lessening the value of water fluoridation.

For example, Mark Diesendorf, an applied mathematician and health researcher in the Human Sciences Program at Australian National University and an expert in research design, has found, by comparing results from about 24 studies of unfluoridated districts in eight countries, that reductions in dental caries are just as great in nonfluoridated as in fluoridated areas.⁸ He (and others) theorized that improvements in diet, preventive dentistry and introduction of fluorides in toothpaste may explain the similarity in rates.  

Fluorosis

The brown mottling of teeth, known as fluorosis still occurs. In fact, according to the CDC, a nine percentage point increase in the prevalence of very mild or greater fluorosis to 33%,was observed among children and adolescents aged 6-19 years when data from 1999-2002 were compared with those from the National Institute of Dental Research 1986-1987 survey of school children.⁹  However, other studies have indicated that fluorosis does not seem to be tied to whether or not drinking water is fluoridated. A study in New York showed similar levels in fluoridated and non-fluoridated areas but at much lower rates of 11-18%.¹⁰  In fact, researchers believe that the current rise in fluorosis is primarily due to the increased use of fluoridated toothpaste and mouthwash, combined with children’s tendency to swallow toothpaste.  

Although proponents say that fluoridation does not necessarily contribute to fluorosis; opponents say that since there is already good access to fluoridation through oral hygiene products and supplementation, there is no need to fluoridate water. Beltran-Aguilar, D.M.D and his colleagues made this suggestion: " There may be a need to determine whether current enamel fluorosis prevalence warrants a re-evaluation and possible reduction in the fluoride concentration in water…on the premise that the fluoride concentration in water may be the most controllable of all fluoride modalities. Most overexposure to fluoride in the age groups at risk … comes from sources such as dietary supplements, or from sources not designed to be ingested, such as fluoridated toothpaste".¹¹ 

Toxicity of Fluoride

Fluoridation opponents point out that most studies of the effects of fluoride are done using pure, pharmaceutical quality fluoride. Water fluoridation, on the other hand, is achieved using commercial fluoride, a by-product of the chemical manufacture of fertilizer. Opponents say that the impurities can have an adverse effect on those who drink the water. However, there is very little evidence to back up the claim of harm from commercial grade fluoride, especially in the low concentration used.  

There is evidence that some parts of the population are at somewhat greater risk from the effects of over-ingestion of fluorides. Infants have a much lower tolerance for fluoride. Pediatricians recommend that fluoridated water not be used in the preparation of infant formula. Skeletal fluorosis, caused by excess fluoride buildup in the bones, causes arthritis-like symptoms. However, there are very few known clinical cases of skeletal fluorosis in the U.S. (six cases at the time of the study), according to a scientific review of EPA standards for fluoridation conducted by the National Research Council.¹²  

Individuals with kidney problems can be negatively affected by fluoride as well.  However, the National Kidney Foundation issued a study paper in 2008 with the following recommendation. “It would also seem prudent to monitor the fluoride intake of patients with chronic renal impairment, particularly those living in areas of high naturally occurring fluoride, children, those with excessive fluoride intake, and those with prolonged disease. There is insufficient evidence at this time to recommend the use of fluoride-free drinking water for all patients with renal disease".¹³  Proponents say that risks are very limited and affect a very small portion of the population.

Opponents say that it is unreasonable to subject vulnerable populations to risk in such a fundamental way as by “contaminating” their water supply. However, fluoridation opponents can take heart. Under mounting pressure the U.S. Department of Health and Human Services and the Environmental Health Agency, in its first regulatory change to water fluoridation in 50 years, announced on January 7, 2011 that they would recommend lowering the amount of fluoride in public water supplies, specifically replacing the range of 0.7-1.2mg of fluoride/liter of water to 0.7mg.¹⁴

Compromises Individual rights

Opponents also believe that “mass medication” of the water supply with a substance known to be toxic is a fundamental trampling of individual rights. Unlike many other public health measures which may ask people to make different choices (non-smoking areas, seatbelt usage and so on), water is a basic need and is difficult to obtain in sufficient quantity outside of public water systems.

They further point out that many industrialized nations have chosen not to fluoridate water, believing the practice to be unnecessary or dangerous or in opposition to civil liberties. Of interest, in the United States, the question of fluoridation is not a state or federal mandate. Communities make their own decisions about whether or not to fluoridate the water.

The following list of countries made the decision to fluoridate then, upon further review, chose to stop fluoridating. (Dates of initiating fluoridation and eliminating fluoridation in parentheses) ¹⁵

Federal Republic of Germany (1952–1971), Sweden (1952–1971), Netherlands (1953–1976), Czechoslovakia (1955–1990), German Democratic Republic (1959–1990), Soviet Union (1960–1990) and Finland (1959–1993).

