Fluoride will remain in Calgary's drinking water after city council voted down a motion to remove it.

A proposal to refer the motion for more study, including an assessment of whether a plebiscite could decide the contentious issue, was also rejected Tuesday.

Five aldermen supported the motion to remove the substance from Calgary's water supply in part to save money, but it was voted down 7-6.

Some of them questioned the cost — $600,000 a year to add fluoride to the water, plus as much as $5 million in mandatory upgrades to the fluoride systems at the city's water treatment plants — as well as the potential health concerns.

Ald. Dale Hodges, a veteran of several earlier fluoride debates, said it is not council's place to make the decision unilaterally.

"I think the issue should go to plebiscite whether you're in favour of fluoridation or not in favor of fluoridation. The issue has been a public issue for six times, has been back to council here six times in the last 35, 40 years," he said.

Ald. Druh Farrell, who would like to see fluoride removed from Calgary's water, said she will push for yet another plebiscite, which could be put on the ballot for the next civic election in October 2010.

Studies debate health benefits

The city has held six plebiscites on the issue, with 53 per cent of Calgarians voting in 1989 in favour of adding fluoride to the water supply to help prevent tooth decay.

The most recent plebiscite was in 1998, when 55 per cent of Calgarians who voted chose to keep fluoride in drinking water.

But new studies have come up over the years questioning the benefits of adding fluoride to water.

Last year, a panel of experts recommended Health Canada lower fluoride levels in drinking water to 0.7 mg/L to limit exposure in children and infants, who are particularly vulnerable if they ingest powdered infant formula reconstituted with fluoridated water.

This level, they say, balances the need for dental cavity protection with the risk of dental fluorosis, which leads to staining or pitting of the teeth if too much fluoride is ingested.

The Canadian Dental Association defended fluoridation, saying it benefits all residents in a community, regardless of age, socioeconomic status, education or employment.