Chances are that if you were a dentist in the early part of the 20th century, the majority of your work involved pulling teeth or fitting folks for dentures, with roughly half of all Americans having dentures by the age of 55. By the year 2000, about nine percent of adults age 45-54 had lost all their teeth, down from 20 percent in 1960, according to the national Centers for Disease Control (CDC).
Today, the largest factor in reducing tooth decay is the use of fluoride, both in toothpaste, varnishes and in the water we drink. First introduced in 1945 in Grand Rapids, today more than 70 percent of the nation's public drinking water is now fluoridated, leading the CDC to name fluoridation of water one of the greatest achievements in public health in the 20th century.
“Water fluoridation is the best method for delivering fluoride to all members of the community, regardless of age, education, income level or access to routine dental care,” according to the American Dental Association. “Fluoride's effectiveness in preventing tooth decay extends throughout one's life, resulting in fewer – and less severe – cavities. In fact, each generation born over the past 70 years has enjoyed better dental health than the one before it. That's the very essence of the American promise.”
Despite the health benefits of fluoridation, there has been a vocal group of skeptics who believe fluoridation may be more harmful than good.
Hardy Limeback, a retired dentist and former head of Preventative Dentistry at the University of Toronto, was one of 12 scientists in North America chosen to serve the National Academy of Science's committee that produced the “Fluoride in Water” report in 2006. While the report supported the use of fluoride in water, Limeback said he has since changed his mind.
“I was mistaken,” he said. “It became clear to me that even at low chronic daily intakes of fluoride, such as those provided by fluoridation, susceptible and vulnerable groups of the population can experience ill health effects.”
Limeback said research shows water fluoridation accumulates in bones in adults to high levels at which bone is at risk of fracture. Further, he said significant and severe dental fluorosis – a condition marked by stained and pitted teeth – is a potential for children, especially when fed infant formula made with fluoridated water.
Other claims from water fluoridation opponents range from those based on solid scientific research to political conspiracies that fluoridation was introduced as part of a Communist plot to control the United States population. Such wild conspiracies were even included in the 1964 black comedy, Dr. Strangelove:
“Mandrake, have you ever seen a commie drink a glass of water. … Do you realize that fluoridation is the most monstrously conceived and most dangerous communist plot we have ever had to face,” character Brig. Gen. Jack Ripper said in the film.
In 2015, the U.S. Department of Health and Human Services (HHS) lowered the recommended optimal level of fluoride in drinking water to prevent tooth decay from 1.2 milligrams per liter to .7 milligrams per liter, or .7 parts per million (ppm).
The change, the first since it was issued by the department in 1962, was recommended because people now have access to more sources of fluoride, such as toothpastes and mouth rinses, than they did when water fluoridation was first introduced.
The lower standard has provided more fuel to the fluoride debate, which has been discussed in one form or another since it was first added to public drinking water systems.
Take, for instance, truther Alex Jones with the website Info Wars who has made outlandish claims about water fluoridation: “What do you think water is? It's a gay bomb, baby,” he has said in regard to fluoridation.
While such beliefs are often disregarded as fringe conspiracies, they also provide a disservice to legitimate research regarding fluoride and its potential health effects.
In the United States, the most common issue associated with excessive fluoride exposure is a dental condition known as fluorosis. The condition, which can cause small white spots in mild cases, and pitting and dark stains in more rare cases, is caused by excessive exposure to fluoride as a child. Such levels are related to naturally occurring fluoride in drinking water sources, and not those related to water fluoridation.
As excessive amounts of fluoride does indeed have detrimental health impacts – the U.S. Environmental Protection Agency (EPA) sets a maximum contaminant level of fluoride in drinking water at four ppm. However, the department has said that level is being reviewed and may be lowered in the future.
The EPA also maintains a “non-enforceable” secondary standard for fluoride of two ppm, which is recommended to protect against moderate and excessive fluorosis. Levels above four ppm may lead to crippling skeletal fluorosis, a condition that is characterized by pain and tenderness of major joints.
