Water Fluoridation in Canada


What is Fluoride?

Fluoride is a chemical ion composed of fluorine and another element. Fluorine is an element that is missing an electron, so it will naturally bond with an element that has an extra electron. Elements like Lithium, Beryllium and Aluminum all bond to fluorine to make different fluoride compounds. Fluorides are naturally found in food, soil, and both fresh and salt water.

This diagram shows the electron shell of a fluorine atom

This diagram shows the electron shell of a fluorine atom

Fluoride treatments have been proven to strengthen tooth enamel, the outer covering of teeth. Enamel can be weakened when bacteria in the mouth combine with sugars to form acids that cause tooth decay. Daily intakes of fluoride can also be used to prevent this decay as well as making the enamel harder. You can find the type of fluoride in your toothpaste on the label.

Fluoridation of Drinking Water

Fluoridation of water is supported by many national and international organizations. The World Health Organizations, Centers for Disease Control and Prevention, Health Canada, and multiple dental associations, including the American, Canadian and provincial associations believe water fluoridation helps with dental problems. Health Canada has even declared water fluoridation a public health issue.

Some areas around the world already have high levels of fluorides in their soil and water sources. These areas include volcanic rich soils, igneous and metamorphic rock formations, and mountain ranges with high levels of marine sediment. Almost all water contains some naturally occurring fluoride, but usually at levels too low to prevent tooth decay. Many communities choose to adjust the fluoride concentration in the water supply to a level beneficial to reduce tooth decay and promote good oral health.

In Canada, Brantford, Ontario was the first community to fluoridate their water supply in 1945. Water treatment is the responsibility of the municipal governments but is regulated by federal and provincial governments. Therefore, communities across Canada have the choice of whether to fluoridate their water. As of 2009, 45% of Canadian residents have fluoridated water. Canada is one of the most fluoridated countries in the world. In comparison, only 5.7% of the world’s population has their public water supply fluoridated. The provinces with the highest rates of water fluoridation are Ontario, Alberta and Manitoba while the provinces with the lowest rates are British Columbia and Newfoundland. There is no fluoridation of drinking water in Yukon and Nunavut. In the United States, 72% of the population has access to fluoridated water. In Canada, fluoride levels are highly monitored. In 2007, an expert panel concluded that 0.7 ppm was the optimal level of water fluoridation without causing adverse effects.

Benefits of Water Fluoridation

When fluoride was added to the water in Brantford, Ontario in 1945 it was as a test of the benefits of water fluoridation, with Sarnia, Ontario being the comparative city without fluoridation. Researchers found a significant drop in the severity of cavities where water was fluoridated in Brantford compared to where it was not in Sarnia. It has been found that the health benefits of fluoride are fewer cavities and less severe cavities, less need for fillings and tooth extractions, and less pain and suffering associated with tooth decay. In fact, given the dramatic decline in tooth decay during the past 60 years, the Centers for Disease Control and Prevention (CDC) named water fluoridation one of Ten Great Public Health Interventions of the 20th Century.

Proponents of water fluoridation state that there is no risk to health when water fluoridation is monitored and remains at an appropriate concentration. The safety and effectiveness of fluoride at levels used in community water fluoridation has been thoroughly documented by scientific and public health organizations using scientific reviews and expert panels. Experts have weighed the findings and the quality of the available evidence and found that the weight of peer-reviewed scientific evidence does not support an association between water fluoridation and any adverse health effect or systemic disorders.

Supporters of water fluoridation state that it is important to have fluoride in drinking water in addition to the fluoride in toothpaste and fluoride treatments at the dentist’s office. The combined use of fluoride toothpaste and fluoridated water offers protection above using either separately. Toothpaste contains a higher concentration of fluoride but its effect wears off after an hour or two. Fluoride in drinking water is diluted, but it comes in contact with the teeth every time you drink tap water or beverages made from tap water, as well as foods prepared with tap water. This provides your teeth with a near continuous exposure to fluoride all day. Use of both fluoridated water and fluoridated toothpaste is recommended because fluoride in water and fluoride in toothpaste work differently to help prevent tooth decay. Water fluoridation is associated with an increased proportion of children without cavities and reduces the prevalence of tooth decay by 14.6% (2.25 teeth) compared to non-fluoridated areas. In Orillia, a town that has never fluoridated their water, elementary school children have the most severely decayed teeth among the 10 largest communities in Simcoe Muskoka, at a 66% higher decay rate than fluoridated areas in the region.

