Earlier this month, after more than six hours of mostly negative testimony, the Portland City Council voted unanimously to add fluoride to the city’s water supply starting in early 2014.

Until then, Portland was the largest U.S. city to decline community water fluoridation. The city was long opposed to it because of liberal ideologies that reject adding chemicals to the public water supply.

Before Portland, the largest city without fluoride in its water was San Jose. The city’s water board in late 2011 unanimously voted to add the mineral to its supply, but the city has yet to agree on when the measure will be implemented, according to American Dental Association spokeswoman Lydia Hall.

The Wichita City Council in Kansas last month decided to allow the public to vote on a public water fluoridation measure that will be included in the city’s Nov. 6 general election ballot.

And New Jersey’s state Legislature is considering a bill that would require all public water supplies to be fluoridated. According to the Centers for Disease Control and Prevention (CDC), just 13.5 percent of the state’s population had access to publicly fluoridated water in 2010.

That makes New Jersey second to last in the country when it comes to statewide fluoridation rates.

Hawaii is last, with just under 11 percent of the population receiving fluoridated water. (Only the island’s military installments provide fluoridated water.)

Why Community Water Fluoridation?

Fluoride is commonly added to public water supplies to reduce tooth decay, also known as caries — a problem that disproportionately affects children from lower-income families, according to the CDC. The CDC estimates that roughly half of all children and two-thirds of adolescents aged 12 to 19 from lower-income families have suffered from tooth decay.

In fact, the CDC has dubbed community water fluoridation as one of the country’s “Ten Great Public Health Achievements” of the 20th century.

Grand Rapids, Mich. in 1945 became the first city in the world to implement community water fluoridation. The practice entails adding a small amount of the mineral to the public water supply so that the fluoride concentration reaches 0.7 parts per million, per the U.S. Department of Health and Human Services’ recommendation. (Most drinking water sources already contain a small amount of naturally occurring fluoride.)

Studies, including those conducted at Grand Rapids, show that water fluoridation decreases tooth decay by about 25 percent over an individual’s lifetime, according to the CDC.

Proponents also say that community water fluoridation is cost-saving. The CDC states that every dollar invested in such a system yields roughly $38 savings in dental treatment costs. According to the American Dental Association, which has endorsed community water fluoridation since 1950, an individual can have access to a lifetime of fluoridated water for less than the cost of a dental filling.

The ADA estimates that the cost of fluoridating public water ranges from 50 cents to $3 per person per year.

But the custom has its fair share of critics, not least in Hawaii. Indeed, water fluoridation has long been the subject of an emotionally charged debate — much like that over genetically modified organisms, or GMOs. The sides have stuck to their guns as interest in the issue has waxed and waned both locally and across the country.

None of Hawaii’s four counties fluoridate its water, though Honolulu is the only county to explicitly prohibit fluoridation. The state Department of Health in the past promoted fluoridating the water supplies in Lanai and Molokai, but its initiatives were met with fierce opposition.

Critics: Fluoridation Unhealthy & Unwarranted

Critics say public water fluoridation equates to government-forced, mass medication. Some assert that fluoride lowers I.Q and causes cancer.

Fluoridated water can also have severe repercussions for people who suffer from Multiple Chemical Sensitivity (MCS) syndrome and impaired immune systems, according to Bobby McClintock, founder of the Respiratory and Environmental Disabilities Association of Hawaii.

“For those of us disabled with MCS, water fluoridation can harm us irreparably,” he said. “I cannot freely travel within my own country because of this toxin. I cannot shower in it, eat anything washed or cooked in it, never mind drink it. So, since I have become disabled I cannot visit family and friends in fluoridated communities.”

McClintock is well aware of positions taken by national pro-fluoride organizations such as the ADA, which states that “Studies conducted throughout the past 65 years have consistently shown that fluoridation of community water supplies is safe and effective in preventing dental decay in both children and adults.”

The organization’s fluoridation policy is based on “the overwhelming weight of peer-reviewed, credible scientific evidence,” according to its website.

