This position paper provides updated evidence for the many supportive policies held by the American Public Health Association (APHA) on community water fluoridation (CWF). This position paper provides the scientific basis and justification for the importance of continuing to support CWF for our nation’s public water supplies. It also emphasizes the critical role that public health practitioners, health care professionals, and policymakers can play with respect to this important public health practice. The position paper will enable APHA to continue as a policy leader for CWF and safe drinking water. The objectives of this position paper are for APHA to be well positioned to—
Relationship to Existing APHA Policies
The following APHA policies are updated and replaced by this position paper and are archived with the adoption of this resolution: 5005, 5508, 5904, 6912, and 7402.
The Problem
Tooth decay (dental caries) is one of the most common diseases in our country, affecting almost the total population. Although the scientific evidence base supports CWF as the foundation for improving a community’s public health by minimizing the prevalence and severity of tooth decay, many communities have not successfully initiated or continued this public health measure.1–4 Those opposed to fluoridation sow doubts about the risks and benefits of CWF, often with little scientific basis. In addition, there is often insufficient advocacy for CWF in the face of ongoing media campaigns by activists opposed to fluoridation, commonly referred to in the literature as antifluoridationists.2
Support for CWF
Since 1950,5 APHA has supported CWF as a safe and effective public health measure for the prevention of dental caries (tooth decay), reaffirming this policy in 1955,6 1956,7 1959,8 1963,9 1965,10 1969,11 1974,12 1975,13 1976,14 1977,15,16 1979,17 1980,18 1982,19,20 1992,21 1997,22 2000,23 2001,24 and 2006.25 In addition, more than 100 national and international organizations have recognized the public health benefits of community water fluoridation.26
Because of its health and economic benefits, CWF has been and is included in the 1990, 2000, and 2010 national health objectives (e.g., Healthy People 2010). Between 1992 and 2002, the proportion of the US population served by CWF increased from 62% to 67%. The Healthy People 2010 CWF objective 21–9 is to increase to 75% the proportion of the US population served by community water systems with optimally fluoridated water.27
Because many communities have not yet adopted fluoridation, the US Centers for Disease Control and Prevention (CDC) has set as a priority the evaluation of the effectiveness of laws, policies, and incentives related to water fluoridation and other public health measures designed to promote and sustain health for all residents across diverse community settings.31 However, opposition to this well-supported public health program continues to frustrate efforts by communities to begin or to continue fluoridation.2
Safety of CWF
The scientific evidence base continues to support CWF as a safe and effective public health measure. Reviews of the scientific literature on the health effects of fluoride in the last 18 years have been conducted by the National Health and Medical Research Council, Australian Government (2007)32; National Research Council (NRC), USA (1993, 2006)33,34; World Health Organization (1994, 1996, 2006)35–37; US Agency for Toxic Substances and Disease Registry (2003)38; International Programme on Chemical Safety; WHO (2002)39; Forum on Fluoridation, Ireland (2002)40; Medical Research Council, UK (2002)41; University of York, UK (2000)42,43; Institute of Medicine, USA (1999)44; Health Canada (1999)45; Lewis and Banting, Canada (1994)46; US Public Health Service (1991)47; and Kaminsky et al., New York State Department of Health (1990).48 In addition, the environmental impact of CWF has been reviewed.49,50 All of these reviews have found CWF to be safe and effective. Opponents have claimed potential toxicity from fluoridated water, but none of these claims has been supported by studies of scientific merit.2,51
Water safety is defined and determined by federal, state, and local regulations. The main federal law that ensures the quality of US drinking water is the Safe Drinking Water Act (SDWA). Under SDWA, the US Environmental Protection Agency (EPA) sets standards for drinking water quality and oversees the states, localities, and water suppliers who implement those standards. The current maximum contaminant level goal (MCLG) for fluoride in water is set at 4.0 mg/L,52 well above the optimal levels (0.7 mg/L F–1.2 mg/L F) currently recommended for CWF in the United States for the prevention of tooth decay.53 It has recently been recommended by a committee of the NRC that the MCLG of 4 mg/L for naturally occurring fluoride in water should be lowered to protect against the development of severe enamel fluorosis. The majority of the NRC committee concluded that the MCLG of 4 mg/L is not likely to be protective against bone fractures. Although the NRC committee concluded that the secondary maximum contaminant level of 2 mg/L adequately protects the public from the most severe stage of enamel fluorosis (enamel pitting), there were few studies to assess bone fracture risk in populations exposed to fluoride at the same level in drinking water. However, there was evidence that none of these concerns exist at the optimal levels of fluoride for the prevention of tooth decay.34
