The State of Community Water Fluoridation across Canada

• 2022 Report
• Prepared by the Office of the Chief Dental Officer of Canada, Public Health Agency of Canada

• Introduction
• Methodological remarks
• Results
  • Table 1: Provincial and Territorial estimates for community water fluoridation systems coverage, 2022
  • Figure 1: Provincial and Territorial estimates of fluoridated water systems coverage in Canada
  • Table 2: Provincial and Territorial estimates for coverage of wells with naturally occurring fluoride, 2022
  • Table 3: Provincial and Territorial estimates for total community water fluoridation systems coverage, 2022
  • Table 4: Comparing changes in community water fluoridation status between 2017 and 2022
  • Table 5: Provincial and Territorial estimates for community water fluoridation systems coverage, 2007, 2012, 2017 and 2022
  • Table 6a: Estimates of CWF systems coverage of Indigenous communities across the Provinces, 2022
  • Table 6b: Estimates of CWF systems coverage of Indigenous communities across the Territories, 2022
  • Table 7: Status of National Defence Canadian Forces Base (CFB) water fluoridation coverage, 2017

Introduction

Fluoride is a naturally occurring mineral present in nearly all water sources. It is naturally released from rocks into the soil, water, and air. Drinking water that contains fluoride has long been associated with reduced tooth decay. In 1909, two U.S. dentists F. McKay and G. V. Black initiated a 15-year follow-up study in one Colorado town and observed very low caries rates among residents who had access to drinking water with a naturally high level of fluoride. Since then, numerous scientific findings have corroborated the preventive effect of fluoride on tooth decay. By exposing the teeth to a constant low level of fluoride, it helps reduce the cavity-causing effect of foods and bacteria. Fluoride molecules create stronger teeth by hardening tooth enamel, contributing to tooth surface re-mineralization and deterring oral bacteria^{Footnote 1}.

Community water fluoridation (CWF) is the process of monitoring and adjusting the fluoride level in drinking water to the optimal level for caries prevention. Water fluoridation has been instrumental in the overall global reduction in dental caries, and many communities around the world have access to CWF. The U.S. Centre for Disease Control considers CWF as one of the ten greatest public health achievements of the 20th century^{Footnote 2}.

CWF is the most cost effective and equitable method to deliver fluoride to the population. This population-based preventive intervention contributes to oral health equity by overcoming common social determinants of health including age, education, income, and access to professional dental care. Several reports indicate CWF yields a high return on investment that increases according to community population size, with a per capita annual benefit ranging from $5.49 to $93.19^{Footnote 3} per dollar invested.

Further, CWF is endorsed by major public health bodies around the world, including the World Health Organization, the Canadian Dental Association, and the Public Health Agency of Canada (PHAC). The Chief Dental Officer of Canada and the Chief Public Health Officer of Canada have co-signed the PHAC Position Statement on CWF.

From a public health perspective, CWF is associated with an approximate 25% reduction in tooth decay in children and adults^{Footnote 4}. The recommended fluoride concentration for caries prevention in Canada (called the optimal level) is 0.7 milligrams/liter (mg/L)^{Footnote 5},^{Footnote 6},^{Footnote 7} or 0.7 parts per million (ppm).

In 2017, approximately 13.9 million Canadians (38.7%)^{Footnote 8} had access to CWF through water systems, leaving the majority of Canadians not benefitting from the caries protective effect of fluoridated drinking water. In 2022, there are around 14.4 million Canadians (38.8%) who benefit from CWF.

In spite of its robust policy and scientific endorsement, a number of municipalities across Canada have discontinued CWF since 2017 (see Table 4). The rationale for the decision to discontinue CWF varies by jurisdiction and may be influenced by different factors, including community concern over putative health effects^{Footnote 9} and technical/financial aspects thought to be related to the delivery of fluoride. This discontinuation of CWF in some communities and the relative distribution of the population in areas without fluoride treated water systems impacts the percentage of the population which currently has access to fluoridated water. Thus, even though the total population for the country has increased and there are slight increases in CWF estimates for the majority of Provinces and Territories, Table 5 shows that the overall estimate of CWF coverage across Canada has remained fairly steady since 2017.

To document the situation from a national perspective, the Office of the Chief Dental Officer of Canada (OCDOC), working closely with the Federal-Provincial-Territorial Dental Directors Working Group (FPTDDWG) and the Federal Dental Network (FDN), has taken a leadership role to periodically update the data on the state of CWF across Canada. The OCDOC has carried out this exercise in 2007, 2012, 2017 and 2022. In addition to estimating the population's access to optimal levels of fluoride through a community water supply, the 2017 round also included data on population access to well water supplies that contained naturally occurring fluoride and estimates of access to fluoridated drinking water in Indigenous communities. The additional element provided in this 2022 report is the status of National Defence Canadian Forces Bases water fluoridation coverage, 2017.

Methodological remarks

Members of the FPTDDWG provided data on drinking water fluoridation status for their respective Province/Territory. They gathered this information from their respective Provincial/Territorial environment or health ministries.

Provincial/Territorial estimates for total CWF coverage were calculated using the ratio of the population receiving CWF to the total population. In most cases, the data provided was from 2021. Therefore, Provincial/Territorial total populations were derived from the Statistics Canada 2021 census data^{Footnote 10}. The CWF coverage data was provided, as mentioned, by Provincial/Territorial environment or health ministries through their FPTDDWG member, as well as by the Department of National Defence representative of the FDN. One of the limitations of this report is that discrepancies exist in the timing of the data collection (anywhere between 2017 and 2022) across the Provinces/Territories and Canadian Armed Forces (CAF) Bases.

