BANGOR – The debate over adding fluoride to public drinking water supplies, a practice that gained broad national support in the 1950s and is still going strong today, never seems to be completely settled.

At this year’s November election, voters in two northern Maine communities found fluoride on their local ballots — one measure seeking to add the tooth-strengthening substance to the water system for the first time and the other looking to discontinue the practice. At least one other town is exploring whether to put its existing fluoride program on the ballot, perhaps as soon as next fall.

Just this week in Bangor, a local pediatrician advised the city council that one of the largest water utilities in Maine should discontinue its fluoridation program, which started here in 1967. Dr. Leonardo Leonidas told the council Monday evening that fluoride is more accessible in the average American diet than ever before, putting people at risk for ingesting too much. While he promotes dispensing fluoride as a supplement to children who don’t get enough, Leonidas feels it is more appropriate to prescribe it on a case by case basis, rather than dosing entire populations through the public water supply.

Leonidas’ proposal — drawn on studies from India and China, a recent report from a respected American research institute and his own observations — disappoints and angers area dentists and public health advocates, who fear his request will stir up unfounded controversy over a widely accepted practice with proven benefits. But concern about fluoride is nothing new, and despite its apparently benign presence in the tap water we drink and cook with, there are plenty of people who think we’d be better off without it.

What is fluoride?

Fluoride is a naturally occurring mineral found in many drinking water sources, including private wells. At low levels, it’s considered a beneficial “trace element,” strengthening tooth enamel and staving off decay. Too much fluoride, however, is associated with a host of serious disorders, including tooth and bone disease, organ failure, brain damage and cancer.

In a few places across the country, the level of natural fluoride is dangerously high — for this reason the federal Environmental Protection Agency monitors it as a contaminant and currently caps the acceptable level in drinking water at 4 parts per million. But most water has very little or no natural fluoride. About two-thirds of the public water systems in the United States currently add fluoride in an effort to improve the health of consumers’ teeth. Systems are required to monitor the additive closely to maintain the therapeutic range between 1ppm and 2ppm.

A March 2006 report from the National Research Council recommends dropping the acceptable maximum level of naturally occurring fluoride in drinking water from 4ppm to an unspecified lower amount, narrowing the gap between what the EPA considers toxic and what the public health community says is therapeutic. The American Dental Association earlier this month warned parents that mixing infant formula or baby foods with fluoridated water may actually damage emerging teeth.

Recent studies indicate that fluoride is present in many processed foods and soft drinks as well as in many brands of toothpaste and mouthwash, sources that were unavailable when fluoridation first gained acceptance. The widespread use of these modern products, especially by children, increases the likelihood that people, especially children, will consume more fluoride than is good for them.

Still, public health officials and professional groups maintain that controlled fluoridation of drinking water is a safe and effective practice with profound benefits for the general public. The federal Centers for Disease Control and Prevention, the U.S. Surgeon General, the American Dental Association, the American Academy of Pediatricians and many other groups support fluoridation as the single most cost-effective public health intervention ever.

Waterville pediatrician Michael Hofmann says the endorsement of these respected medical groups is proof enough for him and should be enough to guide public policy. He also has witnessed firsthand the protective power of fluoridation. With 40 years of practice in communities with and without fluoridation, he said young patients who drink water fortified with fluoride have dramatically healthier teeth.

“It is my professional belief that fluoride in drinking water prevents cavities and is safe,” he said in a recent interview. As an expert who has been asked to speak in communities weighing the fluoride option, he said responsible citizens with medical credentials should be promoting fluoridation, not trying to derail it.

In Bangor, pediatric dentist and public health advocate Jonathan Shenkin said contemporary research confirms the safety and efficacy of public water fluoridation. Concerns about overexposure are best addressed by educating parents to avoid fluoride-containing toothpaste and mouthwashes for their very young children, he said.

Shenkin said many communities that stop their fluoridation programs restart them after seeing deterioration in their children’s oral health. While there’s nothing wrong with prescribing fluoride to specific individuals, he said, the people who typically need it most — the poor, the uneducated — are the least likely to purchase the supplements or use them appropriately. With fluoride in the water supply, he said, “People don’t have to do anything” to get the benefit of fluoride.

But that passive consumption is just what bothers Michael Connet of the international Fluoride Action Network. The nonprofit group seeks to educate consumers about the dangers of exposure to fluoride in water supplies, foods, pesticides and other sources. Connet said in a recent phone interview from his home in Vermont that most people don’t have any idea whether their water contains added fluoride and don’t understand the risk of overexposure.

“The fact that it’s been going on so long doesn’t mean it’s OK,” he said.

Connet likened fluoridation to the practice of adding lead to gasoline, which started in the 1930s and was only recently discontinued when it was found to have significant health and environmental impacts. Another example is hormone replacement therapy for postmenopausal women, he said, an accepted medical treatment for decades, recently determined through modern research to put women at high risk for heart disease and other problems.

