CASE STUDY FOR THE 4TH YEAR COURSE IN ECOSYSTEM HEALTH
DENTAL FLUOROSIS (under development)

MEDICAL - BACKGROUND

The following questions highlight specific areas of knowledge, with which you may already be familiar; however, you may want to review the material under each question to ensure you have an accurate and complete understanding. A clear understanding of this material is necessary in order to discuss and comprehend this case study.

What is Fluorosis?

What about Fluoride Deficiency?

What is the natural history of Fluorosis?

What are common sources of Fluoride?

How does Fluoride enter the human body?

What is the epidemiology of Fluorosis?

What is Fluorosis?

In the broadest sense, the term "Fluorosis" describes a state of toxicity of the trace element, Fluorine (commonly referred to in its ionic state as Fluoride) within an organism. Fluorosis is not limited to humans, and can affect any aspect of the ecosystem.

Click here for a brief review of Fluorine chemistry.

Humans appear to vary considerably with respect to their susceptibility to Fluorosis. As a general guideline, prolonged total Fluoride intake exceeding 1.0 mg/day can produce clinical signs of Fluorosis in adults.

Fluoride status in humans is governed by a variety of factors that cover a wide range of Medical, Environmental, Economic and Socio-political issues. It is not possible to effectively deal with Fluorosis within your patient community without understanding all aspects of this problem.

Generally speaking, human Fluoride toxicity will manifest as any combination of;

• Dental Fluorosis: (link to pictures) the most obvious and easily diagnosed form of Fluorosis by a characteristic bilateral white mottling of the dentition. Dental Fluorosis is usually caused by over-exposure to Fluoride when the dental enamel is actively mineralizing during early childhood.
• Skeletal Fluorosis: (link to pictures) involves abnormal mineralization of bone and soft tissues and/or the distruption of normal activity of the osteocytes. For this reason, Skeletal Fluorosis often mimics "generic" osteoarthritis and/or osteoporosis in relatively young adults.
• Systemic Fluorosis: due to the chemical nature of Fluoride and its action(s) within mammalian systems which are not limited to teeth and bone, Fluoride toxicity may potentially be linked to every major multiple cause ailment of the 20th century from cancer to Attention Deficit Disorder.

Fluoride toxicity may be acute or chronic, with affects ranging from cosmetic damage, to disability and even death. With the exception of Dental Fluorosis, Fluoride-related illness is often attributed to other diseases or syndromes (i.e. osteoarthritis for Skeletal Fluorosis, cardiovascular failure for death by acute Fluoride poisoning) making Fluorosis in itself very difficult to track epidemiologically in the absence of an ecosystem health framework.

What about Fluoride Deficiency?

You will not find Hypofluoremia in Taber's Cyclopedic Medical Dictionary simply because, strictly speaking, there is no such thing as human Fluoride Deficiency. Fluoride is ubiquitous in food, water, air, and most tissues of the human body, and no physiological dysfunction results from having a "theoretically impossible" Fluoride intake of zero.

The aim of artificial fluoridation of drinking water in some Western World countries as a public health measure is the prevention of dental caries. It is important to understand that dental caries are not caused by a lack of Fluoride. Rather, dental caries are caused by the presence of oral bacteria that thrive on the simple sugars that have become a prominent part of the standard American diet. The chemical action of Fluoride on teeth is to resist dissolution of the enamel by acid-producing oral bacteria.

A Medical Analogy: think Fluoride as sunscreen for your teeth...

The relationship between Fluoride and dental caries is somewhat analogous to the relationship between sunscreens containing para-aminobenzoic acid (PABA) and skin cancer. Like Fluoride, sunscreens containing PABA can sometimes have adverse effects, like allergic dermatitis, although they do block the sun's harmful ultra-violet (UV) rays that can cause skin cancer. However, it cannot be correctly said that failing to use sunscreen causes skin cancer. Rather, exposure to UV rays induces the mutations in dermal cells that lead to skin cancer. If you have suitable skin pigmentation or you don't go out in the sun during periods of peak UV intensity and wear adequate protective clothing during prolonged sun exposure, then you have little need of sunscreens containing PABA - especially if you want to avoid allergic dermatitis.

