STUART — City commissioners, uneasy about having to decide whether to fluoridate drinking water, agreed Monday night to leave it up to somebody else: city residents.

After listening to more than an hour and a half of public comment, commissioners voted 4-0 to put the matter to voters in the November election. In the meantime, the city will hold off on fluoridating drinking water, a measure that was approved four years ago by a previous commission.

Only two of the commissioners who took part in the original vote still sit on the board. Vice Mayor Jeffrey Krauskopf voted against fluoridation in 2003 and remains opposed. Michael Mortell, who favored fluoridation, still does. He was absent at Monday’s meeting.

The city has spent about $112,000 to design and build a system to deliver fluoride to drinking water, but recent public outcry prompted the commission to reconsider before turning on the valve.

In December, anti-fluoride activists convinced Martin County commissioners to overturn their decision to fluoridate. Many of the same opponents, including several people who live outside the city and Martin County, spoke Monday to the Stuart commission, saying fluoride increases the risks of bone cancer and can be poisonous to infants and people with thyroid conditions.

“We should have the freedom to choose whether we want to use fluoride,” said Carol Ann Leonard, who has a thyroid condition and lives just outside the city. “When I eat in a Stuart restaurant, I want to know that I’m not drinking fluoridated water and that my food was not cooked in fluoridated water.”

Fluoride proponents, who say it improves oral health, particularly in children, countered that many of the opponents’ claims were unfounded or taken out of context.

“You can choose to trust people who have spent their entire lives looking into this matter, or you can listen to people who are worried and afraid but are lifting statements to generate a conspiracy,” said David Boden, a periodontist who practices in Stuart and supports fluoridation.

Gene Rifkin, a former Stuart commissioner who voted in favor of fluoridation in 2003, accused fluoride opponents of “emotional blackmail” for making claims outside the meeting that commissioners would be recalled if they voted in favor of fluoridation. She recommended a referendum, but said “it seems almost ridiculous to have to do so.”

“I wish this issue wasn’t even before us,” Commissioner James Christie said. Despite the potential risks, Christie said he supports fluoridation, though to erase any idea that the commission was acting contrary to the interests of the public, Christie said he supports a public vote.

Commissioner Carol Waxler said she was undecided on the issue, but noted that many of the speakers at Monday’s meeting lived outside the city.

To give residents a say, she supported the ballot measure, as did Mayor Mary Hutchinson.

Should voters ultimately decide against fluoridation, the city would have to repay $59,000 in state grant money that helped pay for the fluoridation system’s design and construction. As a condition of the grant, the city also agreed to use a portion of that money to buy fluoride, but City Manager Dan Hudson said he would try to delay the city’s deadline to meet that obligation until the November election.