Health RISKS for you and
your family

The health risks presented in the brochure are fully supported by peer-reviewed scientific research.  Here we provide the full references for each of these health risks.

Fluoride Sensitivity:
As with many other substances, some people are acutely sensitive to fluoride (Feltman & Kosel, 1961), and will quickly become ill upon drinking fluoridated water (Grimbergen, 1974).

The full references are:

Feltman & Kosel (1961) used tablets with about 1 milligram of fluoride, which corresponds to the amount of fluoride in 1 litre of water fluoridated at 1 mg/L.  This study found that a range of symptoms occurred in about 1% of the patients.  The study used controls and was blinded, to rigorously establish that the reaction was to the fluoride.  Excerpts from the study are given below.

Three different sources of fluoride were used in this study. The tablets containing 1.0 mgm fluorine ion from CaF2; 1.2 mgm fluorine ion, from NaF and 0.825 mgm fluorine ion from Na2PO3F, each. These values were chosen so that each tablet would contain approximately the same amount of the ion and to supply an optimum amount of daily dietary supplement.

The measured doses of these salts were ingested by gravid women and by children through their eighth year of life, or during the periods of dental enamel formation. These tablets could be dissolved in the mouth, dissolved in any liquid or could be chewed, depending on the individual's preference or ability. One tablet daily was prescribed.

There was no selection of the patients included in this study, they were all patients utilizing the facilities of the hospital, coming from all walks of life and all ethnic groups. The controls were patients chosen at random from the above group who received no known supplemental fluoride. The water in the study area is fluoride free.

... One percent of our cases reacted adversely to the fluoride. By the use of placebos, it was definitely established that the fluoride and not the binder was the causative agent. These reactions, occurring in gravid women and in children of all ages in the study group affected the dermatologic, gastro-intestinal and neurological systems. Eczema, atopic dermatitis, urticaria, epigastric distress, emesis, and headache have all occurred with the use of fluoride and disappeared upon the use of placebo tablets, only to recur when the fluoride tablet was, unknowingly to the patient, given again. When adverse reactions occur, the therapy can be readily discontinued and the patient or parent advised of the fact that sensitivity exists and the element is to be avoided as much as possible.

Grimbergen (1974) selected patients who reported gastrointestinal symptoms on consumption of fluoridated water.  Water fluoridated at 1 mg/L was used, as well as distilled water as a control.  The study was double blinded, so neither the patients nor the physician knew which water was fluoridated until after the experiment was completed.  This experiment established that the fluoridated water caused the symptoms.  These are many more case studies finding similar results.

The most comprehensive report on fluoride toxicity is that released in 2006 by the United States National Research Council (NRC).  This report represents more than two years of work by a team of the world's foremost experts on fluoride toxicity, who reviewed hundreds of studies, and carefully examined their significance.  The NRC report examined the Feltman & Kosel and Grimbergen studies, and found no flaws.  The full reference for this report is:

The studies on fluoride sensitivity are discussed on page 269.  Water fluoridation is almost certainly making some people chronically ill.

Arsenic is a known carcinogen; there are no known safe levels for carcinogens.  Fluoride may cause bone cancer (osteosarcoma) among young men (Hoover, 1991; Cohn, 1992; NTP, 1990; Bassin, 2006).

Arsenic is the most common contaminant found in fluoridation chemicals, according to a 2008 report by the National Sanitation Foundation.  They calculated a mean contaminant level of 0.12 ppb, and a maximum contaminant level of 0.6 ppb.  Arsenic is known to cause cancer, and there is no known threshold below which arsenic does not cause cancer.  The incidence of cancer at lower concentrations can be estimated by assuming a linear dose-response relationship.  A National Research Council review in 1999 estimated that the lifetime risk of cancer due to arsenic at 50 ppb is about 1 in 100.  The full reference is:

The cancer risk due to arsenic in drinking water is discussed on page 8.

The National Resources Defense Council report in 2000 used the linear dose response relationship to estimate the cancer risk at 0.5 ppb as 1 in 10000.  This is the highest cancer risk the US Environmental Protection Agency usually allows in tap water.  They gave the risk estimates in the following table:

For comparison, the lifetime risk of cancer from 0.6 ppb arsenic (the highest level found by the National Sanitation Foundation) is about 1 in 8000, and the risk of cancer from 0.12 ppb arsenic (the average level) is about 1 in 40000.  With about 300 million people receiving fluoridated water, it can be expected that about 7000 cancers are caused by the arsenic in fluoridated water.