So while there is no such thing as an Absolute Fluoride Deficiency, the trend towards "Global Westernization" and the widespread adoption of the standard American diet without concomitant improvements in oral hygiene practices or access to professional dental care means that increasing numbers of people can be said to suffer from a Relative Fluoride Deficiency.

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What is the natural history of Fluorosis in humans?

There has likely been Fluorosis in humans for as long as there have been humans. However, evidence from the fields of archeology, physical anthropology and forensic geology suggest that Fluorosis in ancient peoples was limited to those living in very specialized environments, namely;

• Active Volcanic Areas: where some types of volcanic eruptions are known to emit large quantities of Fluorine in the forms of HF gas and elemental Fluoride adherent to the surface of fine-fraction volcanic atmospheric particulates called tephra. If it happens to rain during the eruption, the HF gas will be "scrubbed" from the atmosphere by the meteoric water and then introduced into the nearby surface and groundwaters. When the tephra finally settles to the surface, the Fluoride component of the tephra particle will rapidly dissolve in surface water bodies (i.e. oceans, lakes, ponds, rivers, streams, etc.) or be leached into the groundwater with the first rain. Grazing animals who ingest ash-covered forage or drink Fluoride-enriched surface water are often the most affected by volcanic Fluoride emissions.
• Coastal Areas: where the human population consumes large quantities of marine plants and animals as dietary staples and inhales Fluoride-rich water vapour. Salt water contains relatively large amounts of dissolved Fluoride (1.3 mg/L, (Pais, 1997)) which is imparted to marine plants and animals or which may enter the blood stream through respiration. Also, bones contain up to 3 times the amount of Fluoride as soft tissues, and so eating whole fish, especially small fish like sardines and anchovies, results in a greater Fluoride intake.
• Arid Areas: with access to only deep groundwater sources. People who live in arid climates will obviously consume more water to avoid the consequences of dehydration. Surface water sources are often not able to sustain habitation in these regions. The population therefore relies on the deeper, "older" groundwater which typically has a higher mineral content. (reference)

From the late 18th century onwards, the history of Fluorosis in the ecosystem becomes less and less "natural" due primarily to radically altered human activities. Prior to the Industrial Revolution, incidence of Fluorosis outside of the previously mentioned specialized environments appears to have been scarce.

Some Highlights From the Last 330 Years of Fluorosis

• 1529 Georgius Agricola describes the use of Fluoride minerals as a flux.
• 1670 Scheele, Davy, Gay-Lussac, Lavoisier, and Thenard experiment with Hydrofluoric acid with some experiments ending in tragedy.
• 1850's crop damage attributed to iron and copper industrial Fluoride emissions in England and Germany.
• 1886 after 74 years of continuous effort by chemists, Moisson isolates the element Fluorine.
• early 1900's first lawsuits in North America filed for poisoned peach crop downwind from Fluoride-related industries.
• 1916 G.V. Black and F.S. McKay present study associating tooth mottling (Dental Fluorosis) with Fluoride.
• 1920's deep well drilling technology begins to to become widely available in North America.
• 1931 H.T. Dean, DDS heads to the US Midwest to investigate reports of "Colorado Brown Stain" and "Texas Teeth" associated with naturally Fluoridated drinking water.
• 1933 sixty people die in Belgium's Meuse Valley from industrial Fluoride emissions.
• 1939 based on Dean's findings, and less than 8 years of clinical trials on lab rats, the Aluminium Company of America's (ALCOA) head scientist recommends artificially Fluoridating public water supplies with Aluminum processing waste products as a means of preventing dental caries in humans.
• 1944 duPont's New Jersey plant is sued $US 400,000 for damages to local peach crops due to emissions associated with Manhattan Project activities that required massive amounts of Fluoride for Unranium refining.
• 1939-1945 World War II Military-Industrial Complex is in high gear production of Fluoride-related materials.
• 1945 first North American community institutes artificial water Fluoridation in Brantford, Ontario.
• 1948 "Donora Death Fog" kills 20 people around the US Steel Company and Donora Zinc Works facilities.
• 1950 eighty nine US cities are implementing artificial water Fluoridation.
• 1950/60's UNICEF engaged in extensive deep well drilling operations in developing countries to relieve water stress.
• 1962-1968 Fluoridated toothpaste becomes widely available in North America.
• 1970 US Department of Agriculture states that "airborne Fluoride caused more worldwide damage to domestic animals than any other pollutant"
• 1980 residents of St. Regis Akwesasne First Nations Reserve awarded $US 650,000 for damages to crops and livestock from nearby Reynold's Metals Co. and ALCOA Fluoride emissions.
• 1984 thousands die in Bhopal, India likely as a result of accidental Fluoride emissions and other contaminants from the Union Carbide oil refinery.
• 1993 three patients die and five suffer from symptoms of toxicity when Fluoridated water is used during kidney dialysis treatment in a Chicago, IL hospital.
• 1999 artificial municipal water fluoridation declared one of the most significant achievements in public health of the last century by the US Center for Disease Control.
• 2000 "A Civil Action" lawyer, Jan Schlichtmann, takes on Ormet Primary Aluminum Corporation for public smear campaign against Ohio Supreme Court Justice A.R. Resnick who had found Ormet responsible for Fluoride contamination of local groundwaters.
• On the Brink of the 21st Century: incidence of all forms of Fluorosis is now steeply on the rise in the Western World and is recognized as a major threat to public and ecosystem health in the Developing World. Dentists are devoting more of their treatment time to Dental Fluorosis, and doctors are seeing increasing numbers of patients suffering from what may be Skeletal and/or Systemic Fluorosis.

