Why Natural Fluoride and Synthetic Fluoride Are Not Created Equal
In this series, “America, the Fluoridated,” we explore the contentious findings surrounding fluoridation of the U.S. public water supply and answer the question of whether water fluoridation poses a risk and what we should do about it.
Previously: Fluoridation of the U.S. public water supply has been a polarizing topic both academically and politically since its start in the 1940s. Debate over its benefits and health risks has raged on as the science has continued to unfold. While some studies indicate water fluoridation can reduce cavities, others link it to side effects, including cognitive issues in children.
Water fluoridation is controversial for more than its potential adverse events on people; there are also concerns about how the fluoride used in water is produced.
Not all fluoride is created equal. Naturally occurring fluoride, such as calcium fluoride (CaF2), is released into the soil as weathered crustal rock and minerals dissolve. The fluoride is then picked up by any source of water and some plants, including those we eat.
Naturally occurring calcium fluoride has the potential to cause health problems with prolonged intake or overconsumption. There are regions in the world where high amounts of calcium fluoride cause major health issues.
A 2020 article in The Lancet reported that calcium fluoride not only contaminates the drinking water in India, but also leaches into food and spices.
As a result, in some parts of India, prolonged intake of calcium fluoride has resulted in an outbreak of skeletal fluorosis, a condition that leads to joint calcification, discomfort, and deformity that can lead to permanent disability. Dental fluorosis, which makes the teeth appear discolored and mottled, is also a side effect of prolonged or overconsumption of this natural chemical.
The article warns that more than 60 million people are possibly at risk of calcium fluoride contamination in India.
The fluoride additives in our public water system aren’t the naturally occurring calcium fluoride (CaF2), however.
The Centers for Disease Control and Prevention (CDC) says community water systems in the United States use one of three artificial chemical fluoride additives for community water fluoridation:
- Fluorosilicic acid (H2SiF6; also referred to as hydro fluorosilicate, FSA, or HFS), the form used by most water systems in the United States
- Sodium fluorosilicate (Na2SiF6)
“Since the early 1950s, FSA has been the main additive used for water fluoridation in the United States. The favorable cost and high purity of FSA make it a popular additive,” the CDC states.
According to the American Water Works Association Standards Committee on Fluorides, approximately 90 percent of fluoride additives used in the United States are produced during the process of extracting phosphate from phosphoric ore.
The CDC explains this process on its water fluoridation additives information page. Phosphate rock is heated with “sulfuric acid to produce a phosphoric acid-gypsum (calcium sulfate-CaSO4)” mixture, and the “phosphoric and fluoride gases that are released in the process are then separated.” The fluoride gas is captured and used to create fluorosilicic acid.
The three fluoride additives used for water fluoridation are derived primarily from phosphate fertilizer production, according to the CDC. Although some counties such as Harford, Maryland, get their chemical fluoride additive from the toxic gaseous discharge from aluminum factories as well, as stated in their 2021 water quality report.
According to the peer-reviewed “Toxicological Profile on Fluorides, Hydrogen Fluoride, and Fluorine” from the Agency for Toxic Substances and Disease Registry, when materials are burned that contain fluoride, such as phosphate rock, the gas byproduct that is created is called hydrogen fluoride.
The profile states that “hydrogen fluoride is one of the 189 chemicals listed as a hazardous air pollutant (HAP) in Title III, Section 112 of the Clean Air Act Amendments of 1990.”
Also, the chemical process of creating phosphate fertilizers, which in turn creates the toxic, gaseous byproduct that is added to our drinking water, has been highly scrutinized for significantly increasing the discharge of toxic and harmful compounds into the environment.
Because of the major environmental impacts of agricultural phosphorus use—and the hazardous chemical gas emitted from the manufacturing process—at least 11 states have banned phosphorus fertilizer use or sale, including Illinois, Maine, Maryland, Michigan, Minnesota, New Jersey, New York, Vermont, Virginia, Washington, and Wisconsin.
The Fluoride Action Network says that in recent years, an increasing number of water departments have begun purchasing their fluoride chemicals from China. The organization warns that “the quality control of the Chinese chemicals is even more lax, and variable, than the U.S.-produced chemicals.”
Synthetic Chemicals Added to Water
What are these synthetic chemicals that are added to our public drinking water?
The National Oceanic and Atmospheric Administration (NOAA), a science-based federal agency within the Department of Commerce, lists the properties of each of the three artificially made fluoride chemical additives.
The chemical data sheets provided by the NOAA detail some notable attributes:
Fluorosilicic Acid
General Description: “A colorless fuming liquid with a penetrating pungent odor. Corrosive to metals and tissue. Both the fumes and very short contact with the liquid can cause severe and painful burns. Used in water fluoridation, in hardening cement and ceramics, as a wood preservative.”
