Follow-up petition on health and environmental concerns regarding fluoridation of drinking water

Petition

Petition under the Auditor General Act, section 22 requesting the discontinuation of artificial water fluoridation

Fluoride has been treated differently for risk assessment than other trace elements found in water that have similar chronic toxic effects suggesting that it is a “protected pollutant”.

H2SiF6 and NaSiF6 are “Hazardous Waste”, “Toxic Substances” and “Dangerous Goods” which are causing harm to humans, aquatic life and the environment,

In violation of the Fishing Act,

section 34(1), which describe the provisions to conserve and protect fish habitat that sustain Canada’s fisheries resources,

section 35(1), which prohibits the harmful alteration, disruption or destruction (HADD) of fish habitat, and

sections 36-42 which control the deposition of any deleterious substance to water frequented by fish

[Original signed by Carole Clinch]

Carole Clinch
307 Normandy Avenue
Waterloo, Ontario
caclinch@gmail.com

April 14, 2008

Office of the Auditor General of Canada
Commissioner of the Environment and Sustainable Development
240 Sparks Street
Ottawa, Ontario K1A 0G6
Email: petitions@oag-bvg.gc.ca

---

Introduction: Artificial Water Fluoridation is not Sustainable

Background levels of fluoride for Lake Ontario and the St. Lawrence River are up to 0.25mg/L which is double the 0.12mg/L Canadian Water Quality Guideline (CWQG). DWSP http://www.ene.gov.on.ca/envision/water/dwsp/002/eastern/eastern.htm

A review by Camargo 2003 states: “Discharges of fluoridated municipal waters also cause significant increases (about five times the natural background level) in the fluoride concentration of recipient rivers (Sparks et al., 1983; Camargo et al., 1992a).”

Evidence from the study by Daemker and Dey 1989 indicates that Pacific salmon are harmed at levels of about 0.25mg/L.³ Evidence from Camargo²⁰ demonstrates that net-spinning caddisfly larvae are harmed at fluoride levels as low as 0.2mg/L.

Two food sources for salmon are also shown to be affected by fluoride at low levels. Fluoride levels below 0.1 ppm were shown to be lethal to the water flea, Daphnia magna.⁴ Alga (Porphyria tenera) was killed by a four-hour fumigation with fluoride with a critical concentration of 0.9 ppm.⁵

Such demonstrated harm of aquatic species is in violation of the Fishing Act. These violations are not sustainable.

Risk Analysis between Fluoride ion and other non-essential elements

STUDY #1: Risk Analysis between Fluoride ion and other non-essential elements

By: Limeback H, Thiessen K, Isaacson R, Hirzy W. 2007 The EPA MCLG for fluoride in drinking water: new recommendations. Abstract 1531. Poster number 406. SOT Poster.

OBJECTIVES

The purpose of this study was to conduct a risk analysis comparison between F- and other non-essential elements (e.g. Antimony Sb, Arsenic As, Beryllium Be, Cadmium Cd, Mercury Hg and Thallium Tl). Using recently published literature on fluoride toxicology, we set out to calculate new reference doses (RfD) for fluoride based on several endpoint outcomes and used these to recommend a range protective of health for all individuals, to help guide Health Canada in adjusting the MAC for fluoride in drinking water.

There are significant gaps in our understanding of the actual substance used in drinking water. This study also provides a brief presentation of the direct and indirect contribution of fluorosilicates to 2 other drinking water contaminants, arsenic and lead, and their quantified health effects.

METHODS

We used two different approaches to conduct this risk assessment and calculate new RfDs and MCLGs. First, a reference dose (RfD) was estimated from the no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-health-effect levels (LOAELs). Uncertainty factors were then assigned, using the other trace elements as models, and applied to NOAELs to estimate new MCLGs Second, the benchmark dose approach was also used, where enough information was available, but preliminary calculations determined that this approach did not alter the comparison. Very similar results were obtained. Due to space limitations, the data is not shown here.

RESULTS

Table 1. (adapted from data provided on the EPA website)