Proponents of water fluoridation agree that, of course, it does cost money to fluoridate the water but argue that the money is more than recouped in savings due to diminished tooth decay. A 2004 Canadian study concluded that every dollar invested in water fluoridation saves approximately $38 in dental treatment costs. Results from a Quebec study show the cost-effectiveness of water fluoridation even with the conservative estimation of a one percent decrease in cavities. Along the same lines, the United States Centers for Disease Control and Prevention found that the costs of restorative care to avert disease outweighed the cost of water fluoridation in towns of any size, even with the widespread availability of many forms of fluoride today. Under typical conditions, the annual per person cost savings in fluoridated communities is $16 in communities of fewer than 5,000 people and $19 dollars in communities of greater than 20,000 people. The lifetime cost of water fluoridation for one person is less than the cost of one dental filling.

Concerns Regarding Water Fluoridation

The cost of water fluoridation is estimated at $0.35 to $0.80 per person per year. This can add up to a large amount in big cities. For example, in Toronto water fluoridation costs $0.77 annually per person and has a population of approximately 2.5 million. Therefore, the cost of water fluoridation for the city of Toronto is approximately $1.9 Million. Critics of water fluoridation use this to advocate for non-fluoridated water, also citing alleged health risks such as dental and skeletal fluorosis, cancer, bone fractures, and others. In younger children, fluorosis can cause discolouration of the enamel of the teeth when too much fluoride is ingested, but in most cases fluorosis was caused by swallowing toothpaste.

Other critics of fluoridation say that they should have their own choice of when and how they receive fluoride. Fluoride is the only chemical added to water for the purpose of medical treatment. Opponents say that it is unethical to add fluoride to tap water because informed consent is standard practice for all medication, and one of the key reasons most of Western Europe has ruled against fluoridation. Also, the fluoride goes to everyone regardless of age, health or vulnerability. Some individuals are highly sensitive to low levels of fluorine, and other subsets of population are more vulnerable to fluoride’s toxicity. For example, black and Mexican children have higher rates of dental fluorosis than Caucasian children.

Opponents also state that fluoride has health consequences and is not an essential nutrient. No disease, not even tooth decay, is caused by “fluoride deficiency,” and fluoride can interfere with many important biological processes. The level of fluoride in mothers’ milk is very low and, therefore, a bottle-fed baby consuming fluoridated water can get up to 300 times more fluoride than a breast-fed baby. There are no benefits, only risks, for infants ingesting this heightened level of fluoride at an early age. Fluoride accumulates in the body because healthy adult kidneys excrete 50% to 60% of the fluoride ingested each day. The remainder accumulates in the body, largely in calcifying tissues such as the bones and pineal gland. Infants and children excrete less fluoride from their kidneys and take up to 80% of ingested fluoride into their bones. Animal experiments show that fluoride may accumulate in the brain and alter mental behaviour in a manner consistent with a neurotoxic agent. In total, there have now been over 100 animal experiments showing that fluoride can damage the brain and impact learning and behaviour. There have also now been 33 studies from China, Iran, India and Mexico that have reported an association between fluoride exposure and reduced IQ and one of these studies indicates that even just moderate levels of fluorine exposure (e.g., 0.9 ppm in the water) can exacerbate the neurological defects of iodine deficiency. Critics of fluoridation say fluoride may also cause non-IQ neurotoxic effects, arthritic symptoms, bone cancer, reproductive problems, and may affect the pineal gland, thyroid function, and may damage bone and increase hip fractures in the elderly. There is no margin of safety for several health effects.

