Tenth Meeting 12th July 2001
Presentation by Dr Jacinta McLoughlin
Presentation by Mr Tom Reeves
Presentation by Dr Caswell Evans
Presentation by Dr Jacinta McLoughlin
Dental School, Trinity College, Dublin
Dr McLoughlin made a presentation on a section of the Department of Health and Children contract for the evaluation of oral health services. The Dublin School of Dental Science section of Lot 2 of this contract is concerned with the fluoridation of public water supplies, the aim of which is to carry out an evaluation of quality and performance of the fluoridation of public water supplies with regard to structure, process and outcomes, in order to determine best practice methodologies appropriate to all aspects of water fluoridation.
Progress to Date
Meetings have taken place with officials from the Department of the Environment and Local Government and the Environmental Protection Agency.
Information has been collected by means of questionnaires to Principal Dental Surgeons, and Principal Environmental Health Officers and Public Analyst Laboratories.
Water fluoridation test results have been obtained from the Department of Health and Children, the Society of Chief and Principal Dental Surgeons and from the Environmental Protection Agency.
Situation analysis of selected water treatment plants
Nine plants have been visited in 5 health board regions.
Draft report and recommendations
Dissemination of agreed report
Dr McLoughlin then spoke about some of the information received by means of the questionnaires mentioned above. Questionnaires for Principal Dental Surgeons and Environmental Health Officers yielded information on Fluoride Monitoring Committees (FMC), reporting of test results, funding for water fluoridation and details of the schemes involved.
The Fluoride Monitoring Committees (FMC) were established in 1992 with the following terms of reference:
- Improving the day to day operation of the fluoridation programmes
- Improving test results
- Monitoring the current and future need for new / replacement plant
Information received on the FMC from the Principal Dental Surgeons and Environmental Health Officers was as follows:
- 83% reported FMC moderately or very effective
- 72% visit plants regularly or occasionally
- Principal Environmental Health Officer is the key link between the health board and the local authority
- 74% of reports of public analysts’ tests are received within 1 month
- 57% produce an annual report
- 54% of FMC determined capital needs.
Dr McLoughlin then presented results of monthly test results from the former Eastern Health Board and the Western Health Board in 1999. Results are grouped into four bands: < 0.7; 0.7 to less than 0.8; 0.8 to 1.0, >1.0 to 1.1 and >1.1ppm. Results in the 0.7 to less than 0.8 band and greater than 1.0 to 1.1 are reported as marginal by the Department of Health and Children.
In 1999, in the Eastern Health Board the vast majority of results were in the 0.8 to 1.0 band. In the Western Health Board results were more widely distributed, with a number of results in both the < 0.7 and > 1.1 ppm bands. The accuracy of instrumentation is reflected in the results.
At the time of this presentation nine water fluoridation plants had been visited in five health boards, and a visit to a Southern Health Board plant was planned. The plants visited serve populations from a few thousand to over a hundred thousand. The company supplying the hydrofluosilicic acid was also visited in New Ross.
Dr McLouglin proceeded to speak on the assessment of the water treatment plants and detailed the type of information being collected under the following headings:
Water treatment plant assessment
Current practice on pre-treatment water testing
Procedures for intake of acid, including health and safety aspects
Bunding and security of storage tanks
Procedures for dealing with spillages
Equipment and preventive maintenance
Types of pumps, model and year of installation
Measurement of flow rate, procedures for altering the flow meter
Alarms and back-up pumps
Programme of preventive maintenance: internal or external and frequency
Incident management and monitoring visits
Procedure for incidents
Recording of incidents
Reporting of incidents
Audits by Health and Safety Authority
Visits from local authority engineers, Environmental Health Officers and Principle Dental Surgeons.
Testing and Calibration
Testing and recording of results
Equipment used, frequency and personnel
Action taken if unsatisfactory
Calibration frequency, internal / external, of test equipment and flow meter.