Contaminant (critical studies)	MCLG (mg/L)	MCL (mg/L)	Experimental Doses	UF (Uncertainty Factor)	MF (Modifying Factor)	RfD (Reference Dose)	Potential Health Effects	Sources of Contaminant in Drinking Water
Antimony Schroeder (1970)	0.006	0.006	NOEL: none LOAEL: 0.35 mg/kg bw/day	1000 (10 for interspecies conversion, 10 to protect sensitive individuals, and 10 because the effect level was a LOAEL and no NOEL was established)	1	0.0004 mg/kg/day	Increase in blood cholesterol; decrease in blood sugar	Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder
Arsenic Human Chronic oral exposure Tseng 1977; Tseng et al., 1968	0	0.010 as of 01/23/06	NOAEL: 0.009 mg/L converted to 0.0008 mg/kg-day LOAEL: 0.17 mg/L converted to 0.014 mg/kg-day	3 The UF of 3 is to account for both the lack of data to preclude reproductive toxicity as a critical effect and to account for some uncertainty in whether the NOAEL of the critical study accounts for all sensitive individuals.	1	0.0003 mg/kg-day	Skin damage or problems with circulatory systems, and may have increased risk of getting cancer	Erosion of natural deposits; runoff from orchards, runoff from glass & electronics production wastes
Beryllium Dog Dietary Study Morgareidge et al., 1976	0.004	0.004	BMD10: 0.46 mg/kg-day	300 10 for extrapolation for interspecies differences, 10 for consideration of intraspecies variation, and 3 for database deficiencies.	1	0.002 mg/kg-day	Intestinal lesions	Discharge from metal refineries and coal-burning factories; discharge from electrical, aerospace, and defense industries
Cadmium Human studies U.S. EPA, 1985	0.005	0.005	NOAEL (water): 0.005 mg/kg/day	10	1	0.0005 mg/kg/day (water)	Significant proteinuria	Corrosion of galvanized pipes; erosion of natural deposits; discharge from metal refineries; runoff from waste batteries and paints
Fluoride Hodge, 1950, cited in Underwood, 1977		1.5	NOAEL: 1 ppm (converted 0.06 mg/kg/day LOAEL: 2 ppm	1	1	0.06 mg/kg/day	Bone disease (pain and tenderness of the bones); Children may get mottled teeth	Water additive which promotes strong teeth (sic); erosion of natural deposits; discharge from fertilizer and aluminum factories
Mercury (inorganic)	0.002	0.002	Water intake data not available Air pollution data on file	NA	NA	0.0003 mg/kg/day	Kidney damage	Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands
Thallium Rat Oral Subchronic Study U.S. EPA, 1986	0.0005	0.002	NOAEL: 0.25 mg/kg/day (Tl2SO4) (converted to 0.23 mg/kg/day Tl2CO3) LOAEL: None	3000 10 to extrapolate from sub-chronic to chronic data, 10 for interspecies variability and a factor of 3 to account for lack of reproductive and chronic toxicity data	1	0.00008 mg/kg/day	Hair loss; changes in blood; kidney, intestine, or liver problems	Leaching from ore-processing sites; discharge from electronics, glass, and drug factories

Table 2: Proposed RfD and MCLG based on health endpoints with UF

Endpoint for selecting a new fluoride MCLG (source: NRC Report)	Recommended Uncertainty Factor (UF)	NOAEL	Proposed RfD = NOAEL/UF	Proposed MCLG
Endocrine effects -pineal function -thyroid function -diabetes	10 (to protect sensitive populations, e.g. low iodine intake, malnutrition)	0.03 mg/kg-day Based on LOAEL- the NOAEL is likely lower	0.003 mg/kg-day	0.05 ppm (calculation based on a reference wt. of a 36 kg 10-yr.-old consuming 2 L water/day)
Neurological effects -human studies (IQ)	10 (to protect sensitive populations, e.g. renal patients)	0.05 mg/kg-day	0.005 mg/kg-day	0.09 ppm (calculation based on a reference wt. of a 36 kg 10-yr.-old consuming 2 L water/day)
Severe dental fluorosis NRC	3 (to protect sensitive patients e.g. diabetes insipidus, exposure to general anesthetic, calcium and protein deficiency)	0.05 mg/kg-day (NRC, EPA)	0.0167 mg/kg-day	0.33 ppm (calculation based on a reference weight of 10 kg 1 yr. and 1 water /day)
Moderate-Severe dental fluorosis	3 (to protect sensitive patients e.g. diabetes insipidus, exposure to general anesthetic, calcium and protein deficiency)	0.02 mg/kg-day (based on a  NOAEL of 0.1 ppm)	0.0067 mg/kg-day	0.13 ppm (calculation based on a reference weight of 10 kg 1 yr. and 1 water /day)
Bone fracture WHO*	10 (to protect sensitive populations, e.g. renal dialysis patients, elderly)	6 mg/day (adult*) = 0.086 mg/kg-day (adult)	0.0086 mg/kg-day	0.2 ppm (calculation based on 5% of adults drinking 3 L water/day)
Joint pain (Stage II Skeletal Fluorosis)	3 (to protect sensitive populations, e.g. renal dialysis patients)	3 mg/day (adult) =0.043 mg/kg-day	0.014 mg/kg-day	0.3 ppm (calculation based on 5% of adults drinking 3 L water/day)

Note: Neither the US EPA nor Health Canada has created an MCLG or equivalent for fluoride which would be protective of health for susceptible populations for a lifetime of ingestion.

The following chart shows that the current MAC of 1.5 ppm for F- is 100 to 1,000 times higher than the other trace metals, despite evidence to show that appropriate reference doses for fluoride (Table 2) are not that much different.

Table 3: Comparison of MAC/MCL and RfD

Water Contaminant	MCLG	MAC Canada MCL USA	RfD
Antimony (Sb)	0.006mg/L	0.006mg/L	0.0004mg/kg/day
Arsenic (As)	0 USA only	0.010mg/L	0.0003mg/kg/day
Beryllium (Be)	0.004mg/L	0.004mg/L	0.002mg/kg/day
Cadmium (Cd)	0.005mg/L	0.005mg/L	0.0005mg/kg/day
Fluoride (F-)		1.5mg/L Canada 4mg/L USA	0.06mg/kg/day
Mercury (Hg)	0.002mg/L	0.002mg/L	0.0003mg/kg/day/kg/day
Thallium (Tl)	0.0005mg/L	0.002mg/L	0.00008mg/kg/day

This chart shows that the RfD of 0.06mg/kg/day is 10-100 times higher than the other trace metals, despite evidence to show that appropriate reference doses for fluoride (Table 2) are not that much different. This study demonstrates that the RfD for fluoride is too high and provides an estimate of how much it should be adjusted downward. Currently the RfD for fluoride is one to two orders of magnitude higher than comparable trace metals and should be adjusted to 0.006 or 0.0006 to be protective of susceptible populations.