Fluorosilicic acid (FSA) is commonly used to fluoridate water. The majority of FSA samples have no impurities, and there is no credible evidence that the use of FSA is of concern.49,54,55
Legality of CWF
During the last 60 years, the legality of fluoridation in the United States has been thoroughly tested in our court systems.56 Fluoridation is viewed by the courts as a proper means of furthering public health and welfare.57 No court of last resort has ever rendered an opinion against fluoridation. The highest courts of more than a dozen states have confirmed the constitutionality of fluoridation.58 In 1984, the Illinois Supreme Court upheld the constitutionality of the state’s mandatory fluoridation law, culminating 16 years of court action at a variety of judicial levels.59 Moreover, the US Supreme Court has denied review of fluoridation cases 13 times, citing that no substantial federal or constitutional questions were involved.58
It has been the position of the US courts that a significant government interest in the health and welfare of the public generally overrides individual objections to public health regulation.1 Consequently, the courts have rejected the contention that fluoridation ordinances are a deprivation of religious or individual freedoms guaranteed under the Constitution.58,60 In reviewing the legal aspects of fluoridation, the courts have dealt with this concern by ruling that (1) fluoride is a nutrient, not a medication, and is present naturally in the environment; (2) no one is forced to drink fluoridated water because alternative sources are available; and (3) when a person believes that fluoridation interferes with religious beliefs, there is a difference between the freedom to believe, which is absolute, and the freedom to practice beliefs, which may be restricted in the public’s interest.61,62 Courts have consistently ruled that water fluoridation is not a form of compulsory mass medication or socialized medicine.58,61 Recent legal decisions have upheld CWF, including the use of FSA, that there is no fundamental constitutional right to fluoride-free water, and that the use of fluoride is not forced medication.63–66
Continued Benefit and Need for Fluoridation
There is a continued need for CWF to maintain and enhance the reduced prevalence and severity of dental caries. Dental caries remains the most prevalent chronic disease of childhood, with 28% of children aged 2 to 5 years affected by tooth decay. The incidence of dental caries is experienced by 6 of 10 adolescents (12–19 years) and more than 90% of adults (20–64 years).67 The prevalence and severity of dental caries has decreased significantly in the United States as a result of CWF and the nearly ubiquitous use of fluoride toothpaste. The US Task Force on Community Preventive Services strongly recommended CWF for the prevention of dental caries.68 The review that included 21 studies, considered good to fair quality, found a median decrease in dental caries of 29.1% (before-and-after measures) and 50.7% (after measures only) for children aged 4 to 17 years, with varying levels of baseline caries and socioeconomic status. The task force found the evidence of effectiveness was strong. Overall, the prevalence of dental caries among children aged 12 to 17 years declined from 90% in 1971 to 1974 to 67% in 1988 to 1991, and the mean number of teeth that were decayed, missing, or filled (DMFT) as a result of caries declined from 6.2 to 2.8 during this period. More recent data have been aggregated into different age groups of adolescents; for 12 to 19 year olds, the mean DMFT declined from 3.1 in 1988 to 1994 to 2.55 in 1999 to 2004. For 20 to 64 year-old adults, there continues to be a decline in the number of DMFT, from a mean of 12.5 in 1988 to 1994 to 10.3 in 1999 to 2004.67
Additional Considerations
Diffusion/Halo Effect
There is a benefit from the diffusion of fluoride from fluoridated communities to surrounding nonfluoridated communities via the export of bottled beverages and processed foods.69 This diffusion effect, also referred to as the halo effect, as well as additional sources of fluoride, have reduced the absolute and proportional benefit of water fluoridation, as measured between fluoridated and nonfluoridated communities, from approximately 60% in the 1950 to 1970 era to 18% to 40% since the 1980s. Based on 1986 to 1987 data,70 in regions where 75% of public water supplies are fluoridated, the benefit may not be apparent when measuring caries experience between fluoridated and nonfluoridated communities because of the halo or diffusion effect.71 However, in the Pacific region of the United States where less than 20% of public water supplies were fluoridated, there was a 60% difference in tooth decay experience between fluoridated and non-fluoridated communities.71 Continued CWF programs are essential to maintaining this improved oral health status.