But McClintock doesn’t buy it. “They rely on a tired-song saying no one has been harmed by it all these years and anyone who doesn’t agree is a fanatic,” he said.

He cited fluoride’s Material Safety Data Sheet, which outlines warnings associated with the ingredient.

The Fluoride Action Network has compiled a list of communities that have rejected fluoridation since 1990.

In Hawaii, environmental groups have also testified against the chemical on the grounds that it pollutes the water.

Others assert that public health officials can target tooth decay, or caries, through other mechanisms, such as subsidizing dental care and encouraging proper dental care and alternative forms of fluoride treatment.

Hesh Goldstein, who moderates the local “Health Talk” radio program and testified in support of Honolulu’s fluoride ban back in 2004, pointed to a 2001 CDC report which indicated that fluoride is most effective in preventing tooth decay when applied topically.

“Nowhere does it say you have to drink it,” he said. “Fluoridation is merely a way for people that had to dispose of it as a toxic waste product to make money off of it. It was one of the best, most deceptive PR campaigns ever. Right up there with the whole GMO issue.”

Advocates: Fluoride’s Benefits Outweigh Its Costs

But proponents maintain that there is little evidence to substantiate critics’ claims.

“People are rightfully suspicious of government attempts to ‘make them better,’” said Michael Rethman, a local dentist and former chairman of the ADA. “But this has been going on for such a long time and demonstrated its usefulness, and I consider it an exception. When the evidence is just overwhelming, there comes a time when you have to step back from the skepticism…When it comes to community water fluoridation, the benefits are clear.”

Yolanda Wu, a pediatrician at Kapiolani Medical Center, agreed that fluoride’s pros outweigh its cons.

“It helps strengthen teeth, even while their teeth are developing,” she said. According to Wu, the only known side effect of water fluoridation is fluorosis, or mild teeth discoloration.

Wu, who is also member of the American Academy of Pediatrics, emphasized that dental decay is an illness that can lead to significant health problems. She cited children who had been admitted to the hospital due to brain abscesses caused by cavities. Dental decay, if left untreated, can allow infectious bacteria to enter the brain, she said, noting that the problem tends to be more prevalent among children from lower-income families.

“A lot of the people who do have bad cases of caries don’t have access to dental health,” said said.

And Wu added that while pediatricians prescribe daily-dosage fluoride pills, “there’s always the problem with compliance.”

Rethman pointed to statistics from Healthy Smiles Hawaii, a local dental health program. The rate of tooth decay among children living in Hawaii is two times as high as that among children on the mainland, according to the program’s data.

Where as mainland children have an average of two decayed teeth, Hawaii children ages five through nine have an average of four decayed teeth.

And in Hawaii tooth decay — namely baby bottle tooth decay — is statistically more prevalent among certain children. While roughly 16 percent of all Hawaii 5-year-olds in 2003 suffered from baby bottle tooth decay, the condition affected their Native Hawaiian and Filipino counterparts at rates of 21 percent and 32 percent, respectively. On Molokai, 33 percent of children were affected.

Less than 19 percent of local 6-year-olds bear cavity-free permanent teeth, compared to more than 94 percent of their mainland counterparts, according to Healthy Smiles Hawaii statistics.

“Cavities are a problem here,” said Rethman. “They interfere with kids’ ability to eat and affect their appearance and comfort. All those things would suggest that having fluoridated water would be useful.”

Yet, Hawaii legislation has consistently favored those who oppose water fluoridation.

Rethman speculated that the reason for that discrepancy could in large part be Hawaii’s isolation. He also suggested that Hawaii is home to a large percentage of non-native English speakers who “rely on experts in their communities to advise them.”

“Sometimes I think the experts are easily manipulated,” he said.

But Councilman Garcia doesn’t think the local community will revisit the debate anytime soon.

“There needs to be some kind of groundswell, and I haven’t seen it yet,” he said.

Rethman agreed: “There’s always a lot of inertia with the status quo.”