Fluoride in people living in Canada

Learn about human biomonitoring of fluoride in Canada.

On this page

• About fluoride
• Data sources for fluoride biomonitoring
• Results of fluoride biomonitoring
• Related links
• How to cite this page

About fluoride

Fluoride is a mineral found naturally in the environment in its inorganic form. Fluoride compounds are also used in industrial processes to make materials such as:

• glass
• glue and adhesives
• steel and aluminum
• pesticides and fertilizers

Fluoride compounds are often added to drinking water and dental products to help prevent dental cavities. Fluoride can also occur naturally in drinking water, especially from groundwater sources.

People are exposed to fluoride by:

• using dental products containing fluoride (like fluoridated toothpaste)
• eating certain foods
• drinking water and other beverages

People are exposed to much smaller amounts from soil and air.

Fluoride is absorbed in the body after exposure. Some of it stays in bones and teeth and the rest is excreted in urine. Fluoride can be measured in a urine sample. The presence of fluoride in urine reflects recent exposure.

Potential health effects of fluoride

Fluoride helps prevent tooth decay, a common and serious disease in Canada. Studies show that fluoride can:

• strengthen tooth enamel
• lower the amount of acid in your mouth
• rebuild minerals that make teeth stronger

In moderate amounts, fluoride is good for teeth. However, too much fluoride may cause negative effects on:

• teeth (dental fluorosis)
• bones (skeletal fluorosis)
• cognitive function (IQ)

Dental fluorosis affects tooth enamel. It is caused by consuming too much fluoride over a long period during tooth formation. The effects range from mild discolouration to enamel pitting. Moderate and severe dental fluorosis are rare in Canada.

Skeletal fluorosis is caused by consuming high levels of fluoride regularly over a long period of time. It can cause dense bones, joint pain and limited range of joint movement. Skeletal fluorosis is extremely rare in Canada.

There is uncertainty about the effects of consuming low levels of fluoride. The science is evolving and researchers continue to study how fluoride affects cognitive function, including brain development and learning, especially in children.

The International Agency for Research on Cancer found there isn't enough information to determine whether fluoride in drinking water can cause cancer in people.

The presence of a substance in your body doesn't mean it will affect your health.

Managing fluoride in Canada

We have supported community water fluoridation to prevent tooth decay. This is the process of monitoring and adjusting the fluoride level in drinking water to the optimal level for preventing tooth decay.

In addition, we have:

• established guidelines for fluoride in drinking water and soil
• provided guidelines on fluoride toothpaste usage tailored to children's age and oral health needs
• added fluoride-containing substances to the list of ingredients that are restricted for use in cosmetic products
• limited the allowable concentration of fluoride in some foods and prepackaged water and ice
• identified inorganic fluorides as toxic under the Canadian Environmental Protection Act, 1999 due to concerns for the environment
• developed risk management tools to reduce the releases of inorganic fluorides from steel manufacturing facilities

We continue to monitor and assess fluoride-containing substances.

Data sources for fluoride biomonitoring

This page presents human biomonitoring data from the:

• Canadian Health Measures Survey (CHMS)
• Maternal-Infant Research on Environmental Chemicals (MIREC) study
• MIREC-Child Development study (MIREC-CD Plus)

You can access more results for fluoride and other chemicals in the Canadian population through the Canadian biomonitoring dashboard.

Overview of biomonitoring initiatives for urinary fluoride in Canada

We wish to acknowledge all participants, including First Nations, Inuit and Métis peoples, who took part in the biomonitoring studies.

Results of fluoride biomonitoring

Fluoride enters drinking water from natural sources and through community water fluoridation. Natural fluoride levels and water fluoridation status vary across Canada. Around 40% of people living in Canada have access to community-fluoridated water. Fluoride biomonitoring results are presented by community water fluoridation status.

Levels in the Canadian population, by fluoridation status

Average fluoride levels were higher in people living in fluoridated communities than in people living in non-fluoridated communities. From 2009 to 2019, average levels of fluoride were relatively unchanged in both groups.

