A group plans to petition the city to stop putting fluoride into the water in Winnipeg. They said the health benefits from fluoride are minimal and are worried about the side-effects of fluoridated water, but at least one Manitoba dentist said the group’s claims are off base.

The City of Winnipeg has been putting fluoride in the drinking water since the 1950s because it helps reduce tooth decay.

In 2011, they reduced the amount to 0.7 parts per million, which is well below the threshold Health Canada said could be dangerous.

“I don’t think any parts are OK. I don’t think it should be in there. There’s no reason for it to be in there,” said Dawn Fastabend from the group Fluoride Free Winnipeg. "It's a concern not just of myself but also my kids.”

She thinks even trace amounts of fluoride can increase the risk of cancer and other chronic illnesses.

Dr. Doug Brothwell, associate dean at the University of Manitoba’s faculty of dentistry, disagrees.

"We have extremely good evidence that there are no serious side-effects. No bad side-effects. No increases in cancer,” he said.

Brothwell said most people get enough fluoride from products like toothpaste and during regular visits to the dentist, but he said people living in poverty are less likely to get fluoride in those ways.

He said in impoverished communities, fluoridated water can reduce the number of cavities in children by up to 50 per cent.

"I don't think it's fair for the advantaged to make decisions that cause further problems for the disadvantaged. So, yes, fluoride should stay in the water,” he said.

Members of Fluoride Free Winnipeg said it should be up to individuals to decide if they want to consume fluoride.

They plan on petitioning the city to stop using fluoride altogether.

"I'm not saying ban it. I'm saying get it out of the water and give people the information that they need to make an informed decision,” said Josh Sigurdson from Fluoride Free Winnipeg.

- with a report from Ben Miljure