“In some countries, it has been considered a risk to public drinking water, but in most of the United States there hasn't been much concern,” said University of California San Francisco Professor Howard Pollick, who chairs the California Fluoridation Advisory council and is a national expert on the issue. “About half of the population – it varies from place to place – will drink and cook with (fluoridated) tap water and make beverages with tap water. And it's not just drinking water, it's also cooking and having food processed that conveys a benefit. Small concentrations of fluoride really do make a difference.
“In terms of what we know and what's credible and what isn't – I love working with the internet, but the internet is replete with information, or disinformation, on fluoridation, vaccinations and other issues. And we see that people are susceptible to information they get from friends and the internet. It's a constant struggle.”
One of the largest and most outspoken anti-fluoridation groups on the internet is the Binghamton, New York-based Fluoride Action Network (FAN). The group's website has a wealth of information, including both generally accepted studies, as well as more outlandish claims, such as the premise that fluoridated water may have exacerbated the lead water crisis in Flint.
For instance, a 2016 article on the site stated that fluoride can be corrosive, which in itself is credible. However, the article failed to distinguish water with fluoride at one ppm or less and extremely high levels of fluoride that may be used in an industrial setting. Omitting this important distinction, the article said fluoridation programs are “adding fuel to the fire of America's lead crisis, in Flint and beyond” – never mind the fact that Flint's water had been fluoridated for decades prior to the lead crisis that was caused by the city's failure to provide an anti-corrosive measure in its water after switching from the Detroit water system as a provider.
The FAN story also referred to high lead found in children's blood in six other Michigan cities, which coincidentally fluoridate their water. The article failed to mention that most, if not all, of those levels reported by the MHHS have been linked to lead paint.
Still, in speaking with FAN Executive Director Paul Connett, he said his concerns are based on research that had been accepted by reputable science journals and experts in the field.
“The most immediate concern is for the impact of fluoride on the thyroid gland, which in a pregnant mother could impact a baby's IQ,” he said. “That's a big issue that should have been understood before fluoridation started.”
Connett said the issue may or may not be the cause of lowering IQs cited in more than 50 studies that found lowered IQs in villages with high levels of fluoride. He also cited a National Institutes of Health (NIH) study released in 2017 that found a strong association of fluoride exposure as measured in the urine of pregnant women.
“They measured those levels and IQ, and they found that as the fluoride level went up, that IQ went down, by about five to six IQ points,” he said. “On an individual level, that's not a huge amount, but what that means on the population level is incredibly important.”
To better understand the sources of fluoride and its relationship to human health, it's helpful to understand the origins of its use as a health benefit.
While the first city in the United States to implement fluoridation was Grand Rapids in 1945, the story of fluoridation began nearly 50 years earlier with a condition dubbed Colorado Brown Stain.
According to the National Institutes of Health, dentist Frederick McKay opened a practice about 1901 in Colorado Springs. It was there that McKay discovered natives of the city suffering from permanent brown stains on their teeth, the color of chocolate. After studying the condition with others, it was discovered the condition developed before permanent teeth had fully grown in, and that the affected teeth were oddly resistant to tooth decay. The condition was linked to the water supply, but it wasn't until 1931 when a researcher at ALCOA discovered the water had high levels of naturally occurring fluoride.
The findings eventually led researchers at the U.S. Public Health Services to look into fluoride and its impacts on tooth enamel. By the late 1930s, researchers with the National Institutes of Health learned that levels of up to one ppm in drinking water caused only mild fluorosis in a small percentage of people.
Building on the previous findings, researchers hypothesized that low levels of fluoride would help fight tooth decay. In 1944, the Grand Rapids City Commission was approached and approved testing the idea with the city's water supply, under the guidance of the Public Health Services, the Michigan Department of Health and other public health organizations.