Benefit for Adults
CWF benefits everyone in the community, including adults and seniors as well as children. The combined results of 9 studies (7853 participants) examining the effectiveness of water fluoridation in preventing tooth decay in adults were found to be significant at p < .001.72 Adults have more tooth and root surfaces at risk for tooth decay than children. The incidence of dental caries for adults equals or exceeds that of children.73,74 Griffin et al. summarized the need for placing increased attention on the prevention of tooth decay in adults72:
Although adults are as likely to experience new caries as children, certain segments of the US adult population—those with low incomes and the elderly—may have little or no access to restorative or preventive clinical care. At present, approximately 15% of state Medicaid programs provide no adult dental benefits at all, and approximately 45% cover only tooth extraction and emergency services (Oral Health America, 2003). Routine dental care is one of the few health areas not covered by Medicare. Limited access to restorative care increases the need for effective prevention; complications and pain and suffering are more likely if caries remain untreated. The proportion of the US population comprised of older adults is increasing, most of these persons are likely to be dentate and at risk for dental caries, and many lower-income adults lack access to timely restorative care. Our finding that fluoride is effective among all adults supports the development and implementation of fluoride programs to serve this population.72, p 414-5
Cost-Effectiveness
Fluoridation is a highly cost-effective means of preventing tooth decay in the United States, regardless of socioeconomic status.75–77 The cost of CWF can vary in each community depending on several factors: size of the community (population and water usage); number of fluoride injection points where fluoride will be added to the water system; amount and type of equipment used to add and monitor fluoride levels; amount and type of fluoride compound used, its price, and its costs of transportation and storage; and expertise of personnel at the water plant.78 The annual cost for a US community to fluoridate its water is estimated to range from approximately $3.00 per person in small communities to approximately $0.50 per person in large communities.76
Cost Savings of CWF
For communities of more than 20,000 people where it costs approximately $0.50 per person per year to fluoridate the water, every $1.00 (1995) invested in this preventive measure yields approximately $38 savings in dental treatment costs.79 At least 60% of the US population on public water systems has received fluoridated water since 1990, translating to savings in dental treatment costs of more than $25.7 billion between 1990 and 2000.80
In analyzing annual per person cost savings resulting from fluoridation, Griffin, Jones, and Tomar found a range from $16 in very small communities to $19 in large communities.76 These authors concluded, “On the basis of the most current data available on the effectiveness and cost of fluoridation, caries increment, and the cost and longevity of dental restorations, we find that water fluoridation offers significant cost savings.”76, p78
The annual incremental mean benefit of fluoridation has been found to be 0.19 tooth surfaces (range 0.04 to 0.34). This equates to a mean of 1.9 tooth surfaces every decade, or 9.5 tooth surfaces over 50 years.76 Preventing 10 tooth surfaces from decay translates into preventing the need for 10 fillings or perhaps two molars from needing crowns (a molar has five tooth surfaces). The tooth surface index (DMFS) does not address the severity of decay in any one surface or the need for treatment, which could vary from a small filling to a root canal treatment and crown or an extraction.
