CALGARY – City councillors are reviewing the findings of a report on the potential pros and cons of reintroducing fluoride into drinking water.

After fluoride was removed in 2011 in an effort to save $750,000 annually, the city is reconsidering its decision. 

In February, council voted in favour of commissioning the University of Calgary’s O’Brien Institute of Public Health (OIPH) to conduct a study on the effects of fluoridation. 

"We were asked to have conversations with people who are in an advocacy position and that was really eye-opening because you gain respect for the way people are considering evidence," said Willian Ghal, scientific director with OIPH.

OIPH researchers provided councillors with information on Tuesday, but not recommendations, although its study shows there are significant benefits to reintroducing fluoride. 

For a city the size of Calgary, OIPH found that a community water fluoride program is expected to result in a reduction of three million cases of decayed, missing and filled teeth over the next 20 years. That equates to roughly two incidents per person on average. 

The report also found a 44 per cent relative reduction in baby teeth affected by cavities, a 37 per cent reduction in children’s permanent teeth affected by cavities and a 50 per cent lower rates of hospital admissions for surgical treatment for tooth decay. 

OIPH additionally reports a 35 per cent reduction in the number of adult teeth affected by decay and cavities. It protects a reduction of an average of just one cavity per person over a 40 year time span. 

Mayor Nenshi agrees it's important to listen to these figures. 

"My own position on this is clear, I’ve always been in favour of science-based, evidence-based decision making," he said. "It will be interesting to see what council thinks about something that’s been driven by many, many citizens who want to re-open this conversation."

As for the harmful effects of fluoride, OIPH points to evidence suggesting minor impacts on thyroid function. There’s also consistent evidence the addition of fluoride results in fluorosis, the discolouration of adolescent teeth during formation.

The report points to some new emerging evidence that fluoride exposure during pregnancy may be harmful to the brain development of children, although the claims remain unproven.

The city says the estimated cost to reintroduce fluoride is approximately $6 million to upgrade the dormant fluoridation system.

Council overall supported fluoride in water, but councillors say it will eventually come down to how much the city can afford, in terms of funding.

"If the province said, 'look as the people responsible for the health of Albertans, specifically Calgarians, we want to pay to fluoridate the water,' it would be a done deal," said Coun. Gian Carlo-Carra.

Coun. Evan Woolley agreed, saying it would be beneficial to Alberta in the long run.

"The city would be on the hook for the cost of this even though the financial benefits would be to the province," he said.

Ultimately, the city wants to hear from all Calgarians on the matter.