Machias voters will decide next week whether to continue adding fluoride to the town water supply.

“[Shall] fluoride be added to the public water supply for the intended purpose of reducing tooth decay?” reads Article 55 for the 2016 Machias town meeting, set for 7 p.m. Wednesday, June 15, in the Machias High School gymnasium.

The issue came up in January when resident Vince Roberts complained that adding fluoride to the water is dangerous.

“[Fluoride] is stronger than chlorine,” Roberts said at the Jan. 13 selectmen’s meeting. “It makes chlorine look like candy. People just don’t realize it.”

In January, Roberts handed out copies of “Fluoride Facts” from About.com and underlined a passage that says, “The presence of sodium fluoride in drinking water at the level of 2 ppm [parts per million] may cause mottled enamel in teeth, skeletal fluorisis and may be associated with cancer and other diseases.”

According to the Maine Center for Disease Control and Prevention’s Division of Environmental Health website, the level of fluoride used in water in Maine is 0.7 ppm.

Roberts did not attend the June 8 selectmen’s meeting but did ask Town Manager Christina Therrien to give a handout to the selectmen. The handout, which cited the Fluoride Action Network as its source, says fluoride is the only chemical added to the water for the purpose of medical treatment. Because it is in the water, residents do not get the chance to consent to or opt out of this treatment.

The Fluoride Action Network website includes an Oct. 19, 1981, article that says about 60 students and faculty at Jonesboro Elementary School were poisoned that month after a valve malfunctioned and released too much fluoride into the system. Most experienced abdominal pains, nausea and vomiting. The victims were treated at Down East Community Hospital and “later released with no further ill effects,” according to the article.

Numerous groups, including the American Dental Association, the American Medical Association and the World Health Organization, support adding fluoride to the water.

The American Dental Association has called community water fluoridation “one of 10 great public health achievements of the 20th century.” In a video posted to YouTube in December 2015, U.S. Surgeon General Vivek Murthy credited water fluoridation with helping reduce the prevalence and severity of tooth decay.

If Machias voters decide to stop fluoridating the water, the town would become one of only four municipalities in Maine to discontinue using the additive, which is designed to improve dental health.

Carlton Gardner, compliance enforcement team manager for the Maine Drinking Water Program, said in January that he knows of only three Maine municipalities whose residents have voted to stop fluoridating water. The communities of Jackman, Seal Harbor and Northeast Harbor all voted to discontinue adding fluoride in 2007, he said.

A total of 65 community water systems fluoridate the drinking water provided to 133 municipalities in Maine, according to the state CDC’s Division of Environmental Health website. Another three municipalities — Friendship, Waldoboro and Warren — have naturally occurring fluoride.

The first municipality to add fluoride was Norway in 1952, followed by Baileyville and Brunswick, both in 1955. Machias added fluoride to its water starting in 1966, according to the Maine CDC.

The selectmen in Machias have not taken a position on fluoridation referendum questions.

“I think it’s a decision that the taxpayers should make,” Selectman F. James Whalen said in January. “It’s not a decision for us to make.”