The mayor of Huntsville says he had an epiphany two months ago that changed his position on whether communities should add fluoride to municipal water systems.

“I had always subscribed to the theory of fluoride being a good thing in the drinking water,” said Claude Doughty, a retired dentist.

“It took six months for me to switch my position. I did a lot of reading and thinking and came to the conclusion that fluoride’s best-before date had passed and it was time that it should come out of the drinking water.”

Municipalities have been “playing doctor,” he said, by deciding if fluoride — which he calls a medication — should be added to an entire community’s drinking water.

Down Highway 11 from Doughty’s community, in the Town of Bracebridge, Mayor Graydon Smith has a much different opinion on water fluoridation.

He said he trusts the advice of health units, federal health agencies and dentists that adding small amounts of fluoride to drinking water is a safe and effective way to prevent tooth decay.

“To me, it’s about digging a little deeper. It’s about real science. It’s about basing a decision on more than just emotion,” he said.

The District of Muskoka, which includes Huntsville, Bracebridge and four other communities, was thrust back into the water fluoridation debate — a conversation that is now taking place in Owen Sound — after the council of the district, which operates the region’s water systems, voted 10-9 in November to end the practice.

The decision set Feb. 3, 2014, as the end date for regional water fluoridation. But the district council later gave each lower-tier municipality the power to keep fluoride in their water.

Huntsville and Lake of Bays both decided to stick with the district’s decision.

Bracebridge and the other three municipalities approved motions to keep fluoride in their water.

The situation in Muskoka — and the contrasting views of two of the region’s mayors — is just one illustration of how polarizing and contentious the water fluoridation issue remains today.

It’s a debate that has played out in council chambers, community centres and auditoriums across Ontario — and in many parts of the world — over many decades.

In Owen Sound, a committee is now studying the issue and is expected to decide next month whether or not to recommend that city council ask voters in October if the practice — in place for nearly 50 years — should cease.

Water fluoridation is lauded by the World Health Organization, Health Canada, the American Centers for Disease Control, the Canadian Dental Association and medical officers of health in Ontario as an effective way to prevent tooth decay.

“There is so much evidence that it is safe,” said Grey-Bruce’s medical officer of health Dr. Hazel Lynn.

But the anti-fluoridation movement continues to grow and has spawned international, national and community action groups.

Opponents say water fluoridation is an outdated, ineffective practice that poses a threat to human health and should not be forced on the masses.

“It’s a lousy, lousy medical practice. It should never have started,” said Paul Connett, executive director of the Fluoride Action Network. “The risks greatly outweigh the benefits.”

Owen Sound electors voted in 1965 to begin fluoridating the city’s water supply. The practice was upheld in 1997 following a second plebiscite.

Since the referendum upheld the fluoridation, another plebiscite is needed before it can be stopped, according to Ontario’s Fluoridation Act.

The city’s operation advisory committee recently decided to dust off the long-dormant debate and re-examine the issue in light of continued opposition in the province to the practice.

Dozens of Ontario communities have either rejected introducing water fluoridation — Orillia did so in 2012, Thunder Bay in 2009 and Welland in 2008 — or voted to remove fluoride from their drinking water — like Windsor did in 2013, Orillia in 2011 and Waterloo in 2010.

In almost every case, councils went against the advice of local dentists and public health experts. Community action groups against fluoridation were formed in several of those municipalities before the councils voted.

Some communities, like London and Cornwall, have stood behind their decisions to fluoridate water.

People on the pro-fluoride side of the debate say their arguments are based on solid scientific research.

Opponents, meanwhile, say the same thing and can list off studies and expert opinions to back their claims.

However, Lynn said no peer-reviewed scientific evidence exists that links fluoride, in the amount currently added to Owen Sound’s water supply, to illness or disease.

Communities that add fluoride to their water do not have higher rates of cancer, thyroid disease, dementia, lowered IQ or any other medical condition than do towns and cities that don’t fluoridate their water, she said.

Water fluoridation benefits the common good, Lynn said.

People living in poverty — who cannot afford to see a dentist or do not use fluoridated toothpaste — are impacted the most when fluoride is removed from a municipal water system, she said. Nearly one-quarter of children under age six in Owen Sound live in poverty.

Water fluoridation can reduce cavities in a community’s population by 60%, she said.

Connett, a retired environmental chemistry professor who helped create the Fluoride Action Network in 2000, said evidence that fluoride in drinking water prevents cavities is extremely weak.

Water fluoridation marks the first time drinking water has been used to treat humans, he said. The amount of fluoridated water people consume cannot be controlled and it is delivered to everyone, regardless of a person’s age or health. It violates peoples’ right to choose.

Fluoride can damage the brain, affect thyroid function, cause bone cancer and arthritic symptoms and lead to other health problems, he said.

“It is a known toxic substance,” Connett said.

Mayor Doughty, who once served as president of the Royal College of Dental Surgeons, said people can now get fluoride from toothpaste, foods and supplements.

Fluoride from drinking water adds up in waterways and can hurt the environment, he said.

It’s simply not worth the risk to the environment or human health, he said, to continue adding it to drinking water.

“We really don’t have the moral authority to be putting this kind of substance in peoples’ drinking water,” he said.

Mayor Smith, on the other hand, said it seemed like only a vocal minority of people in his community opposed water fluoridation.

It is important to base the decision on science and the opinions of institutions the public trusts, he said.

“I’m glad as a parent of two young kids that my water is fluoridated,” he said.