Personnel and training
Numbers of personnel
Part time or full time
Level of training
Dr McLoughlin spoke about the key issues to be addressed in the report, which will focus on the areas of data collection and recording, the interagency management and the operation of the water treatment plants. Recommendations will be made about identification (alphanumerically) of water treatment plants, schemes (including supplemental and group schemes) as well as maps of the distribution networks. All water treatment plants will be identified alpha numerically as will supplemental supplies and group schemes; maps of distribution networks will be produced.
With regard to inter-agency management the report will look at the remit of the Fluoride Monitoring Committees. The personnel responsible for the operation of these committees will be identified and their roles explained. This will be looked at in light of the pending changes in local authority structures.
A code of practice for water treatment plants is proposed similar in nature to the US Department of Health and Human Services, Engineering and Administrative Recommendations for Water Fluoridation 1995. (27) Quality assurance programmes, to include health and safety audits and training topics will be recommended in the final report.
Since 1997 Mr Tom Reeves has been the National Fluoridation Engineer, in the Division of Oral Health Program, at the Centre for Disease Control and Prevention in the United States.
Mr Reeves delivered a presentation entitled ‘Engineering / Technical Aspects of Water Fluoridation’.
He outlined how the history of water fluoridation is a classic example of clinical observation leading to epidemiological investigation and community based public health interventions. He pointed out that although other products containing fluoride are available, water fluoridation remains the most equitable and cost effective method of delivering fluoride to all members of most communities, regardless of age, educational attainment or income level.
He recalled how in 1999, the Centres for Disease Control and Prevention (CDC), Atlanta, Georgia, called fluoridation one of the ten great achievements in Public Health in the 20thcentury.
Mr Reeves initially discussed the fluoride chemicals used in the US, and how they are manufactured. He pointed out that at times there is confusion about the correct name for the fluoride chemicals. Over the years many versions have been used but at the moment for standardisation of transport etc. the term fluorosilicic acid is used.
Chemicals used in Water Fluoridation
All the fluoride chemicals used in the U.S. for water fluoridation, sodium fluoride, sodium fluorosilicate and fluorosilicic acid, are useful by-products of the phosphate fertilizer industry.
The manufacturing process produces two by-products:
A solid, calcium sulfate (sheet rock, CaSO4) and
Two gases: hydrofluoric acid (HF) and silicon tetrafluoride (SiF4)
A simplified explanation of the manufacturing process follows:
Apatite rock, a calcium mineral found in central Florida, is ground up and treated with sulphuric acid, producing phosphoric acid and two by-products, calcium sulfate and two gas emissions. These gases are captured by product recovery units (water spray) and condensed into 23% fluorosilic acid. Sodium fluoride and sodium fluorosilicate are made from this acid.
Mr Reeves then made the point that it is the inorganic form of ionic fluoride that is used in water and is the one that is responsible for the prevention of dental caries.
The equipment employed to feed the fluoride chemicals into the water systems in the U.S. was next discussed.
Fluoride chemicals are always added to a water supply as liquids, but they may be measured either in liquid or solid form. The solid form must be dissolved into a solution before entering the water supply system.
There are three general methods of adding fluoride chemicals.
- Dry feeders can add sodium fluoride or sodium fluorosilicate
- Acid feed systems will add fluorosilicic acid
- Saturators will add sodium fluoride.
The choice of feeder system depends on the fluoride chemical used and the amount to be fed. The rate of feed will depend on the desired fluoride content of the untreated water. Dry feeders are used for medium sized water plants.
Fluorides can be fed into a water supply in the following ways:
- The amount of dry chemical compound (usually fluorosilicate) can be measured with a machine, then added to a mixing tank (tank solution) where it is thoroughly mixed and then delivered to the main flow of water.
- A small pump can be used to add solutions of fluorosilicic acid directly to the water supply system. (carboy / bulk)
- Saturated solutions of sodium fluoride in constant strengths of four percent can be produced in a saturator tank at almost any temperature of water encountered in the usual water plant. This saturator solution can be pumped with a small solution feeder (metering pump) directly into the main water of a water supply system.