The Health Canada Tolerable Daily Intake (TDI) of fluoride is 105 µg/kg body weight/day or 0.105mg/kg/day. For a 70 kg Canadian adult, this would correspond to a TDI of 7.35 mg/day.

NRC 2006 Report2 (chapter 2, p31) indicates that many susceptible members of our population exceed this TDI. For example, a diabetic patient consuming 10-12 liters of water/day (p31) consuming water fluoridated at 1mg/L as recommended by Health Canada, would consume 10-12 mg fluoride from drinking water alone. Fluoride from dental products, air pollution, consumer products, foods high in fluoride such as tea would add more to the fluoride burden, with a total of more than 10mg/day, exceeding even the Tolerable Upper Intake Levels (UL) of 10mg/day.

Those with kidney disease and young children eliminate as little as 15% of fluoride per day,⁵³ leaving a fluoride accumulation in their bodies well in excess of the 50% assumed with a healthy adult.

The Physician’s Desk Reference also discusses the 1-4% of the population which may be hypersensitive to fluorides. Our understanding of allergic and hypersensitive reactions is enhanced by the research on penicillin and peanuts. For some individuals there is no safe dose.

 “It becomes obvious upon slight reflection that, in assessing the effects that extremely low levels of pollutants have on human populations, a far greater chance of success is assured by studying the most susceptible populations. Such a procedure avoids the “diluting” effect of a random sample.”⁵⁴

STUDY #2: Adverse Health Effects from Fluoride in Drinking Water
By: Kathleen M. Thiessen, Ph.D., SENES Oak Ridge, Inc., Center for Risk Analysis,
102 Donner Drive, Oak Ridge, Tennessee 37830, (865) 483-6111, kmt@senes.com

The following charts show that the EPA RfD of 0.06mg/kg/day is not protective for most end-points of health; especially in infants. 

Graph 1

This first graph shows estimated fluoride intakes for each age group (mg of fluoride per kg of body weight per day), assuming the range of tap water intakes shown in Slide 2 and a fluoride concentration in the tap water of 0.8 ppm (0.8 mg fluoride per liter of water). Also shown is EPA’s reference dose, which is defined as “an estimate of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.” For fluoride, the reference dose is 0.06 mg per kg per day.

As seen in the graph, many infants have a fluoride intake just from tap water that exceeds EPA’s reference dose for fluoride. Children (ages 1-10) with high water consumption also exceed EPA’s reference dose. Older children (youth) and adults with high water consumption are very close to EPA’s reference dose.

Note that this graph shows estimated fluoride intakes only from tap water. These estimates do not include fluoride intakes from other sources, such as commercial beverages (which are often made with fluoridated tap water), toothpaste, tea, or food. When these other sources of fluoride intake are included, total fluoride intakes for many members of all age groups exceed EPA’s reference dose.

 

Graph 2

Graph 2 shows the estimated fluoride intakes from tap water from Slide 3, plus estimates of the “no-effect” levels for various adverse health effects. These “no-effect” levels represent fluoride intakes at or below which most people are not expected to experience any harmful effects. Note that these estimates are based on average exposures of study populations; these estimates do not include any margin of safety, and they might not be protective for all individuals. Intakes above these levels cannot be considered safe.

Note also that most of these “no-effect” levels are lower than EPA’s reference dose for fluoride. In other words, EPA’s reference dose is not protective for most of these health endpoints.

Note also that most of these “no-effect” levels are exceeded by many members of the population, of all ages, just from fluoride at 0.8 ppm in community drinking water. When other fluoride sources are included, even more people are expected to exceed the “no-effect” levels. In order to be “safe” for all members of the population, fluoride intakes for all people must be kept below the lowest “no-effect” levels, when all sources of fluoride intake are included, and with an adequate margin of safety.

This list of adverse health effects does not include cancer. For carcinogenic substances, the risk of cancer increases with the amount of exposure, such that even a very low exposure carries with it some cancer risk. A carcinogenic (cancer-causing) effect of fluoride cannot be ruled out from the available data, and at the very least, a cancer-promoting effect is likely.

CONCLUSIONS

The comparison in study number 1 and 2 shows clearly that fluoride has been treated differently for risk assessment than other trace elements found in water that have similar chronic toxic effects. In addition, new evidence is accumulating that humans are negatively affected by lower levels than have previously been considered harmful.

Study #1 estimates for a new fluoride maximum allowable contaminant level (MAC) focused (Table 2) on available evidence for fluoride effects on endocrine systems, the neurological system, and the musculoskeletal system, particularly teeth and bones. The US EPA derivation of the MCLs for other trace elements is based on RfDs (reference doses) calculated from experimental No Observed Adverse Effects Level (NOAELs) and Lowest Observed Adverse Effects Levels (LOAELs) and uncertainty factors that ranged from 3 to 3000.