Disparities
Because of the multifactorial nature of tooth decay, oral health disparities within and between countries are related to sugar consumption, fluoride use, dental care, and social determinants of health.80 However, it has been shown that children with the greatest dental need and who are at highest risk for tooth decay benefit the most from water fluoridation.82–87 Therefore, CWF helps reduce disparities in tooth decay prevalence. This has been most eloquently and succinctly articulated by Burt: “There is no practical alternative to water fluoridation for reducing these disparities in the United States.”88, p195
Pre- and Post-Eruptive Benefits
Fluoridation protects teeth in two ways: systemically, when delivered through the water supply to children during the tooth forming years, and topically, through direct contact with teeth throughout life.89 Animal and human studies have demonstrated the topical and systemic benefits of fluoride.90,91 Epidemiological studies using data collected between 1991 and 1995 on children in Australia have confirmed earlier findings that higher pre- than posteruptive fluoride exposure is more beneficial for overall caries experience and for pit and fissure surfaces caries reduction. In those studies, children with optimum exposure to fluoridated water both pre- and posteruption had the lowest caries levels in all surface types and there was an exposure–response relationship between preeruptive exposure and caries.92–94
Total Fluoride Intake and Enamel Fluorosis
Enamel fluorosis is a biomarker of fluoride intake during tooth developing years. In a minority of children, fluoride exposure from birth through age 8, when teeth are forming, may result in changes within the outer surface of the tooth called enamel fluorosis. Fluorosis occurs only on primary and permanent teeth while they are forming under the gums; once the teeth come into the mouth, they are no longer able to develop this condition. Clinically, the appearance of enamel fluorosis may vary and is usually bilateral. In its mildest form, it appears as faint white lines or streaks visible only to trained examiners under controlled examination conditions. In its pronounced moderate form, fluorosis manifests as white mottling of the teeth in which noticeable white lines or streaks often have coalesced into larger opaque areas; brown staining of the enamel also may be present. In its most severe form, pitting and actual breakdown of the enamel may occur. The prevalence of severe enamel fluorosis is very low (near zero) at fluoride concentrations in drinking water less than 2 mg/L.95 In recent years, there has been an increase in the prevalence of children seen with nonsevere enamel fluorosis in both optimally fluoridated and nonfluoridated areas of the United States. The greatest relative increase in enamel fluorosis prevalence has occurred in nonfluoridated areas.96 Although US NHANES data from 1999–2002 have shown that 32% of US children aged 6 to 19 years have some enamel fluorosis,97 few survey participants had severe enamel fluorosis and less than 4% had moderate or severe enamel fluorosis. Although professional interest in limiting the amount of fluoride toothpaste delivered to young children and supervising their toothbrushing was expressed in the 1980s as a means of reducing the risk for enamel fluorosis, only during the early 1990s was this approach adopted broadly as a public health measure, which was too late to alter the risk for fluorosis among the 12 to 19 year age cohort in NHANES 1999–2002.97 Although it has been estimated that only approximately 2% of US schoolchildren may experience perceived esthetic problems related to enamel fluorosis that could be attributed to the currently recommended levels of fluoride in drinking water,98 in more recent studies, it has been found that mild fluorosis does not have a negative association on the perception of dental appearance.99 Children and their parents who had mild fluorosis were even better off in perception of oral health when other factors were controlled for in multivariate models. This rather unexpected finding, the authors suggest, might be explained by the fact that better oral health was often perceived as being without caries.99
Various studies in Canada, Australia, and the United States have shown a relationship between young children swallowing too much fluoride from fluoride toothpaste and subsequent enamel fluorosis development.96,100,101 In a study of 10- to 14-year-old children in Massachusetts and Connecticut, Pendrys found that enamel fluorosis in the optimally fluoridated study sample was attributed to early toothbrushing behaviors, inappropriate fluoride supplementation, and the use of infant formula in the form of a powdered concentrate.96 Enamel fluorosis in the nonfluoridated study sample was attributed to fluoride supplementation under the pre-1994 protocol and early toothbrushing behaviors. In the nonfluoridated study sample, 65% of the enamel fluorosis cases were attributed to fluoride supplementation under the pre-1994 protocol. An additional 34% was explained by the children swallowing fluoride toothpaste when they brushed more than once per day during the first 2 years of life. In the optimally fluoridated study sample, 68% of the enamel fluorosis cases were explained by the children using more than a pea-sized amount of toothpaste during the first year of life, 13% by having been inappropriately given a fluoride supplement, and 9% by the use of infant formula in the form of a powdered concentrate. Recommendations have been made to reduce the occurrence of enamel fluorosis by controlling identified risk factors.78
