Community Water Fluoridation Dr. Royal P. DeLegge Environmental Health Director Salt Lake County Health Department
Where Did This All Begin? The story of fluoridation begins with a mystery staining of the teeth first described by dentist Dr. Frederick McKay in Colorado in 1901 and, independently in Naples, Italy in 1902 by Dr. J.M. Eager, an American dentist stationed there.
Dr. McKay became aware of several cases that suggested that the water supply might be responsible for the staining. He also noted that decay rates were much lower in areas with endemic dental staining than they were in other adjacent areas.
In Essex, United Kingdom, a dentist named Norman Ainsworth had found local dental staining similar to McKay's description of “Rocky Mountain Mottled Teeth”. In a 1925 study Dr. Ainsworth examined more than 4,000 children and produced a statistical comparison of decay rates between populations with the staining and those without. This study showed that individuals living in areas where mottled teeth were most common tended to have a much lower incidence of dental decay.
The US Public Health Service investigated this relationship and appointed a dentist, Dr. H.T. Dean, to carry out the research. In a series of epidemiological investigations, Dr. Dean established that mottling of the teeth was extremely rare at fluoride levels of 1ppm or below, while there was a significant preventive effect for dental caries found at 1ppm.
Public health authorities in the United States decided to try and reproduce this effect in low-fluoride areas by adding fluoride to community water systems. No obvious negative health effects had been noted in those populations served by naturally fluoridated water.
Pilot Programs A number of pilot programs were set up to see whether the idea could work in practice. On 25th January 1945, Grand Rapids, Michigan, became the first town in the world to be artificially fluoridated. The previous year, a baseline study comparing Grand Rapids with the neighboring town of Muskegon had found similar decay levels in deciduous and permanent teeth in both areas. Six years later, surveys indicated that decay levels in 6 year-old children (i.e. those born since fluoridation commenced) in Grand Rapids was almost half of that in Muskegon. In July 1951, city officials in Muskegon decided to fluoridate that town's water supply.
Other Pilot Programs Newburgh, New York, started fluoridating in May 1945. Evanston, Illinois, began fluoridating in January 1946. As with the Grand Rapids scheme, these towns were paired with nearby “control” towns (Kingston, New York and Oak Park, Illinois) in order to measure the effectiveness of the fluoridation scheme. In both cases, significant reduction in dental decay rates were described in the fluoridating towns, with little or no change found in the control towns.
Early studies reported reductions in decay on the order of 50% or more. This was at a time when fluoridated water offered the only significant source of fluoride available to people.
Utah Fluoridation History In 1970, only 2.5% of Utah’s population had access to community fluoridated water systems and served fewer than 30,00 customers. Naturally fluoridated water systems supplied fewer than 3,000 persons.
Only five artificially fluoridated water systems were in place: Brigham City Helper Hill Air Force Base Two Native American Reservations
Opposition to Fluoridation There has been opposition to artificial water fluoridation since its inception. Opponents were concerned about placing a chemical, mandated by the government, into water supplies and posed numerous arguments over the need and expense of implementation. Also, since fluoride did not treat the water for safety, although it had a population-wide positive health effect, it was viewed as an unwarranted government intrusion on personal rights.
Utah Freedom from Compulsory Medication Act of 1976 “Public water supplies…shall not have fluoride or any of its derivatives or compounds, or any other medication added thereto without the approval of a majority of voters in a duly constituted election in the area affected thereby.”
1976 Act The Act moved the debate away from cost to effectiveness and safety. Concern was expressed that the issue was one of free choice, mass medication and government interference in the lives of citizens. The Act was passed in a statewide election with a 51.6% majority.
Pro-fluoridation groups continued to work to implement fluoridation at the local level, mostly in Northern Utah. The most active efforts were in Salt Lake and Davis counties.
Current Fluoridation Programs In November 2000 the voters passed a ballot initiative in Salt Lake County approving the fluoridation of public drinking water supplies. At the same time, an advisory referendum for fluoridation was passed in Davis County.