In order to protect the entire population from the harmful effects of fluoride at low daily intake in drinking water study #1 used uncertainty factors that would result in reasonable RfDs. The uncertainty factors considered ranged from 1, where sufficient data from humans studies were available, to 10, where good studies on susceptible populations were lacking. These RfDs for fluoride are still an order of magnitude higher than those listed in table 1 for other trace elements, indicating that these reference doses for fluoride may still be too high.

By combining reasonable reference doses and uncertainty factors that can be justified on the basis of protecting susceptible populations, their calculations resulted in recommended levels for fluoride in drinking water that ranged from 0.33 mg/L to as low as 0.06 mg/L. Since maximum allowable contaminant (MAC/MCL) levels are selected based on practicalities and costs associated with lowering the contaminants, MAC/MCLs < 0.10 mg/L may be impractical as so many natural water supplies in Canada and the United States contain fluoride that exceed 0.1 mg/L. However, an MAC of 0.4mg/L is practical.

This study demonstrates that the US EPA RfD for fluoride of 0.06mg/kg/day is not protective of good health and must be adjusted downward. This study demonstrates that the Health Canada TDI of 105 µg/kg (0.105 mg/kg/day) body weight/day is not protective of good health and must be adjusted downward.

RECOMMENDATIONS based on above risk analysis:

1. The recommended MCLG for fluoride is 0.
2. The recommended MAC for fluoride is 0.4mg/L.
3. The addition of artificial water fluoridation chemicals (hydrofluorosilicic acid and derivatives) to drinking water should be discontinued.