Fluoride Intake From Foods and Beverages
Water and water-based beverages are the chief source of dietary fluoride intake. Conventional estimates are that approximately 65% to 75% of dietary fluoride comes from water and water-based beverages.102 In 1997, the Food and Nutrition Board of the Institute of Medicine developed a comprehensive set of reference values for dietary nutrient intakes.44 The adequate intake (AI) establishes a goal for intake to sustain a desired indicator of health without causing side effects. In the case of fluoride, the AI is the daily intake level required to reduce dental decay without causing moderate enamel fluorosis. The AI for fluoride from all sources (fluoridated water, food, beverages, fluoride-containing dental products and dietary fluoride supplements) is set at 0.05 mg/kg/day.44 Using the established AI of 0.05 mg/kg, the amount of fluoride for optimal health to be consumed each day has been calculated by gender and age group (expressed as average weight).103 The tolerable upper intake levels (UL) are higher than the AI and are not the recommended level of intake. The UL is the estimated maximum intake level that should not produce unwanted effects on health. The UL for fluoride from all sources (fluoridated water, food, beverages, fluoride-containing dental products and dietary fluoride supplements) is set at 0.10 mg/kg/day for infants, toddlers, and children through 8 years of age. For older children and adults, who are no longer at risk for enamel fluorosis, the UL for fluoride is set at 10 mg/day, regardless of weight.44
Dietary fluoride intakes by adults from food, water, and beverages, where the concentration is 1.0 parts per million (ppm) fluoride in water, range from 1.4 to 3.4 mg/day; where the concentration is less than 0.3 ppm fluoride, the range is from 0.3 to 1.0 mg/day.44 USEPA has set the MCLG for fluoride in drinking water at 4 mg/L; by converting the MCLG of 4.0 mg/L to a mg/kg/day basis using standard water consumption estimates and body weight data from the NHANES III survey, EPA has concluded that dietary exposure to fluoride, including food exposure to sulfuryl fluoride used as an insecticide, uses 35% of the MCLG (expressed as mg/kg/day) for the US population; 23% of the MCLG (expressed as mg/kg/day) for youth 13 to 19 years, 37% of the MCLG (expressed as mg/kg/day) for children 3 to 5 years, 28% of the MCLG (as mg/kg/day) for children 1 to 2 years, and 35% of the MCLG (expressed as mg/kg/day) for all infants younger than 1 year old. These risk estimates are below the USEPA’s level of concern.104
Infant Formula and the Risk for Enamel Fluorosis
Although only a small factor in the risk for enamel fluorosis, the American Dental Association (ADA) (and the CDC) has issued guidance for parents and caregivers of infants younger than 12 months of age to consult with their pediatrician, family physician, or dentist on the most appropriate type of water to use to reconstitute infant formula.105 Recent evidence suggests that mixing powdered or liquid infant formula concentrate with fluoridated water on a regular basis for infants primarily fed in this way may increase the chance of a child’s developing the faint white markings of very mild or mild enamel fluorosis. Occasional use of water containing optimal levels of fluoride should not appreciably increase a child’s risk for fluorosis. Studies have not shown that teeth are likely to develop more esthetically noticeable forms of fluorosis, even with regular mixing of formula with fluoridated water.106
CWF and Fluoride Toothpaste
Because frequent exposure to small amounts of fluoride each day will best reduce the risk for dental caries in all age groups, all people are recommended to drink water with an optimal fluoride concentration and to brush their teeth twice daily with fluoride toothpaste.78 Fluoride is the only nonprescription toothpaste additive proven to prevent dental caries.78 Because water fluoridation is not available in many countries, toothpaste might be the most important source of fluoride globally.78 There is an additive benefit of fluoride toothpaste. Combined use of fluoride toothpaste and fluoridated water offers protection greater than either used alone.78 In the United States, the standard concentration of fluoride in fluoride toothpaste is 1,000 to 1,100 ppm. Fluoride toothpaste is helpful to all age groups and should be used at least twice a day. Since 1991, manufacturers of fluoride toothpaste marketed in the United States have, as a requirement for obtaining the ADA Seal of Acceptance, placed instructions on the package label stating that children aged younger than 6 years should use only a pea-sized amount of fluoride toothpaste. This is reported to sharply reduce the role of fluoride toothpaste as a risk factor for enamel fluorosis.107 Toothpaste labeling requirements mandated by FDA in 1996 also direct parents of children aged younger than 2 years to seek advice from a dentist or physician before introducing their child to fluoride toothpaste.108 Children younger than 6 years of age should have parents supervise and apply the toothpaste so as to limit the amount that may be swallowed; fluoride toothpaste should be spit out rather than swallowed.