Water fluoridation is known to cause cancer due to the arsenic contamination in the fluoridation chemicals.  The fluoride itself is also a suspected carcinogen.  The full references for the studies given are:

Hoover RN, et al. (1991). Time trends for bone and joint cancers and osteosarcomas in the Surveillance, Epidemiology and End Results (SEER) Program. National Cancer Institute. In: Review of Fluoride: Benefits and Risks. US Public Health Service. pp F1 -F7.

Cohn PD. (1992). A Brief Report On The Association Of Drinking Water Fluoridation And The Incidence of Osteosarcoma Among Young Males. New Jersey Department of Health Environ. Health Service: 1-17.

National Toxicology Program [NTP] (1990). Toxicology and Carcinogenesis Studies of Sodium Fluoride in F344/N Rats and B6C3f1 Mice. Technical report Series No. 393. NIH Publ. No 91-2848. National Institute of Environmental Health Sciences, Research Triangle Park, N.C.

Bassin EB, Wypij D, Davis RB, Mittleman MA. (2006). Age-specific Fluoride Exposure in Drinking Water and Osteosarcoma (United States). Cancer Causes and Control 17: 421-428.

In 1977 the US Congress requested that the National Toxicology Program conduct an animal study to determine if fluoride causes cancer.  This study was conducted in the 1980s, and eventually published in 1990.  The National Toxicology Program (1990) found that there was a dose-dependent increase in osteosarcoma among male rats.  In response to this, the National Cancer Institute examined its National Cancer Registry data to determine if osteosarcoma rates are higher in fluoridated communities.  In the report (Hoover, 1991) the National Cancer Institute revealed that the incidence of osteosarcoma throughout the U.S. has increased at a greater rate among young boys in fluoridated areas versus unfluoridated areas.

Following this result, the New Jersey Department of Health conducted a study of osteosarcoma occurrence in Central New Jersey.  The study (Cohn, 1992) found a statistically significant relationship between fluoridation and osteosarcoma among males less than 20 years old.

The most recent study is that by a team of Harvard University scientists, led by Dr. Elise Bassin (Bassin, 2006).  This study found a five-fold increased risk of developing osteosarcoma among teenage boys exposed to fluoridated water at ages 6, 7, and 8.  The study is an extension of an analysis first completed by Bassin as a Harvard PhD thesis in 2001.

There was some controversy because this study was not made available for five years.  During that time, Bassin's PhD supervisor, Dr. Chester Douglass, claimed to have found no evidence that fluoride is associated with cancer.  Upon publication of Bassin's work, Douglass wrote a commentary that better data, still unpublished, contradict Bassin's results.  After four years this promised data is still not published.

There are published studies that do not show an association, but these studies have the crucial shortcoming that they do not test for a gender and age specific effect.  The research that has found an association between fluoride and osteosarcoma has examined young males.  If different ages and both genders are grouped together, then the association is obscured.

Thyroid Disruption: Thyroid function can be inhibited by fluoride (Galletti, 1958; Day, 1972; Jooste, 1999; Susheela, 2005; NRC, 2006).  Symptoms may include general fatigue, weakness, weight gain, muscle cramps, temperature sensitivity, constipation, difficulty concentrating, and abnormal menstrual cycles.

The full references are:

Galletti & Joyet (1958) found that a daily dose of just 2 to 10 mg of fluoride per day was enough to alleviate the condition of patients with overactive thyroid.  This is within the range of doses that many people living in fluoridated areas will ingest.  For example, consuming 3 litres of water per day of water fluoridated at 1 mg/L results in a dose of 3 mg per day.  This raises the concern is that fluoridated water results in underactive thyroid with people who would otherwise be healthy.

There have been many studies finding an association between goitre and water with excessive fluoride.  Goitre is caused by underactive thyroid (and can also be caused by overactive thyroid).  Day & Powell-Jackson (1972) performed an epidemiological study in Himalayan regions in Nepal, and found that goitre was strongly correlated with fluoride in the drinking water.  The fluoride levels in this study were below 1 mg/L, the level usually used for water fluoridation.

The study by Jooste (1999) found a strong correlation between fluoride in drinking water and goitre when examining children in South Africa.  This study examined regions with fluoride levels both below and above 1 mg/L.  Susheela et al. (2005) found disruptions in thyroid hormones in children exposed to excessive fluoride.