QUESTIONS

1. The EPA Reference Dose of 0.06mg/kg/day for fluoride is 10-100 times higher than the other trace metals, despite evidence to show that appropriate reference doses for fluoride (Table 2) are not that much different. The Health Canada TDI is 105 µg/kg body weight/day for fluoride (0.105mg/kg/day for fluoride) which is 100 to 1,000 times higher than other trace metals. Neither EPA’s reference dose nor Health Canada’s TDI are protective for most of the health endpoints discussed in the above analysis by 3 authors of the National Research Council Report on Fluorides in Drinking Water and a senior EPA chemist, who are internationally recognized as experts in the field of fluoride toxicology . Does Health Canada disagree with their assessment which demonstrates that fluoride, ingested for a lifetime at current recommended levels, is NOT protective of health for all individuals?
2. According to Table 2-4 in the NRC 2007 Report on Fluorides, someone with Nephrogenic Diabetes Insipidus would exceed the EPA RfD and TDI from drinking water sources alone (this does not include fluoride from other sources such as food, beverages, dental products, drugs, air, consumer products, etc.). (10.5liters x 0.8mg/L= 8.4mg/day of fluoride) (10.5liters x 1.0mg/L = 10.5mg/day of fluoride) Does Health Canada have evidence that 10.35mg/day fluoride ingested just from water, for a lifetime for these individuals is protective of their health? If yes, please provide evidence.
3. According to Table 2-4 in the NRC 2006 Report on Fluorides athletes and workers also exceed the EPA RfD and TDI from drinking water sources alone (8.4liters x 0.8mg/L = 6.72mg/day of fluoride) (8.4liters x 1.0mg/L = 8.4mg/day of fluoride) These individuals also eat larger quantities of food and fluoride derived from food. Does Health Canada believe that 8.4mg/day fluoride ingested just from water, for a lifetime, is protective of the health for these individual who consume large quantities of water? If yes, please provide evidence.
4. The above risk analysis demonstrates that endocrine organs may be the most susceptible part of the body to fluoride toxicity. Does Health Canada have evidence which clearly demonstrates that this analysis completed by some of the world’s leading authorities on fluoride toxicity is incorrect? If so, how so?
5. The above analysis demonstrates that the brain is particularly susceptible to fluoride toxicity. With 70 laboratory studies and 20 newly-translated studies around the world demonstrating a lowering of IQ with fluoride concentrations in drinking water very close to the current recommended doses (see discussion in NRC 2006) and other new studies demonstrating neurotoxic effects of fluoride (e.g. Alzheimer’s, Down Syndrome), does Health Canada have evidence to demonstrate that there is an adequate margin of safety between toxic dose and safe dose and that fluoride is not implicated in these neurotoxic effects? Please provide evidence.
6. With the increased incidence of osteoporosis and arthritis, can Health Canada provide irrefutable evidence that water fluoridation has had no impact on these increases?
7. With the increased incidence of diabetes and kidney disease, can Health Canada provide irrefutable evidence that water fluoridation has had no impact on these increases?
8. According to the NRC 2006 Report, “Aluminum combined with fluoride in very small quantities (0.5mg/L) influences the following; Thyroid Hormone; Growth Hormone; Melatonin; Neural Transmitters; Insulin/Glucagon; Prostaglandins; Vasopressin etc.” Knowing that the quantity of water therefore the dose of fluoride and hydrofluorosilicates from drinking water ingested by individuals cannot be controlled because you cannot tell people how much to eat or drink, can Health Canada prove that this NRC assessment by 11 international researchers in fluoride toxicity is incorrect and that there is no risk from ingesting hydrofluorosilicic acid and released fluoride ions? If so, how so?
9. Aluminum-Fluoride (AlFx) is a small inorganic molecule that mimics the chemical structure of a phosphate which the body uses as energy currency and in signal transduction. Can Health Canada provide evidence that AlFx will not interfere with homeostasis, health or well-being when fluorosilicates and aluminum are ubiquitous in our environment? Please provide references.
10. “In Canada, actual intakes are larger than recommended intakes for formula-fed infants and those living in fluoridated communities. Efforts are required to reduce intakes among the most vulnerable age group, children aged 7 months to 4 years. ” (Ont. Min Health 1999 Review ) According to Table 2-4 in the NRC 2006 Report on Fluorides lactating mothers drink up to 10 liters of water a day. Can Health Canada provide evidence that lactating mothers (high water consumers) and their newborn children will not be harmed by the high dose of fluoride they would consume if they lived in a fluoridated city?
11. Just 4 glasses (1 liter) of fluoridated water are sufficient to suppress thyroid function, according to the NRC 2006 report if you are iodine insufficient and weigh 70kg. Doctors recommend that we drink 2 liters a day. The risk analysis by Dr. Thiessen, co-author of the NRC 2006 Report on Fluorides in Drinking Water also demonstrates that the thyroid gland may be the most sensitive organ in the body to fluoride toxicity. Does Health Canada have evidence to disprove the Thiessen risk assessment and the NRC 2006 Report? Please provide references.
12. Health Canada currently recommends that municipalities buy fluoridation additives (hydrofluorosilicic acid) from companies to put into our drinking water. Should companies not pay municipalities for safe disposal of these CEPA-designated “toxic substances”, “hazardous substances” and Transport Canada-designated “dangerous goods”?
13. The York Review 2000 discusses the very poor quality of the old epidemiology studies and the 2 members of the York Review have signed a petition asking for the discontinuation of water fluoridation. 2 members of the York Review advisory state: “Water fluoridation has not been proved to reduce tooth decay... No drug would be licensed for effectiveness or safety on the present evidence.” The 1999 Ont Min Health Review states: "The magnitude of [fluoridation's] effect is not large in absolute terms, is often not statistically significant and may not be of clinical significance." The 2007 Pizzo Review states: “it is now accepted that systemic fluoride plays a limited role in caries prevention.” Does Health Canada disagree with the conclusions of these 3 recent reviews that water fluoridation is ineffective?
14. Would Health Canada please provide a single recent study which demonstrates that H2SiF6 or fluoride has any significant effect on the reduction of cavities?
15. Health Canada and the Food and Nutrition Board of the Institute of Medicine in 1997 determined that 10 liters of water was the Upper Tolerance Limit (UL). The [position withheld] for Health Canada stated in Dryden, Ontario that “you would have to drink 20,000 liters of fluoridated water to get a toxic dose”. Does Health Canada agree with the [position withheld] on this issue? If so, what is the difference between a toxic dose and a lethal dose?
16. Hooper Bay, Alaska, May 1992 reported a fluoride overfeed accident resulting in ONE DEATH, 260 poisoned, one airlifted to hospital in critical condition. How many fatalities and other health-related problems have resulted from overfeed accidents from fluoridation systems?
17. The [position withheld] for Health Canada recently stated: “In for example, British Columbia you tend to have a lot of what we call tree-huggers or environmentalist folks. They tend to feel that they are not comfortable with fluoride in the water.” (December 3 2007 to Thunder Bay City Council). Does Health Canada agree with this assessment that those concerned with the environmental impact of adding CEPA toxic substances to our drinking water, hence source water, are “tree-huggers”?
18. As a civil servant working at the taxpayers' expense does the [position withheld] for Health Canada have any obligation to present an accurate and balanced portrayal of all the actual research and the valid environmental, legal, ethical and public concerns regarding the complex subject of water fluoridation chemicals or is the Health Canada mandate for the [position withheld] to present only the research which supports water fluoridation?
19. The “no effect” levels in the Thiessen analysis below which no health harm occurs are lower than EPA’s reference dose for fluoride. The EPA’s reference dose for fluoride is lower than the TDI Health Canada uses. Can Health Canada provide irrefutable evidence that the TDI and the EPA reference dose are protective of all individuals and that the above analysis is incorrect?

Citations

1. Strunecka A, Patocka J, Blaylock RL, Chinoy N. 2007 Fluoride Interactions: From Molecules to Disease. Current Signal Transduction Therapy 2: 190-213.
2. Li L. (2003). The biochemistry and physiology of metallic fluoride: action, mechanism, and implications. Critical Reviews of Oral Biology and Medicine 14(2):100-14.
3. Wittinghofer A. 1997 Signaling mechanistics: aluminum fluoride for molecule of the year. Current Biology 7:R682-5.

Government Agencies: Health Canada, Fisheries and Oceans, Public Health Service, Environment Canada

[top of page]

Minister's Response: Environment Canada

18 August 2008

Ms. Carole Clinch
307 Normandy Avenue
Waterloo, Ontario
N2K 1X6

Dear Ms. Clinch:

I am pleased to respond to your Environmental Petition No. 221-D, which you sent to the Interim Commissioner of the Environment and Sustainable Development, regarding drinking water fluoridation. Your petition was received in Environment Canada on April 29, 2008.

