Phoenix this month will reconsider its stance on one of the most fervently debated public-health policies of the past 60 years: fluoridating drinking water.

City leaders voted in 1989 to add fluoride to the water supply. City Manager David Cavazos said he still remembers watching a dentist testify during a council hearing that the practice would help low-income residents without access to dental care.

“There wasn’t a single dentist in south Phoenix,” recalled Cavazos, who was then a staff member keeping meeting notes.

“And all these people had all these cavities, and if we put fluoride in the water, that would be a big way to correct it.”

Council members were swayed by the arguments, and fluoridation has remained a popular cavity-fighting tool. It has been endorsed by the Centers for Disease Control and Prevention, American Dental Association and every U.S. surgeon general for six decades.

But several City Council members say science can change, and they’re ready to revisit the issue. They argue that Phoenix must evaluate whether the $582,000 it spends per year on fluoride is still a wise investment.

Anti-fluoride activists have been flooding council members with calls and e-mails leading up to hearing on Tuesday, where members of the Transportation and Infrastructure Subcommittee will listen to expert presentations.

They will decide whether to forward the issue to the full council for a vote.

The council doesn’t appear to be leaning strongly in either direction. At least five members contacted by the Republic said they want to hear more about the impact and any scientific developments before making a determination to remove fluoride from the water system used by 1.4 million Phoenix residents.

“I’m waiting to hear significant proof that it has a really negative impact on the majority of people,” said Councilwoman Thelda Williams, who voted for fluoridation when she was on the council 23 years ago. “Every decade or two, we need to examine.”

Opponents say placing fluoride in water is equivalent to publicly prescribing a medicine without limiting its dosage. They argue that too much fluoride could lead to weight gain and muscle pain from thyroid problems, discoloration of teeth and other undiscovered side effects.

Dentists and medical professionals who have advocated fluoridation say it reduces cavities by up to 40 percent for areas with low levels of existing fluoride. The compound is naturally found in water supplies but can be artificially supplemented to help prevent tooth decay, they contend.

Cities across the state also add fluoride to their water supplies, including Chandler, Mesa, Glendale, Tempe and Peoria. A few have stopped the practice in recent years, including Flagstaff and Page.

Jody Clute, a Phoenix resident diagnosed with a thyroid problem that she believes is linked to fluoride, has led a grass-roots campaign to convince council members that fluoridation is hurting the public. Studies suggest fluoride inhibits the absorption of iodine, a mineral the thyroid needs to regulate the body’s metabolism.

Clute used Facebook to contact council members with her concerns, and a few agreed it was time to study the issue. She argues that dentists are not qualified to testify about any potential side effects fluoride may have outside of the mouth.

“It’s like you going to an orthopedist for skin cancer,” Clute said. “They are telling people to drink something that should be applied topically.”

Anti-fluoride activists say they worry that the council subcommittee hearing and evaluation process will not give equal time to both sides of the argument. They are hosting a debate 6 tonight at Phoenix College, 1202 W. Thomas Road. The group says Phoenix would not sponsor the debate.

Williams, who chairs the subcommittee, dismissed accusations that the city has not been transparent about the fluoride debate. She said the subcommittee will include a presentation from city staff followed by public comments, with each side being allotted equal time.

For many of the city’s elected leaders, fluoridation is an issue now because of the expense. Councilman Tom Simplot has questioned whether it’s a waste of taxpayer dollars if residents are drinking bottled water anyway. He said the city should re-evaluate because of both scientific challenges and the price tag.

However, Councilman Jim Waring said he’s leaning toward keeping fluoride in the city’s water. He said the health benefits outweigh the cost — about 39 cents per resident each year.

“I’m certainly happy to hear the testimony,” Waring said. “Obviously, it seems like the bulk of people … in this field support it.”