This is truly a difficult issue and the pros and the cons are both compelling. Is there an answer?

Proponents claim that water fluoridation is the simplest, most cost-effective way to reach the greatest number of people with a preventive solution given the continued presence and cost of tooth decay.

Opponents suggest that there are enough readily available alternatives that are safer and more controllable. For example, fluoride supplementation through rinses or chewable tablets is frequently available through schools in areas where water is not fluoridated. They further point out that money spent on water fluoridation should be redirected towards better dental care for at-risk populations, especially better federal funding for dental work.

However, proponents say that those at greatest risk, those with low income or low education, are the least likely to have access to alternative methods for fluoridation, essentially building on the basis of the opposing argument by pointing out that many dentists will not accept lower levels of reimbursement.^16-18

The Bottom Line

The availability of fluoridated dental hygiene products combined with the susceptibility of vulnerable populations makes water fluoridation an outdated and clumsy mechanism for delivering prevention.

It makes better sense to intervene more directly with at-risk populations and in doing so, make progress towards the larger issue of eradicating tooth decay and eventually making tap water fluoridation unnecessary. Other countries have!

So, Is your tap water still fluoridated? Chances are if you live in the United States or Canada it is. Maybe, you should consider drinking bottled water, but it has its issues too. Better yet, maybe it's time to move!

Published March 18, 2011, updated July 19, 2012

Photo By:  William Murphy

About the Author:

Susan M. Brissette brings 30 years of experience in healthcare, ranging from positions as Chief Executive Officer and Chief Operating Officer in the acute care hospital setting to Senior Executive for a major national healthcare management company. Ms. Brissette holds a BS in Biology from Northeastern University and an MS in Health Policy & Management from the Harvard School of Public Health. She has lectured on healthcare management at the University of Massachusetts, developed a healthcare delivery system for a mining company in Cajamarca, Peru, and recently led the Afghanistan Public Health Redevelopment Task Force for the Washington Harvard Alumni Group. She has consulted on healthcare projects in Poland, Romania, Israel, Kuwait, Peru, Canada, and Mexico. She now owns and operates SB Cass Associates, a healthcare consulting firm located in upstate New York. Ms. Brissette’s consulting practice handles client projects ranging from business plan development for clinics, assisted living facilities, and clinical research groups to the development of market research reports for the pharmaceutical and biotechnology industries. She has written dozens of healthcare articles published on the internet and in national professional and consumer journals. She has also authored or edited online courses on HIPAA compliance, corporate security, childhood obesity, and business ethics.

Susan Brissette can be reached at SB Cass Associates [email protected]

References

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2.    Oral health in America: A report of the surgeon general, Executive summary, U.S. Department of Health and Human Services,  National Institute of Dental and Craniofacial Research, National Institutes of Health; 2000
3.    Fluoride and Water, KidsHealth
4.    The National Health and Nutrition Examination Survey, CDC, updated July 12, 2012
5.    ADHA Access to Care Facts & Stats, American Dental Hygienists' Association
6.    Dental caries prevention through oral fluoride supplementation, preventive medication, National Business Group on Health, November 17, 2011 
7.    Fluoride & Fluoridation, American Dental Association
8.    Hileman B, Fluoridation 0f Water, ”Chemical & Engineering News, Fluoride Action Network, Aug.1, 1988
9.    Beltrán-Aguilar ED et al, Surveillance for Dental Caries, Dental Sealants, Tooth Retention, Edentulism, and Enamel Fluorosis --- United States, 1988--1994 and 1999--2002, MMWR, August 26, 2005
10.   Kumar JV, Swango PA, Fluoride exposure and dental fluorosis in Newburgh and Kingston, New York: policy implications, Community Dent Oral Epidemiol 1999; 27: 171–80. C Munksgaard, 1999
11.   Beltrán-Aguilar ED et al, Prevalence and trends in enamel fluorosis in the United States from the 1930s to the 1980s,  Am Dent Assoc, Vol 133, No 2, 157-165. 2002 
12.   Fluoride in Drinking Water:  A Scientific Review of EPA's Standards, The National Academies Press, 2006    
13.   Fluoride Intake in Chronic Kidney Disease, National Kidney Foundation, April 15, 2008
14.   EPA and HHS Announce New Scientific Assessments and Actions on Fluoride / Agencies working together to maintain benefits of preventing tooth decay while preventing excessive exposure, News release-Water, EPA,  01/07/2011
15.   Water Fluoridation, Wikipedia
16.   McDonagh M et al, Systematic review of water fluoridation, BMJ 2000; 321 : 855 doi: 10.1136/bmj.321.7265.855 (Published 7 October 2000)
17.   Citizens for Safe Drinking Water, NoFluoride.com,
18.   Fluoride Action Network