Due to the nature of the issues raised in your petition, Environment Canada has collaborated with Health Canada to prepare a joint response. My colleague, the Honourable Tony Clement, Minister of Health, will respond to your petition on behalf of the Government.

Thank you for your interest in this important issue.

Sincerely,

[Original signed by John Baird, Minister of the Environment]

John Baird, P.C., M.P.

c.c.: The Honourable Tony Clement, P.C., M.P.
Mr. Ronald C. Thompson, Interim Commissioner of the Environment and Sustainable Development

---

[top of page]

Joint Response: Health Canada, Public Health Agency of Canada

26 August 2008

Ms. Carole Clinch
307 Normandy Avenue
Waterloo, Ontario N2K 1X6

Dear Ms. Clinch:

This is in response to your environmental petition no. 221-D of April 14, 2008, addressed to Mr. Ronald C. Thompson, the former Interim Commissioner of the Environment and Sustainable Development (CESD).

In your petition you raised concerns about the addition of fluoridation chemicals to drinking water as it relates to its safety, toxicity and efficacy.

I am pleased to provide you with the enclosed joint Health Canada and Public Health Agency of Canada response to your petition.

I appreciate your interest in this important matter, and I hope that you will find this information useful.

[Original signed by Tony Clement, Minister of Health and the Minister for the Federal Economic Development Initiative for Northern Ontario]

Yours sincerely,

Tony Clement

Enclosure

c.c. Mr. Scott Vaughan, CESD
The Honourable John Baird, P.C., M.P.

---

Response to
Environmental Petition 221D filed by Ms. Carole Clinch
under Section 22 of the Auditor General Act
Received April 29, 2008

Petition requesting the discontinuation of artificial water fluoridation

August 27, 2008

Minister of Health and the Minister for the Federal Economic
Development Initiative for Northern Ontario,
Minister of the Environment

Background:

Health Canada works with the provinces and territories to develop the Guidelines for Canadian Drinking Water Quality. The Guidelines are then used by each province and territory as a basis to establish their own requirements for drinking water quality. Fluoride is one of the many substances for which a guideline has been established. The Maximum Acceptable Concentration (MAC) for fluoride has been established taking into consideration all sources of exposure to fluoride, including foods and dental products. In Canada, the fluoridation of drinking water supplies is a decision that is made by each municipality, in collaboration with the appropriate provincial or territorial authority. This decision may also include consultation with residents, often through a referendum.

Fluoride occurs naturally in many source waters in Canada. It can also be added to drinking water as a public health measure to protect dental health and prevent or reduce tooth decay. The fluoridation of drinking water supplies is a well-accepted measure to protect public health and is strongly supported by scientific evidence. Fluoride is used internationally to protect dental health. It has been added to public drinking water supplies around the world for more than half a century, as a public health/dental health measure. The use of fluoride in the prevention of dental caries continues to be endorsed by over 90 national and international professional health organizations including Health Canada, the Canadian Dental Association, the Canadian Medical Association, the World Health Organization and the Food and Drug Administration of the United States.

As part of its ongoing review of the health effects of exposure to fluoride in drinking water, Health Canada convened a panel of experts in January 2007 to provide advice and recommendations based on the current state of relevant science with respect to the fluoridation of water. Advice was sought from the Expert Panel on five specific issues of concern including Total Daily Intake of Fluoride; Dental Fluorosis; Other Health Effects; Risk Assessment; and Drinking Water Fluoridation: Risks and Benefits. Discussions were based on topic-specific literature reviews developed and presented by some of the invited experts.

The report produced by the Expert Panel will be used to help inform the development of an updated fluoride guideline for Canadian drinking water, by ensuring our analysis is based on the latest sciencific evidence. The Expert Panel report was posted online and can be found at http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/2008-fluoride-fluorure/index-eng.php.

Health Canada will continue to monitor the science and review new scientific reports and articles which explore possible links between fluoride and various health effects to ensure the health of Canadians is protected.

1.         The EPA Reference Dose of 0.06mg/kg/day for fluoride is 10-100 times higher than the other trace metals, despite evidence to show that appropriate reference doses for fluoride (Table 2) are not that much different. The Health Canada TDI is 105 µg/kg body weight/day for fluoride (0.105mg/kg/day for fluoride) which is 100 to 1,000 times higher than other trace metals. Neither EPA’s reference dose nor Health Canada’s TDI are protective for most of the health endpoints discussed in the above 9 analysis by 3 authors of the National Research Council Report on Fluorides in Drinking Water and a senior EPA chemist, who are internationally recognized as experts in the field of fluoride toxicology. Does Health Canada disagree with their assessment which demonstrates that fluoride, ingested for a lifetime at current recommended levels, is NOT protective of health for all individuals?

4.         The above risk analysis demonstrates that endocrine organs may be the most susceptible part of the body to fluoride toxicity. Does Health Canada have evidence which clearly demonstrates that this analysis completed by some of the world’s leading authorities on fluoride toxicity is incorrect? If so, how so?

Answer to Questions 1 & 4:

It is not appropriate for Health Canada to comment on an individual’s opinion. Health Canada’s conclusions are based on internal scientific reviews of original relevant scientific studies that are published in internationally recognized peer-reviewed journals.