What are common sources of Fluoride?

While Fluoride has always been a natural part of our ecosystem, unprecedented quantities of crustal Fluoride are now being accessed and liberated into the environment. We are often oblivious to the variety of geogenic and anthropogenic sources of Fluoride that we are exposed to on a daily basis. Most of these sources are currently some combination of;

• Unregulated: Example: the Fluoride content of bottled waters,
• Uncontrollable: Example: the Fluoride emissions from an erupting volcano, and
• Undercover: Example: the Fluoride in agriculture, food and drugs.

The irony of Fluorosis is that life as we know it would probably not be possible were it not for Fluoride. The truth of this statement is evident in a popular saying from the Earth Sciences,

"If it cannot be grown, it must be mined."

Fluoride plays a prominant role not only in agriculture and mining, but also in energy production and further processing. Take a look around you. A surprising number of articles in your immediate environment either contain Fluoride or were made possible by Fluoride technology somewhere along the line.

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Common Sources of Fluoride for Humans

Water: varies considerably with respect to Fluoride (F) content, as do human rates of consumption. Water is also a ubiquitous substance, and acts as a "trap" for much of the Fluoride in the surrounding environment. Water may be further categorized as;

Oral Medications: Many recent advances in science and medicine revolve around the pharmaceutical industry. Consequently, access to and use of oral medications has increased significantly for individuals of high socio-economic status, especially in affluent countries. While an undetermined portion of the F in drugs is retained in the body, the rest of the F in whole or decomposed oral medications will eventually be "flushed" into municipal sewage or septic tank water.

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Food and Beverages: also vary considerably with respect to F content, partially owing to the chemical characteristics of the water used in further processing, known as the Fluoride Halo Effect (ex. beer, sodas, canned foods). Certain foods and beverages, like sea food and teas, contain high concentrations of F "naturally" because of the environment in which they are grown. Food additives, be they intentional or accidental, like salt and soil may also contain highly variable amounts of F depending on environmental factors. Commercially sold bottled waters sometimes even exceed the World Health Organization's maximul acceptable concentration (MAC) for F due the natural geochemical characteristics of the aquifer.

• Range of F Concentration:

Dental Treatments: with the possible exception of toothpaste, these are typically available to residents of affluent countries or to individuals of high socio-economic status. The possibility of misuse is obviously greater for the do-it-yourself, over-the-counter dental treatments than for professionally supervised F treatments in school children by the Public Health department or the more costly professional services of a dentist or dental hygienist.