Text description

Collection period	Fluoridation status	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	Non-fluoridated	0.37	0.34–0.41
2009 to 2011	Fluoridated	0.64	0.55–0.73
2012 to 2013	Non-fluoridated	0.35	0.32–0.39
2012 to 2013	Fluoridated	0.58	0.49–0.69
2014 to 2015	Non-fluoridated	0.37	0.33–0.42
2014 to 2015	Fluoridated	0.66	0.48–0.91
2016 to 2017	Non-fluoridated	0.36	0.33–0.40
2016 to 2017	Fluoridated	0.67	0.47–0.95
2018 to 2019	Non-fluoridated	0.37	0.35–0.40
2018 to 2019	Fluoridated	0.70	0.62–0.79

Levels in the Canadian population, by age group and fluoridation status

Average fluoride levels were similar across age groups. This was found in people living in both fluoridated and non-fluoridated communities.

Text description

Non-fluoridated

Collection period	Age group (years)	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	3 to 5	0.37	0.29–0.47
2009 to 2011	6 to 11	0.33	0.30–0.38
2009 to 2011	12 to 19	0.30	0.27–0.33
2009 to 2011	20 to 39	0.40	0.35–0.47
2009 to 2011	40 to 59	0.36	0.31–0.42
2009 to 2011	60 to 79	0.41	0.33–0.50
2012 to 2013	3 to 5	0.34	0.28–0.41
2012 to 2013	6 to 11	0.34	0.29–0.39
2012 to 2013	12 to 19	0.32	0.28–0.36
2012 to 2013	20 to 39	0.34	0.29–0.40
2012 to 2013	40 to 59	0.37	0.30–0.45
2012 to 2013	60 to 79	0.36	0.29–0.45
2014 to 2015	3 to 5	0.33	0.28–0.40
2014 to 2015	6 to 11	0.36	0.31–0.42
2014 to 2015	12 to 19	0.36	0.32–0.39
2014 to 2015	20 to 39	0.36	0.29–0.45
2014 to 2015	40 to 59	0.35	0.30–0.42
2014 to 2015	60 to 79	0.42	0.36–0.49
2016 to 2017	3 to 5	0.39	0.31–0.49
2016 to 2017	6 to 11	0.38	0.34–0.43
2016 to 2017	12 to 19	0.37	0.31–0.44
2016 to 2017	20 to 39	0.34	0.28–0.41
2016 to 2017	40 to 59	0.35	0.31–0.39
2016 to 2017	60 to 79	0.40	0.35–0.46
2018 to 2019	3 to 5	0.37	0.28–0.50
2018 to 2019	6 to 11	0.36	0.31–0.43
2018 to 2019	12 to 19	0.35	0.29–0.42
2018 to 2019	20 to 39	0.36	0.27–0.49
2018 to 2019	40 to 59	0.39	0.32–0.47
2018 to 2019	60 to 79	0.38	0.32–0.45

Fluoridated

Collection period	Age group (years)	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	3 to 5	0.56	0.48–0.66
2009 to 2011	6 to 11	0.68	0.60–0.79
2009 to 2011	12 to 19	0.53	0.44–0.64
2009 to 2011	20 to 39	0.63	0.52–0.76
2009 to 2011	40 to 59	0.70	0.57–0.85
2009 to 2011	60 to 79	0.60	0.50–0.71
2012 to 2013	3 to 5	0.49	0.42–0.56
2012 to 2013	6 to 11	0.50	0.44–0.56
2012 to 2013	12 to 19	0.52	0.42–0.63
2012 to 2013	20 to 39	0.58	0.38–0.89
2012 to 2013	40 to 59	0.63	0.51–0.77
2012 to 2013	60 to 79	0.58	0.47–0.71
2014 to 2015	3 to 5	0.56	0.46–0.69
2014 to 2015	6 to 11	0.65	0.48–0.88
2014 to 2015	12 to 19	0.52	0.38–0.70
2014 to 2015	20 to 39	0.65	0.41–1.00
2014 to 2015	40 to 59	0.72	0.48–1.10
2014 to 2015	60 to 79	0.70	0.48–1.00
2016 to 2017	3 to 5	0.57	0.38–0.86
2016 to 2017	6 to 11	0.57	0.37–0.87
2016 to 2017	12 to 19	0.53	0.38–0.74
2016 to 2017	20 to 39	0.70	0.50–0.99
2016 to 2017	40 to 59	0.69	0.43–1.10
2016 to 2017	60 to 79	0.70	0.48–1.00
2018 to 2019	3 to 5	0.66	0.51–0.84
2018 to 2019	6 to 11	0.62	0.47–0.83
2018 to 2019	12 to 19	0.59	0.45–0.76
2018 to 2019	20 to 39	0.77	0.65–0.92
2018 to 2019	40 to 59	0.73	0.61–0.86
2018 to 2019	60 to 79	0.64	0.46–0.90