2.         According to Table 2-4 in the NRC 2007 Report on Fluorides, someone with Nephrogenic Diabetes Insipidus would exceed the EPA RfD and TDI from drinking water sources alone (this does not include fluoride from other sources such as food, beverages, dental products, drugs, air, consumer products, etc.). (10.5liters x 0.8mg/L= 8.4mg/day of fluoride) (10.5liters x 1.0mg/L = 10.5mg/day of fluoride) Does Health Canada have evidence that 10.35mg/day fluoride ingested just from water, for a lifetime for these individuals is protective of their health? If yes, please provide evidence.

3.         According to Table 2-4 in the NRC 2006 Report on Fluorides athletes and workers also exceed the EPA RfD and TDI from drinking water sources alone (8.4liters x 0.8mg/L = 6.72mg/day of fluoride) (8.4liters x 1.0mg/L = 8.4mg/day of fluoride) These individuals also eat larger quantities of food and fluoride derived from food. Does Health Canada believe that 8.4mg/day fluoride ingested just from water, for a lifetime, is protective of the health for these individual who consume large quantities of water? If yes, please provide evidence.

10.        “In Canada, actual intakes are larger than recommended intakes for formula-fed infants and those living in fluoridated communities. Efforts are required to reduce intakes among the most vulnerable age group, children aged 7 months to 4 years. ” (Ont. Min Health 1999 Review). According to Table 2-4 in the NRC 2006 Report on Fluorides lactating mothers drink up to 10 liters of water a day. Can Health Canada provide evidence that lactating mothers (high water consumers) and their newborn children will not be harmed by the high dose of fluoride they would consume if they lived in a fluoridated city?

Answer to Questions 2, 3 & 10:

Health Canada uses a population-based approach in risk assessment and therefore establishes drinking water guidelines based on the sub-population likely to be most affected. The sub-population most affected by exposure to fluoride is young children aged 22-26 months old, which is also the sub-population used for establishing a drinking water guideline which is protective of all Canadians. There are no data to suggest that exposure to fluoride at typical levels found in drinking water (e.g., at or below the Canadian maximum acceptable concentration of 1.5 mg/L) would result in adverse effects for those consuming larger quantities of drinking water.

5.         The above analysis demonstrates that the brain is particularly susceptible to fluoride toxicity. With 70 laboratory studies and 20 newly-translated studies around the world demonstrating a lowering of IQ with fluoride concentrations in drinking water very close to the current recommended doses (see discussion in NRC 2006) and other new studies demonstrating neurotoxic effects of fluoride (e.g. Alzheimer’s, Down Syndrome), does Health Canada have evidence to demonstrate that there is an adequate margin of safety between toxic dose and safe dose and that fluoride is not implicated in these neurotoxic effects? Please provide evidence.

6.         With the increased incidence of osteoporosis and arthritis, can Health Canada provide irrefutable evidence that water fluoridation has had no impact on these increases?

7.         With the increased incidence of diabetes and kidney disease, can Health Canada provide irrefutable evidence that water fluoridation has had no impact on these increases?

11.        Just 4 glasses (1 liter) of fluoridated water are sufficient to suppress thyroid function, according to the NRC 2006 report if you are iodine insufficient and weigh 70kg. Doctors recommend that we drink 2 liters a day. The risk analysis by Dr. Thiessen, co-author of the NRC 2006 Report on Fluorides in Drinking Water also demonstrates that the thyroid gland may be the most sensitive organ in the body to fluoride toxicity. Does Health Canada have evidence to disprove the Thiessen risk assessment and the NRC 2006 Report? Please provide references.

Answer to Questions 5, 6, 7 & 11:

Based on currently available published scientific literature, the weight of evidence does not support the claim that fluoride contributes to these adverse health effects.

8.         According to the NRC 2006 Report, “Aluminum combined with fluoride in very small quantities (0.5mg/L) influences the following; Thyroid Hormone; Growth Hormone; Melatonin; Neural Transmitters; Insulin/Glucagon; Prostaglandins; Vasopressin etc.” Knowing that the quantity of water therefore the dose of fluoride and hydrofluorosilicates from drinking water ingested by individuals cannot be controlled because you cannot tell people how much to eat or drink, can Health Canada prove that this NRC assessment by 11 international researchers in fluoride toxicity is incorrect and that there is no risk from ingesting hydrofluorosilicic acid and released fluoride ions? If so, how so?

9.         Aluminum-Fluoride (AlFx) is a small inorganic molecule that mimics the chemical structure of a phosphate which the body uses as energy currency and in signal transduction. Can Health Canada provide evidence that AlFx will not interfere with homeostasis, health or well-being when fluorosilicates and aluminum are ubiquitous in our environment? Please provide references.

Answer to Questions 8 & Q9:

There is no data to suggest that humans are exposed to hydrofluorosilicic acid through drinking water or that aluminum combines with fluoride in drinking water.

12.        Health Canada currently recommends that municipalities buy fluoridation additives (hydrofluorosilicic acid) from companies to put into our drinking water. Should companies not pay municipalities for safe disposal of these CEPA-designated “toxic substances”, “hazardous substances” and Transport Canada designated “dangerous goods”?

In Canada, the responsibility for managing hazardous waste rests primarily with the provinces and territories, who control the waste producers, the recycling, processing and elimination facilities, and the transportation of waste within their territory. The main definitions for hazardous wastes in Canada are under CEPA regulations for exports and imports of hazardous wastes and hazardous recyclable materials. Fluoridation additives certified for use in drinking water are not classified as hazardous waste in Canada.