Volcanoes: release mass amounts of crustal F in the form of HF gas and F-rich tephra into the atmosphere. This F is mainly incorporated into the biosphere by;

1. dissolution/leaching into local water sources,
2. inspiration by lunged organisms,
3. ingestion by grazing animals, and
4. absorption/respiration by vegetation.

Each volcanic eruption is unique, and not all volcanoes represent potential F hazards. While volcanologists and earth scientists are understandably primarily concerned about more the immediate and deleterious effects of any given eruption, they are also good sources information regarding the F emissions of a particular volcano.

• Range of F Concentration:

Industry: F compounds are the flux of choice for most metal refining processes (ex. Copper, Steel, Aluminum) as well as for many activities surrounding the production of glass, ceramics, plastics (including Teflon and Goretex), and a host of useful chemicals like lubricants, solvents, refrigerants, and propellants. "Proper" disposal (i.e. to be made unavailable to the environment in non-toxic concentrations) of extremely corrosive and very water-soluble liquid F waste products is difficult and expensive, and hence also very uncommon. Also, incorporation of industrial atmospheric F contamination into the biosphere is very similar to the F emissions associated with volcanic activity. The important differences being that the lower-volume industrial F emissions are continous rather than sporatic, and are typically released into densely (versus sparsely) populated areas. Surface "slag" heaps produced by the mining industry sometimes also contain solid, but soluble, F-bearing minerals that represent a potential point source for surface and groundwater contamination.

• Range of F Concentration:

Extraterrestrial: sources of F are perhaps the least understood in terms of F concentration and impact on Fluorosis. However, it stands to reason that the Earth's continuous bombardment with F-containing "space junk" should result in some gradual accumulation of F in the biosphere.

• Range of F Concentration:

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Agriculture: many commonly-used agricultural pestiticides, including rat poisons, and fertilizers both contain significant quantities of Fluoride and are responsible for local Fluoride pollution near the processing plants. The more obvious destination of agricultural F is into food and beverage products, but incorporation into drinking water sources is perhaps less obvious. Not only is it suspected that the F associated with the application of some phosphate fertilizers and cryolite-based insecticides may "leach" into surface waters and shallow groundwaters, but by-products of the phosphate fertilizer industry are the primary source of "artificial" F for many municipal water fluoridation programs.

• Range of F Concentration:

Energy Production: as with a volcanic eruption, large quantities of crustal Fluoride are released into the environment by the combustion of Fluoride-rich coal in the form of HF gas and adherent to fine-grained flyash particles. Fossil fuels are the primary energy source for the majority of Developing World. The mineral or ash content is significantly higher in Indian and Chinese coals (up to 50% ash and halogen-rich) as compared with most Western World coals (15% ash and halogen-poor). The emissions control devices of most coal smelters used in these densely populated, rapidly industrializing, and energy-hungry nations are not designed for these high-ash and Fluoride-rich coals. Leachate from flyash ponds and halogen-rich coal heaps may contribute significant concentrations of F to local surface and groundwaters. HF is an important chemical in oil refining, and large quantities of Fluoride are also required as a flux in the processing of Uranium for atomic energy and nuclear weapons. This is one reason why artificial municipal water fluoridation was not actually possible until after the military-industrial episode of World War II. The large quantities of soluble Fluoride required simply were not yet available.

• Range of F Concentration:

A Summary of the Common Sources of Fluoride

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How does Fluoride enter the human body?

While Fluoride is truly ubiquitous, it is not always bioavailable. Insofar as Fluorosis in humans is concerned, there are essentially four ways for gaseous, liquid, or solid forms of Fluoride to enter the body, although each eventually involves Absorption at some level of physiology.

How Fluoride Enters the Human Body

1. Imbibition: pertains to the natural or "artificial" Fluoride in drinking water and in beverages that have a high water content (ex. colas, teas, coffee, juices, alcoholic beverages, etc.).
2. Ingestion: refers to the Fluoride in foods, vitamins, drugs, and perhaps toothpaste or mouth rinses, and the Fluoride in any dusts and soils covering anything we put into our mouths and swallow.
3. Inhalation: includes HF gas as well as Fluoride-bearing fine-fraction particulate matter that comes in contact in mucous membranes of the respiratory tract (ex. dust, flyash, and tephra).
4. Dermal Absorption: usually involves liquid Fluoride compounds that are absorbed through the skin, the eyes and possibly the mouth.