- Unsaturated solutions of sodium fluorosilicate or sodium fluoride may be prepared by weighing amounts of compounds, measuring quantities of water, and thoroughly mixing them together. This method of feeding fluorides is not desirable and is discouraged by CDC.
There are two types of dry feeders: volumetric dry feeders and gravimetric dry feeders.
Gravimetric feeders discharge chemicals at a constant weight rather than at a constant volume during a given time period. They are extremely accurate but are
much more costly.
Volumetric feeders essentially consist of a combination of a driving mechanism for delivering a constant volume of dry compound, a hopper for holding the compound and a chamber, solution tank for dissolving the compound before discharge into the water supply.
Acid feed systems consist of a small container (carboy) set on scales and a small metering pump adds the acid directly to the water supply system. This system is used in ground water systems, like well houses.
The bulk acid feed system is a fluoride feed system in larger water plants that uses bulk storage of fluorosilicic acid and is similar to the carboy system used in ground water supplies. The difference is that a large bulk storage tank (4,000 to 5,000 gallons) is added and a day tank is necessary instead of a carboy. Under normal operating conditions, the day tank should not contain over 2 to 3 days’ supply of acid.
The saturator feed system is a type of chemical feed system that is unique to fluoridation. The principle is that a saturated fluoride solution will result if water is allowed to run through a bed of sodium fluoride. A small pump then delivers this saturated solution of sodium fluoride into the water supply system. There are two types of saturators used in the U.S., the up-flow and down-flow saturators.
Toxicity, purity and risk to humans
Mr Reeves then spoke about concerns around toxicity, purity and the risk to humans from the addition of fluoride chemicals to drinking water. He made the point that all of the over 40 water treatment chemicals that may be used in water treatment plants are toxic to humans in their concentrated form, e.g., chlorine gas, and the fluoride chemicals are no exception. Added to drinking water in very small amounts, the fluoride chemicals dissociate virtually 100% into their various components (ions) and are very stable, safe, and non-toxic.
Mr Reeves proceeded to address the issue of concerns about the impurities in fluoride chemicals and detailed the organisations, which have set standards for quality and safety of water treatment chemicals.
The American Water Works Association (AWWA) and the American National Standards Institute (ANSI) set the following standards for all chemicals used in water treatment plants:
ANSI/AWWA B701 – 99 (sodium fluoride)
ANSI / AWWA B 702 – 99 (sodium fluorosilicate)
ANSI / AWWA B 703 – 00 (fluorosilicic acid)
The National Sanitation Foundation (NSF) also sets standards and produces product certification for products used in the water industry, including fluoride chemicals.
The ANSI / NSF Standard 60 sets standards for purity and provides testing and certification for the fluoride chemicals. This standard provides for product quality and safety assurance that aims to prevent the addition of harmful levels of contaminants from water treatment chemicals. More than 40 states have laws or regulations requiring product compliance with Standard 60.
Claims about arsenic in drinking water
To illustrate the stringency of these standards and the compliance with them, Mr Reeves referred to levels of arsenic in drinking water. According to the National Sanitation Foundation (NSF) tests, arsenic was not detectable in most of the samples tested; those samples that did have detectable levels of arsenic, had an average of 0.43 µg / L (parts per billion) in the drinking water attributable to the fluoride chemical. The U.S. Environmental Protection Agency (EPA) has set a Maximum Contaminant Level (MCL) of 50 µg / L, and have proposed to lower their MCL to 10 µg / L. The arsenic level referred to above is less than 10% of the proposed lower MCL level.
An individual would need to drink 10 to 20 gallons of water a day in order to consume 20µg / L of arsenic.
In the U.S. water companies are able to specify when purchasing fluosilicic acid that they want a chemical with zero levels of arsenic in it. This product is more expensive, however, but is readily available.