13.        The York Review 2000 discusses the very poor quality of the old epidemiology studies and the 2 members of the York Review have signed a petition asking for the discontinuation of water fluoridation. 2 members of the York Review advisory state: “Water fluoridation has not been proved to reduce tooth decay... No drug would be licensed for effectiveness or safety on the present evidence.” The 1999 Ont Min Health Review states: "The magnitude of [fluoridation's] effect is not large in absolute terms, is often not statistically significant and may not be of clinical significance." The 2007 Pizzo Review states: “it is now accepted that systemic fluoride plays a limited role in caries prevention.” Does Health Canada disagree with the conclusions of these 3 recent reviews that water fluoridation is ineffective?

As stated earlier, it is not appropriate for Health Canada to comment on the opinion or position of individuals or agencies. Health Canada’s conclusions are based on internal scientific reviews of original relevant scientific studies that are published in internationally recognized peer-reviewed journals.

14.        Would Health Canada please provide a single recent study which demonstrates that H2SiF6 or fluoride has any significant effect on the reduction of cavities?

For specific information on scientific studies, please consult Health Canada’s Guideline Technical Document on Fluoride available on the Health Canada website at http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/environ/fluor-eng.php or the original peer-reviewed studies.

15.        Health Canada and the Food and Nutrition Board of the Institute of Medicine in 1997 determined that 10 liters of water was the Upper Tolerance Limit (UL). [Position withheld] for Health Canada stated in Dryden, Ontario that “you would have to drink 20,000 liters of fluoridated water to get a toxic dose”. Does Health Canada agree with the [position withheld] on this issue? If so, what is the difference between a toxic dose and a lethal dose?

The statement attributed to [name withheld] is taken out of context: he was commenting on acute exposures causing immediate death. The Upper Tolerance Limit item you refer to is a chronic exposure value. The acute and chronic exposures you present are not comparable.

16.        Hooper Bay, Alaska, May 1992 reported a fluoride overfeed accident resulting in ONE DEATH, 260 poisoned, one airlifted to hospital in critical condition. How many fatalities and other health-related problems have resulted from overfeed accidents from fluoridation systems?

Literature reports indicate that the incident in Hooper Bay was linked to extremely high fluoride concentrations, ranging up to 100 times the Canadian maximum acceptable concentration. Health Canada does not track such information, as fluoridation is a provincial/territorial responsibility.

17.        The [position withheld] for Health Canada recently stated: “In for example, British Columbia you tend to have a lot of what we call tree-huggers or environmentalist folks. They tend to feel that they are not comfortable with fluoride in the water.” (December 3 2007 to Thunder Bay City Council). Does Health Canada agree with this assessment that those concerned with the environmental impact of adding CEPA toxic substances to our drinking water, hence source water, are “tree-huggers”?

The statement attributed to [name withheld] is taken out of context: he was saying that some areas of the country seem to have heightened concerns as compared to other areas of the country. British Columbia currently has about 4% of its population drinking fluoridated water, whereas provinces like Ontario, Manitoba and Alberta have over 70%.

18.        As a civil servant working at the taxpayers' expense does the [position withheld] for Health Canada have any obligation to present an accurate and balanced portrayal of all the actual research and the valid environmental, legal, ethical and public concerns regarding the complex subject of water fluoridation chemicals or is the Health Canada mandate for the [position withheld] to present only the research which supports water fluoridation?

Among the roles of the [position withheld], one is to present Health Canada’s position on water fluoridation, which is based on internal scientific reviews of original relevant scientific studies that are published in internationally recognized peer-reviewed journals, as well as to promote effective, preventive public health measures such as water fluoridation.

An expert panel was formed to provide Health Canada with advice and recommendations on the current state of relevant science with respect to the fluoridation of water. The report from the panel reinforces Health Canada's position that water fluoridation is important from a public health perspective and that our position on water fluoridation is sound. The report's recommendations are based on the latest science. In undertaking the study, Health Canada consulted with a number of experts including scientists from the Universities of British Columbia, Toronto, Iowa; scientists from many areas of Health Canada; and also received input from the Canadian Dental Association, the U.S. Environmental Protection Agency and public health experts from Canada and the U.S.

Health Canada endorses the fluoridation of drinking water to prevent tooth decay, but does not make the decision on whether or not to fluoridate drinking water. Provincial and territorial governments are primarily responsible for the safety of drinking water. In collaboration with their municipalities, they decide whether or not to fluoridate and the amount of fluoride to be added.

19.        The “no effect” levels in the Thiessen analysis below which no health harm occurs are lower than EPA’s reference dose for fluoride. The EPA’s reference dose for fluoride is lower than the TDI Health Canada uses. Can Health Canada provide irrefutable evidence that the TDI and the EPA reference dose are protective of all individuals and that the above analysis is incorrect?

It is not appropriate for us to comment on the findings of a single study in this response. Health Canada’s conclusions are based on internal scientific reviews of available relevant information, using a weight of evidence approach. For further information, please consult the Guideline Technical Document on Fluoride available on the Health Canada website at http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/environ/fluor-eng.php.