An emotional public health debate that shook Oneida a generation ago is about to reopen.

One of the most crowded public meetings in city history took place June 20, 1978, the last time the common council seriously considered fluoridating city water.

The proposal failed after a 3-3 vote in which then-Mayor Herb Brewer declined to cast a tiebreaking vote.

The audience was evenly divided, but opponents had a petition containing signatures from 800 people supporting their position.

Years later, Morrisville and a few Onondaga County communities added fluoride to their water supply. During that time, dozens of scientific studies were published on both sides of the fluoridation issue.

Fluoride is the active ingredient in most toothpastes. It aids in the prevention of tooth decay by binding with plaque that dissolves in saliva, creating an acid-resistant structure and helping to restore tooth minerals.

The American Dental Association touts recent studies that show fluoridated water helps reduce tooth decay in both children and adults by at least 17 percent, and says it may be the only method of prevention available for some low-income people who don’t regularly see a dentist.

Opponents fear fluoride potentially poisoning the human immune system if ingested.

The U.S. surgeon general recently trumpeted community fluoridation as one of the top 10 greatest disease prevention methods in the 20th century, prompting the dental health industry to pitch it to local governments once again.

On Tuesday, representatives from the Oneida-Madison County Preventative Dentistry Coalition, public water system experts and James Kinsella, a public health educator with the Madison County Department of Health, will state their case to the council during a 7 p.m. work session at City Hall.

But if and when the council takes action on this issue, it might be poised to leave such a monumental decision up to the public by way of referendum.

“It’s going to be a hot item. I know that from experience,” said Ward 4 Councilor Army Carinci, the only member of the board in office when that 1978 vote took place. “Let the people decide. I don’t like shoving things down people’s throats.”

Carinci voted “no” last time, saying the government didn’t have a right to determine what people should put in their bodies. But he maintained he trusted scientific evidence that defended public fluoridation as the most cost-effective way to prevent tooth decay.

Fluoridating Oneida’s water system, which also serves customers in Wampsville and Stockbridge and the neighboring Oneida County communities of Sherrill, Vernon and Verona, would cost between $50,000 and $100,000, according to Kinsella.

For municipal water supplies, the optimal dosage of fluoride is about 1 part per million. It would take 1.6 grams of fluoride in one ingestion to kill a 155-pound man, or 7,000 eight-ounce glasses of optimally fluorinated water.

Every municipal water system in Onondaga County is currently fluoridated, but the same cannot be said for most rural communities in Central New York. None are fluoridated in Cayuga County, for example, despite a strong push for it in Auburn.

In Oswego County, municipal water systems in Fulton and the villages of Sandy Creek, Mexico, Phoenix, Pulaski, Cleveland and Lacona are without fluoride. Residents in extremely rural towns in the northern part of the county, such as Redfield, Williamstown and Boylston, rely on wells.

And in Madison County, the villages of Cazenovia, Earlville and Munnsville, as well as several sparsely populated towns along and south of Route 20 that rely on wells, are without fluoridated water, while the towns of Canastota, Chittenango, Sullivan and Lenox have had their water fluoridated since 1976.

In New York state, 69.7 percent of public water supply systems are fluoridated. Nationwide, the figure is 62.1 percent, according to the National Oral Health Surveillance System.

In California, state law requires all water supplies serving more than 10,000 customers to be fluoridated.

“I think it’s pretty clear and supported by dental health organizations and governments that it’s the cheapest and most effective way to improve dental health,” Kinsella said. “Trust the professionals that you already trust.”

Donald Behr, who represents Oneida on the Madison County Board of Supervisors, is leading the charge to keep the city water supply fluoride-free. He’s been the staunchest and most vocal opponent since the city first explored the idea.

“There have been a lot more places that have come out against it, but they (proponents) don’t bother to mention it,” Behr said.

In 2000, a referendum for community fluoridation was defeated in Ithaca. Albany’s common council rejected proposals for fluoridation the same year.