Tests by NSF and other independent testing laboratories have shown no detectable levels of radionucleotides in drinking water
Mr Reeves next dealt with the issue of the use of ‘industrial grade’ rather than ‘pharmaceutical grade’ fluoride chemicals. He pointed out that the water supply industry is considered an industry and all chemical used in the water plant are industrial chemicals including fluoride. All the standards of AWWA, ANSI and NSF apply to these industrial grade chemicals to ensure they are safe. Pharmaceutical grade compounds are not appropriate for water fluoridation and are used in the formulation of prescription drugs.
The next topic covered was that of silicifluorides. Some people hold the belief that silicofluorides do not completely dissociate under conditions of normal water treatment and thus cause health problems. Mr Reeves referred to work carried out by the U.S. Environmental Protection Agency (EPA) and CDC epidemiologists in which research made the above assumptions. No credible evidence was found to support these claims.
He made the point that because silicofluoride dissociates completely in water, health studies using sodium fluoride are applicable here. The EPA has not set any Maximum Contaminant Levels (MCL) for the silicates as there is no known health concerns for them at the low concentrations found in drinking water.
Claims about lead in drinking water
At this stage Mr Reeves dealt with two studies by Dr Roger Masters and Myron Coplan, which showed an effect of silicofluorides used in water fluoridation on blood lead levels. (28) The CDC was unimpressed by these ecological studies, which failed to offer any credible evidence of an effect. A paper was written in response to the above study by Urbansky and Schock which concluded that no credible evidence exists to show that water fluoridation has any quantitatable effects on the solubility, bioavailability, bioaccumulation or reactivity of lead or lead compounds. (29)
Therefore, based on current evidence, there is no basis for concern on the issue of using silicofluorides in fluoridated water supply systems.
Mr Reeves concluded by refuting the claim that the fluoride from natural sources, like calcium fluoride, is better than fluorides added ‘artificially’, such as from the fluoride chemicals.
Dr Evans was executive editor and project director of the Surgeon General’s Report on Oral Health and is currently leading initiatives responsive to the report’s “framework for action”. He is based at the National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, United States of America.
Dr Caswell Evans delivered a presentation entitled “Fluoridation – Recent Developments in the U.S.”
Background: Oral Health in the United States
Dr Evans initially provided some background information on the oral health status of the American population, with particular reference to the area of oral health inequalities, which was published in the recent Surgeon General’s Report. (30) Dr Evans was Executive Editor and Project Director of this report.
- More than 51 million school hours are lost each year to dental related illness.
- Poor children suffer nearly 12 times more restricted activity days than children from higher income families.
- For each child without medical insurance, there are at least 2.6 children without dental insurance. Uninsured children are 2.5 times less likely than insured children to receive dental care.
- Dental caries is the single most common chronic childhood disease - 5 times more common than asthma and 7 times more common than hay fever.
- Poor children suffer twice as much dental caries as their more affluent peers, and their disease is more likely to be untreated.
- Over 50% of 5 to 9 year old children have at least one cavity or filling, and that proportion increases to 78% among 17 year olds.
- Tobacco related oral lesions are prevalent in adolescents who currently use smokeless tobacco (they chew tobacco).
- Unintentional and intentional injuries commonly affect craniofacial tissues.
Today 25% of children aged 5 to 17 years in the U.S. experience 80% of the dental caries found in permanent teeth.
- Among low-income children, almost 50% of tooth decay remains untreated.
- Overall the prevalence of dental caries among 12 to 17 year olds has declined from 90% in 1971 – 1974 to 67% in 1988 to 1991. The severity, as measured by DMFT has declined fro 6.2 to 2.8 during this period.
- For every adult 19 years or older without medical insurance, there are three without dental insurance.
- Severe periodontal disease affects about 14% of adults aged 45 to 54 years.
- Twenty three percent of 65 to 74 year olds have severe periodontal disease.
- About 30% of adults 65 years and older are edentulous compared to 46% 20 years ago.
- Oral and pharyngeal cancers are diagnosed in about 30,000 Americans annually; 8,000 die from these diseases each year.
- US$60 Billion are spent annually on dental services, which includes approximately 500 million visits to dental offices.