Levels in the Canadian population, by sex and fluoridation status

Average fluoride levels were similar between sexes. This was found in people living in both fluoridated and non-fluoridated communities.

Text description

Non-fluoridated

Collection period	Sex	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	Females	0.35	0.31–0.41
2009 to 2011	Males	0.39	0.35–0.44
2012 to 2013	Females	0.35	0.29–0.41
2012 to 2013	Males	0.36	0.32–0.40
2014 to 2015	Females	0.39	0.33–0.45
2014 to 2015	Males	0.35	0.32–0.39
2016 to 2017	Females	0.36	0.32–0.41
2016 to 2017	Males	0.36	0.32–0.41
2018 to 2019	Females	0.38	0.32–0.45
2018 to 2019	Males	0.37	0.33–0.41

Fluoridated

Collection period	Sex	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	Females	0.60	0.51–0.70
2009 to 2011	Males	0.68	0.57–0.80
2012 to 2013	Females	0.57	0.47–0.70
2012 to 2013	Males	0.58	0.49–0.70
2014 to 2015	Females	0.66	0.51–0.83
2014 to 2015	Males	0.66	0.43–1.00
2016 to 2017	Females	0.72	0.53–0.98
2016 to 2017	Males	0.62	0.42–0.93
2018 to 2019	Females	0.68	0.58–0.81
2018 to 2019	Males	0.71	0.62–0.82

Levels in pregnant people in Canada, by fluoridation status

Average fluoride levels were similar between pregnant people from a multi-city Canadian cohort and people of child-bearing age (females aged 18 to 49 years) in the general population. This was found in both fluoridated and non-fluoridated communities.

Text description

Non-fluoridated

Collection period	Study	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	CHMS	0.38	0.34–0.42
2008 to 2011	MIREC	0.29	0.28–0.31

Fluoridated

Collection period	Study	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2009 to 2011	CHMS	0.67	0.55–0.81
2008 to 2011	MIREC	0.60	0.58–0.63

Levels in children in Canada, by fluoridation status

Average fluoride levels were similar between preschoolers (aged 3 to 5) in a cohort from several Canadian cities and those in the general population. This was found in both fluoridated and non-fluoridated communities.

Text description

Non-fluoridated

Collection period	Study	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2014 to 2015	CHMS	0.33	0.28–0.40
2013 to 2015	MIREC-CD Plus	0.30	0.27–0.33

Fluoridated

Collection period	Study	Geometric mean level (mg/L)	95% confidence interval (mg/L)
2014 to 2015	CHMS	0.56	0.46–0.69
2013 to 2015	MIREC-CD Plus	0.46	0.42–0.50

Related links

• Human Biomonitoring of Environmental Chemicals
• Toxic substances list: inorganic fluorides
• Fluoride and oral health
• Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Fluoride
• Expert panel meeting on the health effects of fluoride in drinking water: Summary report
• The State of Community Water Fluoridation across Canada
• Community Water Fluoridation Programs: A Health Technology Assessment — Review of Dental Caries and Other Health Outcomes
• Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada
• Associations between Urinary, Dietary, and Water Fluoride Concentrations among Children in Mexico and Canada
• Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1–42

How to cite this page

Health Canada. 2025. Fluoride in people living in Canada. Ottawa, ON. Available: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/environmental-contaminants/human-biomonitoring-resources/fluoride-people-Canada.html

For more information, contact: biomonitoring-biosurveillance@hc-sc.gc.ca