What is the epidemiology of Fluorosis?

Confounding signs and symptoms, multiple sources of Fluoride, and a variety of predisposing physiological factors make modern Fluorosis nearly impossible to "track" epidemiologically. However, as was suggested in the section pertaining to the natural history of Fluorosis in humans, the occurence and distribution of human Fluoride toxicity has changed significantly in the last 150 years, more specifically since the onset of Industrial Revolution.

Fluorosis: Where in the World?

Prior to 1850, one might expect to find Geogenic-source Fluorosis in countries whose bulk of population resided in one or more of the three previously mentioned specialized environments. For example, we could have predicted the occurence of Fluorosis in;

• Japan: active volcanic area, coastal area
• Bahrain: arid area
• Iceland: active volcanic area, coastal area
• Kenya: volcanic area, coastal area, arid area

Fluorosis is particularly devastating in the many cultures where there is an emphasis on the performance of heavy physical labour, where access to healthcare is severely limited, and where nutritional status is often precarious. Although Industrialization was meant to improve the circumstances that determine the metabolic status of people groups in the Developing World, it appears as if the Fluoride status of the general population has continued to deteriorate, perhaps under the additional burden of exogenous sources of Fluoride.

Susceptibility to Fluorosis: You are what you eat - AND what your metabolic state says you are!

But there appears to be more to the epidemiology of Fluorosis than the state of the environment alone. Humans appear to vary considerably with respect to their susceptibility to the Fluoride in their immediate environment, depending primarily on their metabolic and/or nutritional status.

Essentially, the metabolic argument for epidemiology of Fluorosis is based on the chemistry of the Fluoride ion, which largely determines its bioavailability in mammals. Many theses could be written on the subject, but the important things to bear in mind are,

1. Fluoride reactions are strongly pH-dependent, being more "available" in acidic conditions,
2. Fluoride has a great affinity for positively-charged ions, and
3. Most Fluoride compounds are soluble in water to some degree or another.

Based then on metabolic status, we would expect to see endemic Fluorosis in populations who are exposed to high Fluoride concentrations in their environment and who;

1. are chronically malnourished or undernourished (i.e. in a state of metabolic acidosis)
2. are in a state of fasting while consuming Fluoride-rich water or beverages
3. consume a cation (namely Calcium) deficient diet
4. are otherwise metabolically-challenged (ex. suffer from kidney disease)

Again, outside of the laboratory, it is very difficult to discern whether Fluorosis is the cause or the result of metabolic dysfunction, but it is clear why people in China, India, and many African, Latin American, and Middle Eastern countries have been struggling with Fluorosis for a very long time.

Fluorosis and Children: A Special At Risk Population

Children are worth special mention with respect to Fluorosis. With less body mass and decreased overall metabolic capacity, they are particularly susceptible to Fluoride toxicity as they undergo critical stages of rapid cell reproduction and differentiation. UNICEF attributes Fluorosis in 20 mostly Developing World countries around the globe to toxic amounts of Fluoride, primarily in drinking water. The United Nations acknowledges Fluorosis as a major threat to public health in those demographically "youth-full" countries where the majority of the world's population lives.

Fluorosis: NIMBY, Not In My Backyard?

While the most densely populated corners of the globe focus their attention on battling physically debilitating Skeletal and Systemic Fluorosis, the Western World appears preoccupied with the chiefly cosmetic concern of Dental Fluorosis, documenting recent increases of up to 45% in the incidence of mottled teeth in North American children.

Discussion Question: How does globalization affect the "natural" history of human Fluorosis? Also consider the effects of large wars and global conflict on Fluoride issues.

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MEDICAL - DIAGNOSIS OF PROBLEM

• What are normal Fluoride concentrations in body tissues and fluids?
• What are the clinical signs of Fluorosis?
• What are the symptoms of Fluorosis?
• What other diseases are related to Fluorosis?
  
  

What are normal Fluoride concentrations in body tissues and fluids?