U.S. Surgeon General’s Report on Oral Health
Dr Evans then spoke on the recent Surgeon General’s Report on Oral Health from which the above statistics were quoted. (30)
The Surgeon General is appointed by the U.S. president and ratified by Congress and serves a period, which overruns the presidential term by 2 years. The Surgeon General is an apolitical appointee and is not involved in policy-making decisions, but has the power to make recommendations.
Fifty reports have been produced in the history of the office (1964 to date), 25 of which have been related to tobacco and have had profound affect on tobacco usage. Of the remaining 25 reports, subjects have included problems or issues, which are either poorly understood or were inadequately addressed in the past.
The realisation that oral health can have a significant impact on the overall health and well-being of the nation’s population led the Office of the Surgeon General, with the approval of the Secretary of Health and Human Services, to commission a report, published in 2000, entitled ‘Oral Health in America’. www.nidcr.nih.gov/sgr/oralhealth.asp.
Recognising the gains that have been made in disease prevention while acknowledging that there are populations that suffer disproportionately from oral health problems, the Secretary asked that the report “define, describe, and evaluate the interaction between oral health and health and well-being, through the life span in the context of changes in society”.
The report centred on five major questions:
- What is oral health?
- What is the status of oral health in America?
- What is the relationship between oral health and general health and well-being?
- How is oral health promoted and maintained and how are oral diseases prevented?
- What are the needs and opportunities to enhance oral health?
The themes of the report were as follows:
- Oral health includes healthy teeth, but means much more
- You cannot be healthy without oral health
- Safe and effective disease prevention measures exist that everyone can adopt to improve oral health and prevent disease
- Risk factors common to many diseases and conditions, such as tobacco and alcohol use and poor dietary practices, also affect craniofacial health.
Dr Evans then outlined the major findings of the report:
Oral diseases and disorders in and of themselves affect health and well being throughout life
Range from birth defects to chronic disabling conditions and cancer
Interfere with vital functions: breathing, eating, swallowing and speaking
Cause other health problems
Undermine social interactions, self-esteem
Incur fiscal and social costs
The mouth reflects general health and well-being
The mouth is a readily accessible and visible part of the body and provides health care and individuals with a window on their general health status.
Portal as well as a barrier to infections
Saliva, buccal cells and other oral components have additional diagnostic potential
Oral diseases and conditions are associated with other health problems
Adverse pregnancy outcomes
Lifestyle behaviours that affect general health, such as tobacco use, excessive alcohol use and poor dietary choices, affect oral and craniofacial health as well.
These individual behaviours are associated with increased risk for craniofacial birth defects, oral and pharyngeal cancers, periodontal disease, dental caries, and candidiasis among other health problems. All health care providers can play a role in promoting healthy lifestyles by incorporating tobacco cessation programmes, nutritional counselling, and other health promotion efforts into their practices.
There are safe and effective measures to prevent the most common dental diseases – dental caries and periodontal diseases.
Community water fluoridation
Other fluoride measures and dental sealants
Personal oral hygiene and use of a fluoride dentrifice
Cessation / prevention of tobacco use.
There are profound and consequential oral health disparities within the American population
Disparities relate to income, age, gender, race / ethnicity
Disparities due to lack of information or access to preventive measures
More information is needed to improve America’s oral health and eliminate disparities.
Scientific research is key to further reduction in the burden of disease and disorders that affect the face, mouth and teeth.
The report called for the development of a National Oral Health Plan, in an effort to eliminate health disparities and improve quality of life for all Americans. Such a plan would include collaborations among individuals, health care providers, communities, and policy-makers.
National Oral Health Plan
The National Oral Health Plan has the following principal components:
- Change perceptions of the public, policy makers and health care providers regarding oral health and disease so that oral health becomes an accepted component of general health.
This will involve enhancing the public’s understanding of the meaning of oral health and the relationship of the mouth to the rest of the body. Raising awareness of oral health among legislators and public officials at all levels of government is essential to creating effective public policy to improve America’s oral health. The inclusion of oral health examination as part of a general medical examination, advising patients in matters of diet and tobacco cessation, and referring patients to oral health practitioners for care prior to medical or surgical treatments that can damage oral tissues, such as cancer chemotherapy or radiation to the head and neck.