This chemical requires the hazard label “corrosive,” and workers handling it are required to wear protective clothing, rubber gloves, and safety glasses.
Fluorosilicic acid solutions are used in electrolytic refining of lead, in electroplating, for crumbling lime or brickwork, for removal of lime from hides during the tanning process, for removals of molds, and as a preservative for timber.
Sodium Fluorosilicate
General Description: “A fine, white, odorless, powdered solid. Toxic by ingestion, inhalation, and skin absorption. Used as a rodenticide.”
This chemical requires the hazard label “Poison,” and workers handling it are required to wear a dust respirator, protective gloves, and goggles or a face shield.
Sodium Fluoride
General Description: “A colorless crystalline solid or white powder, or the solid dissolved in a liquid. It is soluble in water. It is noncombustible. It is corrosive to aluminum. It is used as an insecticide. It is also used to fluorinate water supplies, as a wood preservative, in cleaning compounds, manufacture of glass, and for many other uses.”
This chemical requires the hazard label “Poison,” and workers handling it are required to wear personal protective clothing and eye protection.
Changing Levels
In January 2011 the Department of Health and Human Services (HHS) update and replace the 1962 U.S. Public Health Service Drinking Water Standards recommendations for fluoride concentrations in drinking water to 0.7 mg/L.
Prior to this, the recommended range set in 1962 was 0.7 to 1.2 milligrams per liter. But large sections of the population were suffering from dental fluorosis. A 2018 study published in Preventative Nutrition and Food Science said that between 1999 and 2004, the prevalence of dental fluorosis was 41 percent in American adolescents aged 12 to 15 years.
After a review of new information regarding the high prevalence of dental fluorosis and the relationships between fluoride exposure, bone fractures, and skeletal fluorosis that began in September 2010 by a panel of scientists from across the U.S. government brought together by the Department of Health and Human Services, the recommendation was downgraded to the lowest end of the previous recommended range to minimize fluoride toxicity.
The CDC notes that this recommendation isn’t an enforceable federal regulation. Fluoridation is not required by EPA as it’s prohibited by the Safe Drinking Water Act from requiring the addition of any substance to drinking water for preventive health care purposes.
The CDC provides recommendations about the optimal levels of fluoride in drinking water in order to prevent tooth decay. Individual jurisdictions make their own decisions on whether to fluoridate their community’s water supplies, and some states mandate fluoridation for communities of a specific size.
CDC Argues Artificial Is the Same as Natural
The CDC argues that because studies show that naturally occurring calcium fluoride and synthetic chemical additives have the “same fluoride ion” present, there is no difference in the health effects of fluoride depending on its source or chemical compound.
They back up this claim with two studies. One was a single-blind, crossover study with 10 adults published in June 2008. The study measured three parameters that show how the chemicals are processed in the body: the level of the chemical in the bloodstream after it was ingested; the time it took for the chemical to reach its maximum concentration in the bloodstream after it was ingested; and the amount of the chemical that remained in the bloodstream over a period of time after it was ingested.
This study concluded that in 10 adults, fluoride type (natural versus artificial) didn’t impact how it was metabolized in the body.
Are There Benefits?
According to the CDC, drinking fluoridated water “bathes” the teeth in fluoride-enhanced saliva, thus helping to protect and build surfaces by affecting the activity of cavity-causing bacteria. They say this is a cost-effective way of reaching poorer families who may not have a balanced diet, access to a dentist, or the regular habit of brushing with fluoride toothpaste.
Critics question whether swallowing treated water allows fluoride into our bones and blood where it may be harmful to other parts of the body. They say that we must consider that if fluoride can kill enzymes in tooth bacteria, it could potentially have a damaging effect on other vital enzymes.
In a 2016 report by Harvard Public Health, Philippe Grandjean, adjunct professor of environmental health, states: “We should recognize that fluoride has beneficial effects on dental development and protection against cavities. But do we need to add it to drinking water so it gets into the bloodstream and potentially into the brain?”
He warns that we need basic research to make sure that fluoridation doesn’t cause adverse health risks.
Over the next several articles, we’ll examine the history and politics woven into the beginnings of the fluoridation program, scrutinize the validity of the studies used to start it, uncover suppressed research that challenges its credibility, and analyze contemporary research about the toxicity risk.
In the next article:
In 1945, the first real-world experiment commenced in Grand Rapids, Michigan, making it the first city in the world to fluoridate its drinking water.
This initial trial was supposed to last 15 years before any potential recommendation for the expansion of water fluoridation to other communities but, the city of Madison, Wisconsin began adding synthetic fluoride to the public water in 1948, at the direction of the Common Council.
By June 1950, the Surgeon General declared that any community wishing to fluoridate its water supply should be “strongly encouraged” to proceed, as noted in the CDC timeline.