The effects of excessive Fluoride intake on the human body are not limited to bones and teeth. Therefore, having observed clinical signs of any one of Dental, Skeletal, or Systemic Fluorosis, the physician or dentist should be on the look-out for other manifestations of Fluoride toxicity in their patients.

Clinical Signs of Fluorosis;

1. Mottled Dentition:

Click here to see pictures of Dental Fluorosis associated with different concentrations of Fluoride in drinking water.

2. Abnormal Tissue Mineralization:

Click here to view a diagnostic protocol for Skeletal Fluorosis developed by Indian healthcare providers.

3. Elevated Body Fluid Fluoride Concentrations:

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What are the symptoms of Fluorosis?

Though apparently vague and non-specific, most of the symptoms of Fluoride toxicity point towards some kind of profound metabolic dysfunction, and are strikingly similar to the symptoms of Hypothyroidism.

Symptoms of Fluorosis

1. Learning Disorders/Difficulty Concentrating/Incoherence/Memory Loss/Confusion
2. Body Temperature Disturbances/Cold Shivers
3. Chest Pains
4. Heart Palpitations
5. Depression
6. Dizziness/Vertigo
7. Dyspepsia
8. Excessive Sleepiness/Fatigue
9. Headaches/Migraines
10. Joint Pains
11. Nausea
12. Restlessness
13. Sensitivity to Light
14. Shortness of Breath
15. Difficulties Swallowing
16. Thirst
17. Tinnitus
18. Visual Disturbances

Major Related Diagnoses: Alzheimer's Disease/demyelinizing diseases, anemia, arthritis, breast cancer, carpal tunnel syndrome, decrease in testosterone/spermatogenesis, altered vas deferens/testicular growth, decreased dental arch, dental crowding, delayed tooth eruption, diabetes insipidus, diarrhea, Down Syndrome, early onset of puberty, eosinophilia, eye/ear/nose disorders, fever, gastro-intestinal disturbances, gingivitis, heart disorders, hypertension, hypoplasia, hypothyroidism/thyroid cancer, kidney dysfunction, osteosarcoma, low birth weight, candidiasis, multiple sclerosis, oral squamous cell carcinoma, Parkinson's Disease, seizures, slurred speech, skin irritations, ankylosing spondylitis, telangiectasia, thrombosis, ulcerative colitis, uterine cancer, vaginal bleeding, weak pulse.

What other diseases are related to Fluorosis?

In answer to the question, "So what brings you into the clinic today?", you are not likely to hear the answer "Fluorosis" from many of your patients or their guardians, even though further investigation may reveal that Fluoride toxicity is indeed the reason for their visit.

Fluorosis is notoriously difficult to nail down with a diagnosis; however, it is a helpful practice to consider it a Fluorosis Purple Flag (as opposed to a red flag) in cases where;

1. the patient has consumed drinking water containing more than 1.5 mg/l over an extended period (especially during early childhood),
2. the patient has resided close to a possible point source of natural or anthropogenic F pollution during their lifetime (including in utero), and
3. the patient is currently complaining of, or there is a documented medical history of any combination of,

Discussion Question: Create a set of Clinial Pearls that would facilitate a rapid and accurate diagnosis of Fluorosis during an office visit.

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MEDICAL - TREATMENT

• What is the treatment for Dental Fluorosis?
  
  

What is the treatment for Dental Fluorosis?

ANSWER

Discussion Question: DISCUSSION QUESTION 3?

MEDICAL - PREVENTION

• How can Dental Fluorosis be prevented?
  

How can Dental Fluorosis be prevented?

ANSWER

Discussion Question: DISCUSSION QUESTION 4?

MEDICAL - CONNECTIONS

• How is Dental Fluorosis connected to environmental issues?
  
  
• How is Dental Fluorosis connected to economic issues?
  
  
• How is Dental Fluorosis connected to socio-political issues?
  

When you have visited each section in the Medical Module, please move on to the Environmental Module.

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• Overview
• Medical
  Background
  Diagnosis
  Treatment
  Prevention
  Connections
• Environmental
• Economic
• Socio-Political
• Summary