- Remove known barriers between people and oral health services. Data collected indicated that lack of dental insurance, private or public, is one of several impediments to obtaining oral health care and accounts in part for the generally poorer oral health of those who live at or near the poverty line, lack health insurance or lose their insurance upon retirement.
- Use public- private partnerships to improve the oral health of those who still suffer disproportionately from oral disease. The collective and complementary talents of public health agencies, private industry, social services organisations, educators, health care providers, researchers, the media, community leaders,voluntary health organisations and consumers groups, and concerned citizens are vital if America is not just to reduce, but to eliminate, health disparities.
- Accelerate the building of the science and evidence base and apply science effectively to improve oral health.
- Build effective health infrastructure that meets the oral health needs of all Americans and integrates oral health effectively into overall health.
Following publication of this report, actions to achieve the above objectives have been undertaken by a number of organisations: American Dental Education Association, Oral Health America, American Association of Women Dentists, American Dental Trade Association, National Governor’s Association, Dental Manufacturers of America, Advocacy and community groups, Proctor and Gamble,
Partnership for Prevention, Colgate Palmolive, Grantmakers in Health, America College of Dentists, Friends of the Surgeon General’s Report on Oral Health, National Association of Dental Plans, National Dental Association, Hispanic Dental Association as well as many others many others.
Dr Evans then spoke about the methods, which will be employed to achieve the plans laid out above.
He referred to the work being undertaken in compiling the Guide to Community Preventive Services: Systematic Reviews and Evidence-Based Recommendations which will be published in late 2001.
This guide aims to improve public health practice by increasing the use of effective interventions. The Guide summarises what is known regarding the effectiveness of selected population-based interventions and information about additional benefits and harms of the interventions. The evidence is gleaned from systematic reviews, co-ordinated by CDC scientists, and an independent Task Force will determine recommendations. This Task Force is 15-member, non-federal and independent panels of experts. The day-to-day work of the Task Force is co-ordinated by an interdisciplinary full-time staff of scientists and administrators made available by the Centre for Disease Control and Prevention. For each chapter, a staff scientist co-ordinates a multidisciplinary team, with input from subject matter consultants.
Dr Evans dealt briefly with the methods employed in the systematic review:
o Develop a conceptual framework
o Search for and retrieve evidence
o Rate quality of evidence
o Summarise evidence
o Translate strength of evidence into recommendations.
This guide is currently addressing a list of six risk behaviours related to the largest burden of disease: tobacco use, alcohol abuse and misuse, other substance abuse, nutrition, physical activity and sexual behaviour. Eight reviews will address how to reduce disease, injury and impairment. As various chapters are completed they are published as entities in themselves. The chapter on oral health will be highlighted in the CDC publication Morbidity and Mortality Weekly Report in the next few months.
Reviews of a number of interventions for improved oral health have at this stage been completed and recommendations have been made which range from ‘recommends strongly’to ‘unable to recommend to make recommendations based on the available evidence’focussed on:
School based sealant delivery programmes: Review of this intervention is complete and is strongly recommended.
Community-wide sealant promotion interventions: Review of this intervention is complete, but insufficient evidence was available to make a recommendation.
Community water fluoridation: Review of this intervention is complete and is strongly recommended.
More information on the Community Guide may be obtained via the internet: www.thecommunityguide.org.
The Community Guide is part of a family of federal initiatives, and will complement the Guide to Clinical Preventive Services, which aims to promote evidence-based prevention for individuals. (31)
Dr Evans then referred to Healthy People 2010, a set of health objectives for the U.S. nation to achieve over the first decade of the 21stcentury. Healthy People 2010 builds on initiatives pursued over the past two decades. The 1979 Surgeon General’s Report along with Health People 2000 established national health objectives and served as the basis for the development of State and community plans. In total there are 467 health objectives and 20 oral health objectives. www.health.gov/healthypeople.