Furthermore, critics remind people that the benefit is topical, not systemic. There is no need to swallow fluoride to protect teeth. Since the purported benefit of fluoride is topical, and the risks are systemic, it makes more sense to deliver the fluoride directly to the tooth in the form of toothpaste. A multi-million dollar, U.S. National Institutes of Health (NIH)-funded study found no significant relationship between tooth decay and fluoride intake among children.

Some opponents further argue that the chemicals used to fluoridate water are not pharmaceutical grade. Silicon fluorides have not been tested comprehensively and may increase uptake into children’s blood. Furthermore, fluoride may leach lead from pipes, brass fittings, and soldered joints. As a result of all of these concerns, an increasing number of scientists oppose fluoride.

What Can You Do If Your Community Adds Fluoride to the Tap Water and You Do Not Want to Consume Water With Fluoride?

Obviously, purchasing bottled water which contains less or no fluoride would be one option. Most brands of spring water contain very low levels of fluoride. However, bottled water commercializes a public good which is necessary for life and should be available at minimal cost to everyone. Also, it takes oil to make water bottles and many end up in the landfill (read our Bottled Water fact sheet for more information). The three types of filters that can remove fluoride are reverse osmosis, deionizers (which use ion-exchange resins), and activated alumina. Each of these filters should be able to remove about 90% of the fluoride. By contrast, “activated carbon” filters do not remove fluoride. If you choose to use home water treatment, make sure that the filter you use is certified to address your concerns. Another way to avoid fluoride from the tap is to purchase a distillation unit. Water distillation will remove most, if not all, of the fluoride. The price for a distillation unit varies widely depending on the size. Small counter-top units cost as little as $200, while large units can exceed $1,000.

The Future of Water Fluoridation in Canada

Studying the effectiveness of fluoridation is becoming more difficult when comparing water fluoridated communities to non-fluoridated communities. With increased access to dental fluoridation, fluoridated toothpastes, and naturally occurring fluoridated water, many factors could be the reason for lower cavities and tooth decay occurrences. With increased use of fluoridated toothpastes and dental fluoridation, and critics voicing multiple concerns, the question of whether fluoride still needs to be added to tap water is being raised. Some cities are holding or have held referendums to let their citizens decide whether water should be fluoridated. For example, a Prince George referendum has been called for October 2014 to ask citizens if they would like to continue to fluoridate their community water systems. In April 2014 Estevan citizens voted to continue adding fluoride to their drinking water. Fluoride is proven to be vital to dental health but the question of whether it should be added to tap water is being pondered by an increasing number of people.

Please help us to continue to work towards our mission of educating the leaders of today and tomorrow about drinking water quality issues and realizing our goal of safe drinking water being available to every Canadian. Please chip in $5 today, or donate $20 or more and receive an Official Donation Receipt for Income Tax Purposes.


Campaign for Dental Health. 2014. What Do Critics Say?

Centers for Disease Control and Prevention. December 6, 2013. Community Water Fluoridation.

Colgate Oral and Dental Health Resource Center. October 1, 2013. Fluoride And Your Teeth.

Fluoride Action Network. Retrieved August 14, 2014. 50 Reasons to Oppose Fluoridation.

Fluoride Action Network. Retrieved August 15, 2014. Top 10 Ways To Reduce Fluoride Exposure.

Fluoride Exposed. Retrieved January 3, 2018. Does Fluoride Prevent Cavities? https://fluorideexposed.org/does-fluoride-prevent-cavities

Fluoride Exposed. Retrieved January 3, 2018. Modern miracles: 10 ways we beat disease over the last century. https://fluorideexposed.org/fluoridation-one-of-10-ways-we-beat-disease#

Journal of the Canadian Dental Association. July/August 2009. Water Fluoridation in Canada: Past and Present.

Wellesley Institute. September 2013. The Real Cost of Removing Water Fluoridation: A Health Equity Impact Assessment.