Understanding Public Decision-Making on Community Water Fluoridation

Since 1953, the Canadian Dental Association (CDA) has supported the practice of community water fluoridation (CWF) as a safe, effective and economical means of preventing tooth decay in all age groups. Despite support from public health experts and organizations, CWF is meeting stiff opposition at the local level across Canada. Since 2005 more than 30 communities have voted to discontinue fluoridation of their municipal water supplies, including Calgary, Waterloo, and Windsor.¹

When local authorities are faced with the question of CWF, dentists and professional associations are called upon to advocate for the practice of water fluoridation. Many dentists have spoken in favour of fluoridation during public debates, bringing the best available evidence and their own clinical experiences to the discussions, yet have often been frustrated in their attempts to convince local politicians or the public of the benefits of CWF.

According to Dr. Euan Swan, CDA manager of dental programs, scientific evidence is only one factor that will influence the public when it comes to CWF—but it may not be the most important factor. “The public draws on emotional or values-based factors when it comes to supporting or opposing CWF. Fundamentally, it comes down to an issue of trust,” says Dr. Swan. “To engage the public on CWF, dentists and other public health experts should acknowledge the public’s safety concerns and address them. If the public is unable to evaluate the credibility of evidence presented to them, whether it’s in favour of CWF or opposed to it, they may choose the option of least change—if in doubt, leave it out.”

To better understand why community decisions around CWF can sometimes run counter to the recommendations of public health authorities, Dr. Swan points to a 2007 study² sponsored by the Dental Health Foundation (now the Center for Oral Health) and the School of Public Health at the University of California Berkeley. The study examined the decision-making process of San Diego residents when faced with the question of whether or not the city should fluoridate its water. Although the report found that supporters and opponents of CWF consistently agreed on a number of key points, mistrust developed when people felt that experts advocated strongly for one viewpoint or outcome and corrected factual misunderstandings without addressing deeper public concerns. The report notes that, “Participants tended to view such advocacy strategies as manipulative and one-sided and, when presented with what they saw as ‘spin vs. spin,’ those without strong pre-existing opinions said that they had no good way of assessing which arguments were more credible.”

The report also concluded that, rather than trying to convince people of the benefits of CWF, it is more important to openly address concerns about risk. In Windsor, at least 1 city councillor who voted against CWF felt that the potential harms—including questions about the lack of clinical trials examining the potential benefits and harms of fluoridated water—were not effectively addressed. In an interview on TVO’s The Agenda with Steve Paikin, councillor Bill Marra expressed his view that, “...the medical community didn’t really do a very good job responding to those (safety-related) concerns and questions. So it automatically raises doubts. It raises a red flag.”

Understanding public concern and building from common ground when engaging the public can effectively build trust. “Trust is difficult to build once a CWF campaign is already underway,” adds Dr. Swan. The report found that although public trust in scientific and medical organizations cannot be relied on, people’s trust in their own practitioners remained high. “So, discussing CWF with your patients may help build public support for CWF.”