There are too many studies to list here, but these are extensively reviewed in the National Research Council report (2006).  For example, this report presents the results of the epidemiological studies on page 230.  The National Research Council report finds that drinking water with fluoride at 1 mg/L (the level usually used for water fluoridation) has an effect on the thyroid.  The exact quote is

Table 8-2 shows that several of the effects are associated with average or typical fluoride intakes of 0.05-0.1 mg/kg/day (0.03 with iodine deficiency), others with intakes of 0.15 mg/kg/day or higher. A comparison with Chapter 2 (Tables 2-13, 2-14, and 2-15) will show that the 0.03-0.1 mg/kg/day range will be reached by persons with average exposures at fluoride concentrations of 1-4 mg/L in drinking water, especially the children. The highest intakes (>0.1 mg/kg/d) will be reached by some individuals with high water intakes at 1 mg/L and by many or most individuals with high water intakes at 4 mg/L, as well as by young children with average exposures at 2 or 4 mg/L.

The symptoms of underactive thyroid are well known, and are listed, for example, in the Medline Medical Encyclopedia.

Reduced IQ: Many studies indicate fluoride exposure is correlated with lowered intelligence in children (Tang, 2008).  Fluoridation has been associated with increased lead levels (Masters & Coplan, 1999, 2000; Maas, 2007; Coplan, 2007; Sawan, 2010).  Lead is known to have effects on human intelligence and behaviour.

The full references are:

Tang Q-Q, Du J, Ma H-H, Jiang S-J, Zhou X-J. (2008). Fluoride and Children's Intelligence: A Meta-analysis. Biological Trace Element Research 126: 115-120.

Masters RD, Coplan M. (1999). Water treatment with Silicofluorides and Lead Toxicity. International Journal of Environmental Studies 56: 435-449.

Masters RD, Coplan MJ, Hone BT, Dykes JE. (2000). Association of silicofluoride treated water with elevated blood lead. Neurotoxicology 21(6): 1091-1099.

Coplan MJ, Patch SC, Masters RD, Bachman MS. (2007). Confirmation of and explanations for elevated blood lead and other disorders in children exposed to water disinfection and fluoridation chemicals. Neurotoxicology 28(5): 1032-1042.

Maas RP, Patch SC, Christian AM, Coplan MJ. (2007). Effects of fluoridation and disinfection agent combinations on lead leaching from leaded-brass parts. Neurotoxicology 28(5): 1023-1031.

Sawan RMM, et al. (2010). Fluoride increases lead concentrations in whole blood and in calcified tissues from lead-exposed rats. Toxicology 271: 21-26.

Tang et al. (2008) reviewed 16 studies, all of which indicated that fluoride in drinking water is associated with lower intelligence in children.  They concluded that children exposed to excessive fluoride are five times more likely to develop low IQ as compared to children that have not been exposed to excessive fluoride.

Most of these studies are for levels of fluoride in drinking water higher than that used in water fluoridation.  However, the difference is not large, and most studies are with levels of fluoride in drinking water no more than about 4 times that used in water fluoridation.  In comparison, for most contaminants, a safety factor of at least 10 is required between the level where adverse effects are observed and the levels allowed in drinking water.

A separate concern is that water fluoridation can result in higher lead levels of lead in children's blood.  Even small amounts of lead can reduce intelligence.  For example, see these studies:

Masters & Coplan (1999) used data from lead screening of over 280000 children in Massachusetts, and found that water fluoridated with silicofluorides is associated with significant increases in lead in children's blood.  The Masters, Coplan, Hone, & Dykes (2000) study examined data from 151225 children in the state of New York, and found that after controlling for other factors associated with higher blood lead, water fluoridated with silicofluorides was again associated with higher levels of lead in children's blood.

There are three possible causes of the higher levels of lead in blood associated with water fluoridation:
  1. The lead contamination in fluoridation chemicals.  The National Sanitation Foundation found a maximum level of lead due to fluoridation chemicals of 0.6 ppb (in comparison to an allowable concentration of 1.5 ppb).
  2. Silicofluorides used in water fluoridation can increase the rate of leaching of lead from plumbing fittings.  This was found by the Coplan et al. and Maas et al. studies in 2007.
  3. Silicofluorides can enhance the uptake of lead into the body.  For example, the Sawan et al. (2010) study found that fluoridation chemicals increased lead absorption in laboratory animals' bones, teeth and blood.

Dental Fluorosis:
Is a white/brown mottling of the teeth, and is a common side effect of water fluoridation.  More serious fluorosis damages tooth enamel; swallowing fluoride causes fluorosis (McDonagh, 2000; NRC, 2006).