A number of oral health objectives are listed below:
o Reduce the proportion of children and adolescents who have dental caries experience in their primary or permanent teeth
o Reduce the proportion of children, adolescents, and adults with untreated dental decay.
o Increase the proportion of adults who have never had a permanent tooth extracted because of dental caries or periodontal disease.
o Reduce the proportion of older adults who have had all their natural teeth extracted.
o Reduce periodontal disease
o Increase the proportion of oral and pharyngeal cancers detected at the earliest stage.
o Increase the proportion of adults who, in the past 12 months, report having had an examination to detect oral and pharyngeal cancers.
o Increase the proportion of children who have received dental sealants on their molar teeth.
o Increase the proportion of the U.S. population served by community water systems with optimally fluoridated water; An increase from 62% to 75% (21% improvement) by the year 2010: this would add 30 million more people served by approximately 1000 community water systems.
o Increase the proportion of children and adults who use the oral health care system each year.
The objectives are reviewed and updated every 10 years; some objectives are removed, for example, where effective databases are unavailable. In the area of oral health the majority of objectives have good databases, and so the oral health objectives have been retained.
At this stage in his presentation Dr Evans spoke about water fluoridation in the United States and made the following points.
The United States Centre for Disease Control and Prevention (CDC) has recognised water fluoridation as one of the great public health achievements of the 20thcentury.
The United States Public Health Service (USPHS) recommends 0.7 to 1.2 ppm, depending on the mean maximum daily air temperature of the area.
He referred to the various studies, which were performed following the initiation of water fluoridation in Grand Rapids, Michigan in 1945. In 95 studies conducted between 1945 and 1978 the caries reduction rate was found to be 40 – 50% in primary teeth and 50 – 60% in permanent teeth.
He referred to comparative studies between fluoridated and non-fluoridated communities in the U.S., Australia, Britain, Canada, Ireland and New Zealand.
Water Fluoridation in the United States
The fluoridation status in the U.S. was then discussed. Of the 50 largest cities practically all are fluoridated. Legislation requiring a number of cities to fluoridate the water has been passed in a number of states and this will result in increased numbers.
Data from 1992, showed that 62% of the populations served by public water supplies, consumed optimally fluoridated water. Dr Evans referred to the fact that more up to date data would show a larger percentage and that this would be published in the awaited CDC document on fluoridation. (32)
Figures in this document have subsequently revealed that in 2000, a total of 38 states and the District of Columbia provided access to fluoridated public water supplies to over 50% of their population.
Dr Evans concluded his presentation by relating the sequence of events that led to the enactment of California’s Mandatory Fluoridation Act in 1995.
Oral Health surveys had shown that children in California had significantly poorer oral health than children in states where public water supplies were fluoridated. A congress member, Ms Jackie Spears, a health advocate, was instrumental in passing legislation (AB733) to mandate water fluoridation in cities with populations in excess of 200,000, when money was available.
At this time the privatisation of a medical insurance company resulted in the state receiving a large sum of money, which it was required by law to spend on public health initiatives. Under U.S. law a company, which had provided a public service, could not retain any profits from public earnings when it was privatised.
Since the enactment of the Californian legislation, a number of other cities have taken action to fluoridate their public water supplies. These include Dover-Foxcroft, Maine, Escambia County, Florida, Salt Lake City, Utah, San Antonio, Texas, Las Vegas Nevada and Gilbert,Arizona.
Dr Evans pointed out that public support for water fluoridation in California was in part due to the fact that the very mobile American public (the average U.S. citizen moves every five years) viewed fluoride in the water as an added value to life, and having seen the benefits elsewhere, wanted these benefits when they moved to California.
He also made the point that no state has stopped water fluoridation, but that a number of small communities have done so.
On why the U.S. opted for water fluoridation rather than other delivery methods, Dr Evans stated that in the U.S. where there is no universal health care system, the delivery of fluoride by other methods in an effective manner was not possible.