Starting in 1945, fluoridation in Grand Rapids was to be tested for 15 years, with the city of Muskegon serving as the control city. The researchers monitored almost 30,000 schoolchildren during the study. After 11 years, it was found that cavity rates had dropped by more than 60 percent, marking a giant scientific breakthrough.
Pollick of University of California said the initial studies established the scientific evidence that an optimum concentration of fluoride to prevent cavities was about one ppm, while communities with more than two ppm would have a portion of the population with severe forms of dental fluorosis.
“It's a very fine line between one ppm and two ppm. A very small amount would be a big difference,” he said. “Usually, fluoride is found in rocks with phosphate and calcium or aluminum. It's not usually found by itself, so those rocks can be a source for that and other things.”
Going back to studies that correlate loss of IQ to fluoride exposure, proponents of fluoridation say those changes have been shown, but ring true in areas where fluoride levels are particularly high.
“Fluoride in the wrong amount can be toxic, but the concentration we are talking about to demonstrate toxicity is much higher,” said Carlos Gonzalez-Cabezas, a professor with the University of Michigan School of Dentistry who serves as director of the school's Global Initiatives in Oral and Craniofacial Health, and has specialized in research involving fluoride. “It's not surprising. It was used in rat poison decades ago, so it's not surprising that there's a need for continued research, as there could be populations that are more susceptible to it. But that's not just with fluoride, that's with anything, especially young ones.”
Gonzalez-Cabezas said there has been research from China and Mexico that have shown high concentrations of fluoride can reduce IQ, but it isn't comparable to levels in the United States.
“Most teens may have dental fluorosis, but there's no influence other than aesthetically, and you can only see it with a microscope. You can have more advanced levels with pits in the surface of the tooth, but that usually doesn't happen in the United States. Usually, that's in Mexico or other areas where they are drinking from wells with high concentrations of fluoride, maybe four ppm or eight ppm,” he said. “In China, they had levels so high from the consumption of fluoride that bones and joints will deform. We don't see that in the U.S. In those cases, they were drying vegetables with coal and it had a lot of fluoride, and that was only a percentage of the community. There were some that are more genetically susceptible than others.”
While the issue should continued to be studied, he said fluoridation in the United States still remains a great health benefit and should be continued.
“Fluoridation, personally, the importance today is most for people from people from lower socioeconomic groups, and the least for those from higher groups,” he said.
As results of the early studies from Grand Rapids were released in the late 1950s, other cities began following suit and fluoridating their water.
Cheryl Porter, chief operating officer of the Great Lakes Water Authority, formerly the Detroit Water and Sewerage Department (DWSD), said records show the city started fluoridating water in 1967, two years after a Michigan Supreme Court ruling on the issue. However, with the court case being decided in 1965, it's certain the issue was being discussed around dinner tables years prior.
“The 1965 Michigan Supreme Court ruling that the DWSD got started with the idea of adding fluoride to water. It was based on that legal precedent,” Porter said.
The case, Rogowski v City of Detroit, went before the Michigan Supreme Court in June of 1964 and was decided in January of 1965. At the time, about two-thirds of the state's 18 major cities were drinking water that contained supplemental fluoride, or roughly 1.25 million people.
The case stemmed from a lawsuit filed by Detroit resident Frank Rogowski and others against the city of Detroit, the city's board of water commissioners, and the Detroit Board of Health to stop the fluoridation of the city's water, as outlined in a city ordinance calling for the fluoridation of water. The city contended that under its policy, pursuant to its police power to promote public health, it could institute fluoridation into the city's water supply.
Arguments by the plaintiffs echo some of the same concerns about water fluoridation that are used today. Specifically, the plaintiffs claimed the city council had no authority to enact the ordinance; that the ordinance violates a statute forbidding the wholesale treatment of children by health officers other than to control epidemics of infectious disease without written consent of parents; that the ordinance isn't a reasonable exercise of the city's police power, there wasn't evidence to prove fluoridation can reduce tooth decay, and that fluoridation can harm the teeth of children; that the ordinance violates privacy rights of a person to choose what medications they will take; that the ordinance is an attempt to subject people to a scientific and medical experiment without their consent; that fluoridation is wasteful and uneconomical; and that the objective of reducing tooth decay could be done by other means, such as educational campaigns.