Fluoridation Status In the wake of the 2000 votes Utah moved from 50th in the nation, with 2.0% of the population fluoridated, to 39th with 54.3% of the population receiving fluoridated water.
Safety of Water Fluoridation The question of the safety of water fluoridation has been investigated time and time again by numerous national and international commissions. One of the most recent, and arguably the best, is the United Kingdom’s National Health Service Centre for Reviews and Dissemination in 2000, also known as the York Review. This meta-study provides a systematic review of more than 3,000 studies relevant to dental and general effects of water fluoridation on humans. The main conclusion was that there was no clear evidence of any adverse effect from water fluoridation other than staining of enamel (dental fluorosis).
Adverse Effect Claims Claims have been made that water fluoridation is linked to almost every conceivable condition known to medicine - and some conditions beyond. The range of allegations covers such diverse items as cancer, Alzheimer's disease, effects on salmon spawning, and even increasing crime rates in American cities. The fact that none of these have so far been found to have any substance should not be surprising; there are populations that have been drinking naturally fluoridated water at around 1ppm for centuries for whom no obvious adverse effects have been demonstrated.
Other forms of community fluoridation used worldwide Salt Milk Toothpaste Food & Beverages
Fluoridated Salt Several other methods have been evaluated for providing community water fluoridation. Fluoridated salt is used quite successfully and widely in Europe and South America. In situations where all salt in the economy is fluoridated, including that used in food production, its effectiveness comes close to that of water fluoridation. However, where fluoridated salt is simply provided on sale along with unfluoridated salt, its effectiveness on a population basis has been shown to be limited.
Milk Fluoridation Milk fluoridation programs have been implemented most notably in the United Kingdom and in Chile. In the Manchester, UK area, the Borrow Scheme was set up to provide fluoridated milk to primary school children. In Chile, fluoridated milk is provided through the health service rather than through schools. This method of fluoridation is quite promising but, while beneficial, the effect does not appear to provide as strong an effect as does water fluoridation.
Fluoridated Toothpaste A major method of fluoridation is, of course, the use of fluoridated toothpastes. It is estimated that in excess of 95% of toothpaste sales are of fluoridated products.
Current Fluoridation Regulations After the November 2000 ballot initiative in Salt Lake County and advisory referendum in Davis County, both local health departments worked to implement their mandates.
The Salt Lake Valley Board of Health adopted implementation target dates of by November 1, 2001 for surface water sources and January 1, 2002 for groundwater sources. • The Board also invited Salt Lake County water districts to a meeting to discuss the issues relating to implementation and agreed to form a Task Force comprised of representatives from each affected water district, SLVHD, UDOH, and UDEQ to work out implementation issues.
In July 2001 the Task Force recommended a new implementation date of October 1, 2003, which was accepted by the Board of Health. • The SLVHD Water Quality Bureau staff and Davis County staff worked together to develop local regulations, which were discussed with, and modified by, the Task Force over a period of more than a year.
In Salt Lake County, SLVHD Health Department staff members met with personnel of several water systems to devise methods of reducing costs by fluoridating only certain water sources, rather than all of the system’s sources, in ways that would still provide uniform concentrations throughout their systems. In the case of one system, Holliday Water, this reduced their estimated costs by more than 80%.
There are 14 systems that are actively fluoridating in Salt Lake County. Four other systems: Bluffdale, Draper, South Jordan, and the University of Utah, all import their water from fluoridated systems. • One system, Holliday Water Company, is not adjusting its fluoride levels above natural levels (of 0.4 ppm) as a result of legislative action that allows a privately held water company to decide its own fluoridation status. • Another system with a population over 3,300, White City Water, is not fluoridating due to its recognized status as a functionally separate system. The health regulation was amended to add such an exemption status. • The combined population served by fluoridated systems is approximately 96% of the county’s population that is served by water systems.