Given the difference in reporting systems across jurisdictions, variations in the quality of the data and in the level of detail and completeness of the information were also observed. While some Provinces/Territories were able to provide information on all communities, including data for both fluoride treated water systems and wells with naturally occurring fluoride, other jurisdictions were only able to provide information on communities with CWF systems. Further, several Provinces/Territories noted a variety of difficulties with obtaining CWF data as a result of resources having been diverted to support Canada's response to the COVID-19 pandemic.

Data collection related to well water supplies with naturally occurring fluoride was also challenging: data were incomplete for some Provinces/Territories because they have not historically collected this type of information.

Estimating the Provincial/Territorial population receiving well water with naturally occurring fluoride added another layer of complexity. Many wells are located on private property and thus are not within the municipal, P/T or federal government's jurisdiction to monitor. This situation was particularly true for remote and rural communities.

The level of naturally occurring fluoride in well water is often unknown, making it challenging to determine whether residents are benefiting from exposure at the optimal fluoride level through this source. Moreover, some communities were served by multiple well water sources at different periods of time, which may have resulted in some communities receiving intermittent fluoridated water.

The current status of CWF in Indigenous communities across the Provinces was obtained from Indigenous Services Canada, First Nations and Inuit Health Branch, Environmental Public Health Division (2022 data). Territorial Indigenous community population data were obtained from the respective FPTDDWG member and Statistics Canada, 2021 Census of Population data^{Footnote 11}.

Results

This report includes seven tables and one figure:

• Table 1 presents Provincial and Territorial estimates for community water fluoridation systems coverage, 2022.
• Figure 1 presents Provincial and Territorial estimates of fluoridated water systems coverage across Canada.
• Table 2 presents Provincial and Territorial estimates for coverage of wells with naturally occurring fluoride, 2022.
• Table 3 presents Provincial and Territorial estimates for total community water fluoridation systems coverage, 2022.
• Table 4 compares changes in community water fluoridation status between 2017 and 2022.
• Table 5 presents changes in Provincial and Territorial estimates for community water fluoridation systems coverage for 2007, 2012, 2017 and 2022.
• Table 6a presents estimates of CWF systems coverage in Indigenous communities across the Provinces, 2022.
• Table 6b presents estimates of CWF systems coverage in Indigenous communities across the Territories, 2022.
• Table 7 presents the status of National Defence Canadian Forces Base (CFB) water fluoridation coverage, 2017.

Figure 1 - Text Description

Fluoridated Water Systems Coverage in Canada, 2022

Province/Territory	Percentage
British Columbia	1.5%
Alberta	43.0%
Saskatchewan	40.4%
Manitoba	68.3%
Ontario	73.2%
Quebec	1.0%
New Brunswick	1.1%
Nova Scotia	50.4%
Prince Edward Island	25.1%
Newfoundland and Labrador	0.0%
Nunavut	27.7%
Northwest Territories	68.6%
Yukon	0.0%
Across Canada	38.8%

The map includes a legend that divides fluoridation status into three different ranges (0 – 25%; 26 – 50% and 51 – 75%), which provides a national perspective of fluoridated water systems coverage across Canada.

% water systems coverage - Province/Territory

• 0 – 25%
  • BC
  • QB
  • NB
  • NL
  • YT
• 26 – 50%
  • AB
  • SK
  • NU
  • NS
  • PE
• 51 – 75%
  • NT
  • MB
  • ON

This mapping of Provincial and Territorial estimates for fluoridated water systems coverage across Canada (2022) draws on data presented in Table 1. The map does not include the estimates for coverage of wells because these naturally occurring fluoride levels are often unknown. As such, the focus is on fluoride treated water systems from which people benefit from the optimal level of fluoride to prevent tooth decay.

The population data provided for Table 6a may overestimate the reality for some Indigenous communities. For example, some homes within Indigenous communities with fluoridated water systems may be on private wells. Alternatively, several communities may have Municipal Transfer Service Agreements, but the population served by these fluoridated water systems may be smaller than the total population of that Indigenous community. The First Nations of Sipekne'katik, NS and Mushuau Innu, NL are both served by Community Water Systems which are owned, operated and located within each of these communities; their fluoride sources are both from groundwater and are naturally occurring. As such, neither of these Indigenous communities have been included in Table 6a, which presents estimates for fluoride treated water systems coverage in Indigenous communities across the Provinces.

See Table 6b for estimates of access to fluoride treated water systems for Indigenous communities within Nunavut, Northwest Territories and Yukon.

As Nunavut, Northwest Territories and Yukon do not have "Reserves" per se, these territories are not included in Table 6a. We consequently provide estimates for fluoride treated water system coverage of Indigenous communities within each of these three jurisdictions as a ratio of the population of Indigenous communities with fluoride treated water systems over the total Indigenous population of each territory (Table 6b).

While the population of CAF members assigned to each base would help provide estimates of access to fluoridated water across all CAF bases, these data points would be largely overestimated because the majority of CAF members live off base and in the surrounding communities. As such, the fluoridation status (fluoride treated water, naturally occurring fluoride, unknown fluoride level) of each CAF base across Canada is provided in Table 7. This fluoridation status is based on CAF's review in 2017 of drinking water sources for each base, including the existence/use of water treatment plants and whether or not there was fluoride testing/monitoring.