In deciding the case in favor of the city, the court cited a United States Supreme Court ruling involving a law in Massachusetts that made it a criminal offense for anyone over the age of 21 to refuse to comply with a city board of health requirement to be vaccinated for smallpox at public expense. In that case, the defendant was on trial for refusing the vaccination. In doing so, he claimed vaccinations were injurious and officials had no scientific evidence vaccinations actually preventing smallpox.
“There are manifold restraints to which every person is necessarily subject for the common good,” the US Supreme Court said in the previous case. “On any other basis, organized society could not exist with safety to its members. Society based on the rule that each one is a law unto himself would soon be confronted with disorder and anarchy. Real liberty for all could not exist under the operation of a principle which recognizes the right of each individual person to use his own, whether in respect of his person or his property, regardless of the injury that may be done to others.”
The state court also cited the federal court's ruling in that a consensus of the majority of the public and medical professionals is weighted more than opinions of some others: “It must be conceded that some laymen, both learned and unlearned, and some physicians of great skill and repute, do not believe that vaccination is a preventative of smallpox. The common belief, however, is that it has a decided tendency to prevent the spread of this fearful disease and to render it less dangerous to those who contract it. While not accepted by all, it is accepted by the mass of people, as well as by most members of the medical profession. … The possibility that the belief may be wrong, and that science may yet to show it to be wrong, is not conclusive; for the legislature has the right to pass laws which, according to the common belief of the people, are adapted to prevent the spread of contagious disease.”
The Michigan court then applied the same argument to fluoridation, as beneficial to prevent cavities.
“It is true that the smallpox disease involved in that case is infectious or contagious while dental cavities is not,” the Michigan court said. “Plaintiffs cite no cases to the effect that that element is essential to the power of the state to adopt or enforce regulations designed to protect or improve public health.”
Porter said while the DWSD has fielded concerns about fluoridation, she hasn't heard any since the formation of the Great Lakes Water Authority.
“We do have pushback on occasion,” she said. “I think the last one was concern about cancer. We probably had that conversation once over the past 10 years, while it was still under the DWSD.”
Porter said the water system conducts the fluoridation process using fluorosilicic acid. Other fluoridation methods utilize either sodium fluoride or sodium fluorosilicate. The process is done at the end of the water treatment process as a “post chemical.” She said lowering the amount from one ppm to .7 was an easy adjustment. However, any lower concentration would be difficult, and wouldn't likely offer a health benefit.
“It won't achieve its goal if we go below .5 ppm,” she said. “From an equipment standpoint, if it got lower, we would have to look at a capital investment to get much lower and be effective. With any mechanical equipment, there is an optimal operating level so we would have to shrink the system to go below .7 ppm.”
Porter said the system did lower the level from one ppm to .7 ppm in 2011, about four years prior to the recommendation. That decision was under the guidance of the DWSD Board of Water Commissioners.
According to 2012 records from the Michigan Department of Health and Human Services, about 13 communities tested in Michigan had fluoride levels above one ppm. All of those communities received their drinking water from ground water sources, but underwent a fluoridation process. Those communities included Brown City (1.7 ppm); Charlevoix Township (1.7 ppm); Garden (1.7 ppm); Millersburg (1.6 ppm); Onaway (1.6 ppm); Akron (1.6 ppm); Petoskey (1.56 ppm); Vassar (1.3 ppm); Richmond (1.2 ppm); Otisville (1.1 ppm); Lake City (1.1 ppm); Columbiaville (1.1 ppm); and Capac (1.1 ppm).
