In Dutchess County, Poughkeepsie is the only one of 725 public water systems that adds fluoride to drinking water.

That could change, though. Commissioner of Health Dr. Michael Caldwell has made it a priority this year to inform public water providers about the benefits of fluoride in cavity prevention, in hopes that more choose to do so.

“To me, it’s equivalent to the success of immunizations,” Caldwell said. “There’s nothing else we’ve been able to do on a community-wide level to improve dental health as fluoride has done.”

In advocating for increased fluoridation, Caldwell is advancing an initiative the Centers for Disease Control calls one of the nation’s top 10 public health achievements of the last century.

He’s also wading into a controversy. A network of opposition groups argues that increased access to other forms of fluoride, as well as a suspected link to bone cancer, should make fluoridated drinking water a thing of the past.

Fluoridation has been controversial from the start. At the height of the Cold War, it was branded by some as a Communist plot. Even today, it continues to divide communities across the country, as court cases and referenda have pitted opponents of fluoridation against those who want it added to more water supplies.

The Poughkeepsie Joint Water Board recently suspended fluoridation and considered discontinuing the practice. It decided to keep it in the water supply of roughly 80,000 people in the Poughkeepsie and Wappingers Falls area, based on the recommendations of public health agencies.

At least one board member vowed to continue arguing for its removal.

“I’m 100 percent against it,” said Frank Mora, the former chairman of the Poughkeepsie Common Council who has served on the water board for six years. “That stuff is one of the most dangerous chemicals around. You put some on your hand or skin, and it will go down through your bone. You’re telling me this is good for us?”

On the pro side are public health heavyweights — the Centers for Disease Control and Prevention, the American Dental Association and the state Department of Health, among them. The benefit, particularly for low-income children that are less likely to get fluoride supplements from their dentists or pediatricians, is a reduction in cavities and tooth decay.

The CDC estimates 1 milligram per liter of fluoride — as is normally added to the water in Poughkeepsie — staves off 18 to 40 percent of tooth decay problems in children.

Sources plentiful

It’s important for parents to understand all the sources of fluoride today — from toothpaste to fortified bottled water and even soft drinks made from fluoridated water — to avoid giving their children too much, said Dr. Clifford Hames, the dental director for Hudson River HealthCare Inc. But fluoridation of drinking water remains critical for improving the dental health of the low-income uninsured population Hudson River HealthCare Inc. serves.

“Fluoridated water is probably the single most effective public measure that’s been implemented to prevent tooth decay,” Hames said. “When it’s properly monitored, it’s very effective.”

The benefit is strictly for children whose teeth have yet to fully emerge in the mouth, Hames said. Adult teeth — particularly those of the elderly — can benefit from fluoride, but only topical formulas such as rinses, toothpastes or foams are effective.

Opponents see the endorsement of health agencies as the product of slow-to-change bureaucracies that have yet to deal with the latest evidence. They see too little benefit, considering the other available sources of fluoride and the perceived risk of bone cancer from ingesting fluoride.

In September, 11 unions representing more than 7,000 workers at the Environmental Protection Agency called for a national moratorium on water fluoridation in light of allegations a Harvard University dentistry professor downplayed research showing an increased risk of a rare bone cancer, osteosarcoma, for boys who drink fluoridated tap water.

The EPA is waiting on the National Academy of Sciences, which is reviewing all evidence related to fluoride’s potential toxicity. That 3-year-old analysis is expected as early as next month.

The history of fluoridation in public water is tied closely to the Hudson Valley.

Added since 1945

Fluoride has been added to water since 1945, when Newburgh and Kingston were among the first eight cities to participate in studies that showed fluoridation reduced tooth decay. Poughkeepsie’s water has been fluoridated nearly as long.

The Hudson Valley also became the epicenter of the first concern about the potential for fluoride to cause bone problems. A National Academy of Sciences report in 1977 raised concerns about bone structure problems that were twice as prevalent among Newburgh residents as in Kingston, according to the Environmental Working Group.

Subsequent studies have come up with conflicting results, with some showing a correlation between bone cancer in boys who drink fluoridated water at certain ages, and others showing no correlation.

One thing is certain: Handling the chemical in its raw form can be hazardous to workers.

Hydrofluorosilic acid, the colorless liquid fluoride compound added to water, is toxic and caustic.

Industry standards recommend it be housed in a separate building with its own ventilation system to prevent exposure to workers.

It was a concern for water plant personnel that inspired the Poughkeepsie Joint Water Board to consider ending fluoridation, since its facility doesn’t meet the latest recommendations.

Poughkeepsies’ Water Treatment Facility has suspended fluoridation until it installs a new piping system and a 2,500-gallon tank outside the plant, to meet those recommendations. The work could take six months.

“It’s a very strong acid, and fluoride has a tendency to go to the bones,” plant Administrator Randy Alstadt said, referring to fluoride’s tendency to accumulate in bones. “If there is a spill, it’s going to be very hazardous to clean up.”

The cost of adding fluoride to the water supply is not excessive, Alstadt said. It costs about $40 a day — less than one percent of the $7,600 daily cost of running the plant.

Fluoride is one of several substances added to the water supply, and each poses hazards to workers in its raw form, Alstadt said.

Fluoride is the only substance added to the water as a health supplement. Other chemicals are added to kill pathogens, remove sediment, adjust the pH and prevent pipe deterioration. The water is also filtered through sand and charcoal, and treated with ultraviolet light.

Poughkeepsie has long been on the forefront of water treatment, and the water is safe to drink by all state and national standards. Unlike bottled water or private wells, public water supplies must be tested routinely to ensure they don’t exceed strict limits for a variety of contaminants.

Poughkeepsie Mayor Nancy Cozean, a member of the water board, is among those who believe fluoride is a good addition to the local water supply, especially for Poughkeepsie’s poor, who may not get regular dental and pediatric care.

“Tooth decay can not only lead to illnesses, it can, if you have an abscess, become debilitating,” Cozean said. “It’s important to provide preventative measures.”