The full references are:

The report by McDonagh et al. (2000) is one of the most prominent reviews on water fluoridation, and was performed by the National Health Service Centre for Reviews and Dissemination under instruction from the Chief Medical Officer of England's Department of Health.  It extensively reviewed the published scientific studies, and found that, at a fluoride level of 1 mg/L (the level usually used in water fluoridation), about 12.5% of exposed people would have fluorosis of aesthetic concern.  The exact quote from the results of the study is:

A dose-dependent increase in dental fluorosis was found. At a fluoride level of 1 ppm an estimated 12.5% (95% confidence interval 7.0% to 21.5%) of exposed people would have fluorosis that they would find aesthetically concerning.

The National Research Council (2006) also examined dental fluorosis, and concluded that dental fluorosis should be regarded as an adverse health effect, not a cosmetic effect (page 127).  They also noted that, at 1 mg/L, the exposure of infants and young children is at or above the Institute of Medicine (IOM) limits set to prevent dental fluorosis.  The exact quote is from page 129 of the report:

Furthermore, at EPA's current default drinking water intake rate, the exposure of infants (nursing and non-nursing) and children 1-2 years old would be at or above the IOM limits at a fluoride concentration of 1 mg/L (Table 2-13).

Skeletal Fluorosis:
About half of ingested fluoride is deposited in bones (WHO, 2006), making them brittle and causing symptoms similar to arthritis/arthritic pain over time.

The exact reference is:

The World Health Organisation (WHO) report states that, for adults, about 60% of absorbed fluoride is retained.  Most of ingested fluoride is absorbed, and most of retained fluoride is stored in the bones.  This means that approximately half of ingested fluoride is stored in the bones.  The exact quote, from pages 29 and 30 of the report, is:

Approximately 75-90 per cent of ingested fluoride is absorbed.  In an acidic stomach, fluoride is converted into hydrogen fluoride (HF) and up to about 40 per cent of the ingested fluoride is absorbed from the stomach as HF.

Once absorbed into the blood, fluoride readily distributes throughout the body, with approximately 99 per cent of the body burden of fluoride retained in calcium rich areas such as bone and teeth (dentine and enamel) where it is incorporated into the crystal lattice. In infants about 80 to 90 per cent of the absorbed fluoride is retained but in adults this level falls to about 60 per cent.

It should also be noted that fluoride is converted into hydrogen fluoride in the stomach.  Hydrogen fluoride is a notoriously dangerous acid, and in concentrated form relatively small spills have caused death.  For example, see:

Skeletal fluorosis due to fluoride in drinking water has been extensively reported in many countries, discussed in pages 97 to 117 of the WHO report.  For example, on page 101 data from China is presented where the rate of skeletal fluorosis was 12.4% in a region where the fluoride concentration was about 1 mg/L.

The early symptoms of skeletal fluorosis include painful and stiff joints (for example, see page 105).  The symptoms of skeletal fluorosis are discussed more extensively in the National Research Council report, on pages 5 and 6.  The exact quote is:

Fluoride increases bone density and appears to exacerbate the growth of osteophytes present in the bone and joints, resulting in joint stiffness and pain. The condition is categorized into one of four stages: a preclinical stage and three clinical stages that increase in severity. The most severe stage (clinical stage III) historically has been referred to as the "crippling" stage. At stage II, mobility is not significantly affected, but it is characterized by chronic joint pain, arthritic symptoms, slight calcification of ligaments, and osteosclerosis of the cancellous bones.

Fluoridation Overfeeds: Such accidents have caused mass poisonings, and occasionally killed people (Waldbott, 1982; Balbus, 2001).

The exact references are:

Waldbott (1982) reported seven cases of fluoridation overfeeds where people were poisoned.  In one case a dialysis patient died.  Balbus & Lang (2001) reported on three cases of fluoridation overfeeds where people were poisoned.  In one case, Hooper Bay, Alaska in 1992, hundreds were poisoned.  A previously healthy man of 41 died, and his sister was airlifted to hospital.  This case is discussed in more detail in the following reference:

This reference also reported another case where three dialysis patients died due to fluoridated water.  It should not need emphasising that something which kills people is not safe.

Citizens need not prove our water is dangerous, promoters of fluoridation must prove our water is safe.  The precautionary principle.

Promoters of fluoridation argue that the side-effects of water fluoridation are not absolutely proven, but refuse to provide evidence of safety.  This is not a valid argument.  As for any other medicine, claims of safety should be supported by evidence.  According to the precautionary principle, we should act to prevent harm that can reasonably be anticipated.  For discussion of the precautionary principle as it applies to fluoridation, see

When there is considerable evidence of harm due to water fluoridation, and no apparent benefit to swallowing fluoride, the only reasonable course of action is to end fluoridation.

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