The propensity of young children to swallow toothpaste has led to development of “child-strength” toothpaste with lower fluoride concentrations. Such a product, not currently available in the United States, would be a desirable alternative to currently available products for many young children. Toothpaste containing 500 to 550 ppm fluoride might be almost as efficacious as that containing 1,000 ppm fluoride.109 A British study reported that the prevalence of diffuse enamel opacities (an indicator of mild enamel fluorosis) in the upper incisors was substantially lower among children who used toothpaste containing 550 ppm fluoride than among those who used toothpaste containing 1,050 ppm fluoride.110 An Australian study reported a decrease in the prevalence of enamel fluorosis and no increase in caries after steps were taken to promote use of toothpaste for children containing 400 ppm fluoride and reduce dosages for dietary supplements.111
Adults benefit considerably from CWF and fluoride toothpaste. A review of adult studies after 1980 found that any fluoride, whether self-applied, professionally applied, via water fluoridation, or in combination, averted 0.51 carious coronal and root surfaces per year.72
Fluoridation and Dental Sealants
The effectiveness of dental sealants in community-based programs may be further improved when coupled with lifetime exposure to optimally fluoridated water.112
Bottled Water
In 2006, the FDA’s Center for Food Safety and Applied Nutrition issued a Health Claim Notification for Fluoridated Water and Reduced Risk of Dental Caries.113 Labels on bottled water with 0.6 to 1.0 mg/L fluoride may claim “Drinking fluoridated water may reduce the risk of [dental caries or tooth decay].” In addition, the health claim is not intended for use on bottled water products specifically marketed for use by infants.
Because the use of bottled water has increased and because the majority of commercial bottled water is low in fluoride, there is the potential for an increase in dental caries.114,115 To encourage bottled water manufacturers to provide optimally fluoridated water, the ADA has introduced a certification program for foods and beverages that are beneficial to oral health, including fluoridated bottled water.116
Per capita consumption of bottled water has increased from approximately 190 mL/person/day in 2001 to approximately 285 mL/person/day in 2006.117 Considering water from all sources, EPA surveys in 1994 to 1998 found the mean per capita daily average total water ingestion was 1.233 L.118 In the EPA surveys, 75% was from community water, 13% from bottled water, 10% from other sources (e.g., well, spring, and cistern), and 2% from unidentified sources. Assuming no general increase in overall water consumption, bottled water use has increased from 15% in 2001 to 23% in 2006 as a proportion of total water consumption. ADA recommends that dentists ask their patients about bottled water use and advise them about the possible removal of fluoride by some home water treatment systems.118 Further, ADA and CDC recommend labeling of bottled water with the fluoride concentration of the product.78,119
Salt Fluoridation
Salt fluoridation is practiced as a community-based alternative to water fluoridation in many countries where there are few central water systems, water infrastructure is otherwise not appropriate, or where other factors preclude the use of water fluoridation. It has been estimated that 40 million people use salt fluoridation, mainly in European, South American, and Central American countries.120 A concentration of 200 to 250 mg fluoride per kg salt is typically used in fluoridated salt. It is recommended that a national fluoride program use only one of these approaches.121
Fluoride Supplements
Where community water fluoridation is not feasible because there is no central water supply or because there are a large number of wells and a small population, school-based fluoride supplement programs are an alternative for communities with suboptimal fluoride in drinking water.122 Prescription fluoride supplements (of 0.25 mg/day, 0.5 mg/day, or 1 mg/day, depending on the age of the child and the concentration of fluoride in the water supply—whether less than 0.3 mg/L or between 0.3 and 0.6 mg/L, and all sources of fluoride) are currently recommended daily for children between 6 months of age and 16 years where the fluoride concentration of the water supply is less than 0.6 mg/L (ppm).78 Currently, in addition to age and fluoride concentration of drinking water, all sources of fluoride should be evaluated with a thorough fluoride history when physicians or dentists prescribe fluoride supplements. Patient exposure to multiple water sources can make proper prescribing complex.123
Home compliance with use of fluoride supplements can be challenging. Health care providers must educate parents, or school personnel in the case of school-based programs, about the appropriate use of the fluoride supplements; moreover, parents and recipients must understand the importance of fluoride supplements, the recommended dose, and the need for compliance on a daily basis for many years. Concomitantly, fluoride supplements are not always prescribed as recommended; studies have found more than one third of children receive prescriptions with incorrect dosage o