Fluoride in Maine

But the decision to fluoridate, or to stop fluoridating, is not made by medical professionals, public health officials, consumer groups, the government or public water utilities. It’s made by local voters, one water system at a time. And many communities have rejected fluoridation — some repeatedly. Many turn it down because consumers are unconvinced of the dental benefit or safety, and some have a philosophical objection to “medicating” the water supply. Others, especially in smaller utilities, consider cost as well — fluoride treatment adds significantly to the complication and cost of running a public water system, and that cost gets passed on to consumers.

Of Maine’s roughly 150 regulated public water utilities, about half currently add fluoride. The water system in Norway was the first, beginning in 1952. Many communities, including Bangor, came on board in the 1960s and ’70s. The 1980s saw almost no new converts. Fluoridation picked up again in the ’90s. Portland and Augusta waited until 1997. The most recent Maine utility to incorporate fluoride is York, which started in 2004.

In Bangor, the process has been running smoothly since it started in 1967, according to Kathy Moriarty, assistant general manager and water quality manager at the Bangor Water District. Nowadays, she said, fluoride in liquid form is delivered by truck to the water treatment plant at Flood’s Pond in Otis. It’s double-checked to be sure it’s the right stuff, then stored in a 3,000-gallon fiberglass tank surrounded by a concrete barrier to contain any spills. It’s considered a hazardous material and has special regulations surrounding its handling. Every night at midnight an operator tops off a 50-gallon “day tank.” Over the next 24 hours, the fluoride is fed at a steady rate into the 18-inch pipe that carries the treated water 15 miles cross-country to Bangor.

The natural fluoride in Flood’s Pond tests at 0.2ppm; the treated water is tested twice a day in the district’s certified laboratory to ensure the fluoride level is on target at 1.2ppm. Moriarty said the amount is almost always correct, and has never gone above the 2ppm industry standard.

She said public concern about fluoride ebbs and flows, occasionally spiking among consumers, environmentalists and activists.

“People have differing views,” she said, adding that in her 15 years at the district there has never been any public objection raised to the fluoridation process. “I have never gotten one phone call, except from parents new to the area who want to know whether their children need fluoride drops,” she said.

The district takes no position on the value of fluoridation, Moriarty stressed. “We add the fluoride because it’s what the citizens decided to do,” she said.

The Bangor Water District, which also provides water to customers in Clifton, Eddington, Hermon, Orrington, Veazie and Hampden, spends about $18,000 a year on fluoridation.

Drinking water quality in Maine is monitored and regulated by the state Department of Health and Human Services. The department’s Oral Health Program promotes fluoridation as a way to extend dental protection to Maine’s dentally underserved residents. But program director Judy Feinstein said the state never pressures communities to undertake fluoridation; under state law, the initiative must come from the people, she said.

Feinstein said legislative records from the 1950s reveal lawmakers’ squeamishness on the then-new idea of fluoridation.

“It is very clear that the Legislature didn’t want to touch this one,” she said. “It had to be a local decision; it had to go to the people.”

Maine communities revisit fluoridation

In Somerset County border towns, the water district serves about 1,500 people in Jackman and nearby Moose River. On Nov. 7, voters there turned down a measure that would have discontinued the utility’s 35-year-old fluoridation program.

“Our board thought the new generation should have a chance to vote on it,” said district administrator Sandra Feeney. The district organized a public forum with speakers representing both sides of the debate, including Feinstein from the Maine CDC and Connet from the Fluoride Action Network. Other than board members, employees and others directly connected to the town or the water district, only three residents showed up. Feeney said many voters simply didn’t understand the issue and voted to keep the status quo. She expects to see the question resurface in two years, the earliest it legally can.

Voters in Lincoln and Howland, where the Lincoln Water District provides the public drinking water, also weighed in on fluoride this year. According to superintendent David Emery, the water in Lincoln is so good that it’s barely even chlorinated; it’s never had fluoride added. More than 70 percent of voters supported maintaining their water’s purity, handily turning down the fluoridation proposal, which had been brought by a local health care group.

Emery said a yes vote on fluoride would have cost ratepayers about $128,000 in startup costs.

Lincoln town manager Glen Aho actively lobbied against the fluoridation measure. In addition to being unconvinced of its dental benefits, Aho said that as much as 40 percent of the public water is used at the Lincoln Paper and Tissue mill.

“That tissue paper is no better and no worse with or without fluoride,” he said.

At the Mount Desert Water District in Northeast Harbor, manager Paul Slack said there is interest in discontinuing the fluoride program. In Ellsworth, which also fluoridates, city manager Stephen Gunty said the issue recently has been discussed, but only informally.

Meanwhile, back in Bangor

City manager Ed Barrett said Thursday that the city will look to the Bangor Water District to lead any public discussion of the fluoridation program. A videotape of Dr. Leonidas’ presentation to the city council has been sent to district officials, he said.

Leonidas has accepted an invitation to the next meeting of the water district board, to start at 3:45 p.m. Tuesday, Nov. 21, at 614 State St. Moriarty said the district is prepared to respond to questions about the fluoridation program. Meetings are open to the public.

For a list of Maine communities with fluoridated water supplies, visit the BDN Web site: www.bangordailynews.com