Community water systems at or below one ppm and above .7 ppm included: Caro (one ppm); Cheboygen (one ppm); Beecher Metropolitan District (one ppm); Boyne Falls (one ppm); Dryden (one ppm); Clifford, Armada, Memphis, Morenci, Stockbridge (.9 ppm); Marlette (.87 ppm); Pigeon (.81 ppm); Sebawing, Reading, Knorwood Knolls Subdivision in Oakland County, and Deckerville (.8 ppm); and Old Farm Colony in Oakland County (.73 ppm).
Oakland County communities that implement water fluoridation and tested at .7 ppm included: Royal Oak, Royal Oak Township, South Bloomfield Highlands, South Lyon, Rochester Hills, Pontiac, Rochester East, Pleasant Ridge, Orchard Lake Village, Novi, Oak Park, Orion Township, Milford, Huntington Woods, Hazel Park, Farmington, Farmington Hills, Ferndale, Commerce Township, Bingham Farms, Birmingham, Bloomfield Hills, Bloomfield Township, Berkley, Beverly Hills, West Bloomfield, Walled Lake, Wixom, Southfield, Sylvan Lake, Troy and the South Oakland County Water Authority.
Only two Oakland County residential areas that implement water fluoridation tested below the recommended .7 ppm amount, including Cass Lake Subdivision (.66 ppm) and Long Lake Village Subdivision (.6 ppm).
Oakland County communities with naturally occurring fluoride in their water and the amount tested included: Holly (.53 ppm); Oakland Hunt (.5 ppm); Orion Lakes (.5 ppm); South Highland Township Water Authority (.2 ppm).
Oakland County residential systems and communities that don't fluoridate their water and didn't show traces of fluoride in their groundwater included: Franklin Knolls Association; Deerwood Subdivision; Lyon Township; Chateau Cranberry Lake; Cedarbrook Estates; Clarkston Lakes MH Community; Country Estates; Bloomfield Orchard Villa; Oakland Township Southeast; Oak Hill Estates; Oxford; Oxford Township; Northeast Highland Township; Independence Township; Hidden Lake Estates; Highland Greens Estates; Highland Hills of Highland; Shashabaw Meadows; Rochester; Lake Villa Mobile Homes; Laguna Vista Subdivision; Springgrove Estates; Springs/Portsmouth Apartments; Waterford Township; Waters Edge; and White Lake Township.
Rochester Public Works Director Shannon Filerecki said the east side of the city is served by the Great Lakes Water Authority and receives fluoridated water. Residents on the west side of the city are served by the city's groundwater system, which has some naturally occurring fluoride, which tested at .43 ppm in 2017, the latest tests available.
“We have it naturally occurring, and we didn't see a need to supplement it,” she said.
Russ Williams, public works director for Waterford Township, said the community's well system has some naturally occurring fluoride already, but the amount fluctuates from well to well.
“We are showing an average of .44 ppm, and it samples from about .67 to .2,” he said. “It depends on how much we are pumping and how far into the aquifer. The maximum contaminant load is at four ppm, and the recommended value is .7, and we've never exceeded that. Higher fluoride amounts tend to come in the Appalachians. We've never had concerns to remove fluoride because it's been so low.”
While Williams said the township gets occasional inquiries about fluoride, he said there hasn't been hostile receptions because it's a naturally occurring matter. “In some places, there has been a public outcry against it. Our biggest concern is calcium and the hardness of the water. We definitely have some hard water here in Waterford, but that's much easier to handle on the residential level.”
Sandra Sutton, the state's water fluoridation coordinator and a dental hygienist with the Michigan Department of Health and Human Services, said few communities in the state have opted to stop fluoridation.
In 2014, Boyne City decided to stop fluoridating its water after one of its city commissioners raised concern after reading about potential issues via internet-based articles. The city commission voted 3-2 to discontinue adding fluoride to the city's water, despite a recommendation by the city's water superintendent to continue fluoridation. In November of that same year, voters reversed the commission's decision with a citywide ballot initiative, with 70 percent of voters voting to reinstate the process.
