Despite widespread belief among US health officials in fluoride’s safety and effectiveness, dozens of activists north of Boston are pushing for communities to eliminate it from water supplies, saying the fluoridation process medicates residents without their consent.

Two local organizations — Health Roundhouse , a group that has focused its activism in Newburyport, and the Cape Ann Fluoride Action Network , made up of fluoride opponents in Gloucester and Rockport — have petitioned local governments to allow residents to vote on the issue.

Twenty to 25 people are actively involved in Health Roundhouse and about a dozen in the Cape Ann Fluoride Action Network, group members say.

Rockport residents will vote this spring on whether to stop adding fluoride to their drinking water. And in Gloucester, a committee is in the process of drafting one or two possible ballot questions; if a majority of the City Council votes in favor of the questions, residents will vote on the issue in November.

Similarly, in Newburyport, petition language is being verified by the city’s attorneys, and the council will then vote on whether to approve the question before it goes to a citywide vote.

In Topsfield, the town moderator is expected to appoint a five-member committee to study the issue. The committee will return with a recommendation to the town at the spring Town Meeting.

Tracey Chiancola, 53, of Gloucester, runs the Cape Ann Fluoride Action network along with her sister, who is from Rockport. Chiancola described the antifluoride movement as a grass-roots effort, and said she and her sister have connected with other activists via social media. They have also attended meetings in other communities to share information and show support.

In the past few months, Chiancola said, they have handed out pamphlets, showed a documentary on the dangers of fluoride, written letters that have been published in the Gloucester Daily Times, and hosted a talk with a representative from the Fluoride Action Network , an organization that says it seeks to educate people about the toxicity of fluoride.

“It’s mass medication, and it takes away the freedom of choice,” Chiancola said of the fluoridation process.

Gloucester City Councilor Greg Verga said he favors taking fluoride out of the water. He describes himself as a tooth-brushing fanatic, but said that fluoride should be a personal choice, like taking a flu shot, and not mandated by the government.

He would like to see the $9,000 or so the city spends on fluoridation each year redirected to fund education initiatives on the importance of fluoride, or to the distribution of fluoride tablets.

“We should be targeting the people who need it,” Verga said.

According to the state’s Department of Public Health, communities north of Boston that do not fluoridate water supplies include Amesbury, Chelmsford, Georgetown, Merrimac, Methuen, Rowley, and Salisbury.

Communities in this area have a lengthy history of opposing water fluoridation. The Globe reported in 2002 that Methuen residents voted against adding fluoride to their supply. In November 2011, Amesbury residents voted to stop adding fluoride into the municipal drinking water supply. And in May 2000, Rowley voters rejected a proposal to add fluoride to the town’s drinking water, according to Town Administrator Deborah M. Eagan. Since that time, the issue has not resurfaced at Town Meeting or as a ballot question, she said.

Ned Robinson-Lynch, director of the Division of Health Access at the Massachusetts Department of Public Health, said his department strongly supports community water fluoridation, and monitors the levels of fluoride in 135 towns and cities in Massachusetts.

He said it has been proven by solid research to reduce cavities.

“For those who don’t get to the dentist or who don’t get the recommended frequency [of fluoride], it’s the single most preventative measure,” he said.

Opponents say fluoride can cause a host of health problems, such as bone disease. According to the Fluoride Action Network, excessive fluoride exposure has been linked to many ailments, including arthritis, glucose intolerance, gastrointestinal distress, thyroid disease, and possibly cardiovascular disease and some cancers.

At the Newburyport City Council meeting Jan. 12, Christopher Martel, a financial adviser from Amesbury, said he advocated for residents to vote to remove fluoride from the town’s water supply in 2011, and he thinks more communities will move to rid water of fluoride.

“It is unethical and immoral to force people to ingest something against their will,” said Martel, 48.

Andrew Teichner, the founder of Health Roundhouse, said he had spent about $2,000 on books to study fluoride as a toxin. Teichner said in an interview that people are oversaturated with fluoride; they drink, cook with, and bathe in fluoridated water, and then brush their teeth with toothpaste that has added fluoride.

“We’re medicating people without their permission,” he said. “People should have informed consent.”

But Dr. Sam A. Merabi, a dentist in Newburyport and faculty member at Harvard School of Dental Medicine, said there is no proof that fluoride causes medical problems, and a person cannot consume too much fluoride by drinking municipal water because it is highly diluted.

Merabi, who was the only person who spoke out against removing fluoride from the water at a recent Newburyport City Council meeting, said in an interview that the antifluoride initiative is a “fear-mongering political movement.” These activists are not looking at the large body of research that shows the public health benefits of fluoride, he said. Instead, they are identifying outliers and twisting them.

“A lot of this antifluoride information is really junk, and it’s presented as credible,” he said.

Dr. Merabi also said he has worked in communities where fluoride was not added to the water, and he found that children were much more susceptible to cavities as their teeth were still developing.

Robinson-Lynch, of the Department of Public Health, said he understands the issue is controversial and concerning to people, but he wants residents to educate themselves when voting on whether to remove fluoride from the water.

“My hope is that with a review of science and evidence, people will realize that it’s safe and a successful measure to improve oral health for everybody,” he said.