Fluoridation Chemical Impurities Much has been made of the source of, and impurities in, fluoridation chemicals (primarily hydrofluosilicic acid). Opponents have claimed that arsenic and lead are contaminants of concern.
Since implementation, opponents to water fluoridation have brought up a number of strategies to prevent or delay the implementation of community water fluoridation. One of the strategies is to question the quality and safety of chemicals used in the fluoridation process.
Hazardous Waste One claim regarding hydrofluosilicic acid used in water fluoridation is that it is a hazardous waste. The claim that hydrofluosilicic acid used in water fluoridation in the United States is a hazardous waste that has been redirected to water systems to avoid disposal issues is simply not true. The designation of hydrofluosilicic acid as hazardous material is due to its low pH (1.2). When considering the application rate of the chemical in drinking water supplies the pH hazard does not exist. There are numerous chemicals used in water purification, food production and preparation and the pharmaceutical industry that if discarded as waste would be classified as hazardous waste. None of these chemicals are designated as hazardous waste in their intended use.
Contaminants Two heavy metals, lead and arsenic, have been targeted as contaminants of fluoridation chemicals that would place the public at risk when the water is fluoridated. The question of arsenic contamination has been spurred with the lowering of the U.S. Safe Drinking Water Act maximum contaminate level (MCL) from 50 ppb (parts per billion or micrograms per liter [ug/L]) to 10 ppb.
Laboratory Analysis of Water at Weber Basin Treatment Plant ChemicalPre-fluoridationPost-flouridation Fluoride 0.1 mg/L 0.9 mg/L Arsenic <1.0 ug/L <1.0 ug/L Chromium <5.0 ug/L <5.0 ug/L Iron <0.02 mg/L <0.02 mg/L Mercury <0.2 ug/L <0.2 ug/L Silver <2.0 ug/L <2.0 ug/L Barium 0.0975 mg/L 0.0969 mg/L Copper <12.0 ug/L <12.0 ug/L Lead <3.0 ug/L <3.0 ug/L Selenium <1.0 ug/L <1.0 ug/L Jason, Karen, APC
Recent Legislative Action In 2013, the Utah legislature passed a law requiring original certification documents for fluoride chemicals added to community water systems. All of these chemicals are currently certified by NSF or UL.
Certification Documentation Original certification documentation for hydrofluorosilicic acid are readily available and have been obtained by water systems. Original certification documentation for sodium fluoride has been more difficult to secure.
Local History In 2010 the SLVHD and Board and Davis County Boards of Health, as a result of the biennial review and under recommendations by the CDC, decreased the targeted average annualized concentration of fluoride from 0.8 mg/L (ppm) to 0.7 mg/L (ppm).
The change to a lower annualized target concentration is to balance overall exposure to fluoride given the extraneous exposure now provided in the United States by processed foods and especially by soft drinks.
The change was also a response to an advisory that parents of infants under 6 months of age should consider reconstituting formula with unfluoridated water to reduce the already low possibility of dental fluorosis developing in deciduous teeth.
Dental fluorosis It is known that fluoridation of water supplies would be associated with low levels of enamel discoloration. Early studies predicted that very mild enamel fluorosis would affect a small proportion of a population receiving fluoridated water. The medical and dental communities have accepted that a low level of fluorosis is well worth the large reduction in dental decay brought about by fluoridation.
Dental fluorosis is a health condition caused by a child receiving too much fluoride during tooth development. The critical period of exposure is between 1 and 4 years of age; children over age 8 are not at risk. In its mild form, the most common, fluorosis appears as tiny white streaks or specks that are often unnoticeable to the untrained eye. In its severest form, also known as mottling of the tooth enamel, it is characterized by black and brown stains, and may include cracking and pitting of the teeth.
Mild case of dental fluorosis, visible as white streaks on the subject's upper right central incisor
Dental fluorosis is not a health problem but is considered only cosmetic. When it occurs it is treatable by a dentist. The incidence of fluorosis associated with community water fluoridation concentrations is negligible.