In 2011, Hartland Township decided to remove fluoride from its water. The issue was apparently based on budget matters – and not health.
Sutton said in 2011, the city of Mount Clemens decided to discontinue fluoridation.
“They are having talks to reintroduce it,” she said. “It wasn't a vote of the people, but based on the budget and equipment costs. They are having talks to reintroduce it and speaking with the Macomb County Health Department. They are inquiring if there are funds available for equipment. The main question is equipment, and they have to replace it and didn't have the funding to do so.”
Sutton said the only location in Michigan where fluoride is naturally occurring to the point that it is hazardous is in Iron Mountain.
“That's the only spot in Michigan that comes close to exceeding, and it's posted. You can't drink it.”
She said there aren't any locations in Michigan where fluoride is actually removed from the water.
“Fluoride is included in water quality reports. That's required,” Sutton said. “It doesn't fluctuate that much. It could depend on where they are getting water and the temperature of the water.”
Christine Farrell, director of the MHHS oral health program, said while fluoridation materials aren't costly, the equipment is.
“Equipment is always a little more expensive. The material is negligible. In doing the equipment, in a lot of places they have to have a separate area to install it, and probably some physical plant changes. Mount Clemens had fluoridated for a long time.”
In terms of fluorosis, 2010 MHHS records show that of the 2000 children tested for incidents, only one showed evidence of any mild fluorosis, Sutton said.
Still, there remains concerns about fluoridation of water in and around the metro Detroit area. Across the Detroit River, the city of Windsor, Ontario, recently decided it would begin fluoridating its water, after deciding to remove fluoride in 2013. The measure is expected to cost about $850,000. The city shares its water supply with Tecumseh and LaSalle.
Those opposing water fluoridation point to studies that show the rate of dental cavities has dropped in other countries that don't fluoridate their water. However, Pollick, with the University of California, said other countries get fluoride from dental products and other forms, including salt.
“They have fluoridated salts in many countries, the way we have iodized salt. In Germany, you can buy both,” he said. “There are lots of products that are fortified with something, such as milk, bread and orange juice. Why does most of Europe not fluoridate? It's a matter of history. Switzerland was on the forefront of iodized salt, and fluoridated salts. If water was being done, they would get a double dose. There are individual reasons in different countries.”
In the United States, Pollick said, the greatest concerns is with infants and ensuring they don't get too much fluoride. As such, the American Dental Association and American Academy of Pediatrics recommend children with developing teeth only use a pea-sized amount of toothpaste when brushing. Further, infants fed formula made primarily with fluoridated tap water could be at higher risk of fluorosis.
“The Centers for Disease Control recommends that people can mix formula with fluoridated tap water, but if they are concerned, they can alternate with distilled water that wouldn't have fluoride,” he said. “Of course, the recommendation is for all to be breastfed, but not all mothers are capable of doing that.
“I'm much more concerned about those parents who are phobic about fluoride and don't want to provide any. Especially low income families, because they are much more susceptible to tooth decay, for various reasons.”
Despite assurances, anti-fluoridation groups like FAN and others who oppose the process remain unswayed. Connett, with FAN, said he opposes fluoridation at any level.
“I don't believe there is a safe level in water,” he said. “The only safe level in water is zero.”
Meanwhile, while additional research is ongoing, Gonzalez-Cabezas said it's important for people to recognize the difference between systemic fluoride exposure and topical exposure.
“Most of the effect when brushing is topical and is spit out, and there's little controversy about that,” he said. “There could be some. Some people are concerned no matter what. Water fluoridation is one that some more people are concerned about because you ingest it.”
While Gonzalez-Cabezas said there is some mild fluorosis in the United States, the benefit of fluoride in water is evident when looking back several generations, when most adults were toothless by the time they were seniors. Still, he said, it's important to understand the reasons why people are opposing fluoridation, even if the claims aren't as alarming as they seem
“Remember, these people are trying to do it for the right reasons,” he said. “They want to live a healthy life, so keep that in mind.”