This year marks the 75th anniversary of artificial fluoridation of the public water supply, a controversial program that affects what is arguably our most basic public good.
Opponents of fluoridation claim it causes a long list of health problems, from hypothyroidism and ADHD to cancer and acne. But it can be hard to fathom why government officials and the entire mainstream dental establishment would promote the addition of fluoride to public water supplies if there is scientific evidence of harm.
If fluoride is as hazardous as critics claim, why has it been endorsed by so many respected health authorities for over 70 years?
Even opponents of fluoridation find it difficult to answer this question without resorting to unfounded conspiracy theories. But the motivating forces behind fluoridation become apparent once an overlooked footnote of American history comes to light: the complex pollution story at the heart of public water fluoridation in the United States.
Many Americans are surprised to learn that fluoride is a common and highly toxic form of air pollution. In its 1971 handbook on airborne pollutants, the U. S. Department of Agriculture (USDA) begins its chapter on fluoride with a simple statement of fact: “Airborne fluorides (F) have caused more worldwide damage to domestic animals than any other air pollutant.”
Because fluoride is a common element deep in the earth’s crust, it is a byproduct of many industrial manufacturing operations, from aluminum and iron factories to brick kilns and phosphate fertilizer plants.
Public health officials in Europe were first to document the negative health effects of fluoride air pollution when they observed its debilitating impact on local factory workers. Symptoms included skin rashes, gastrointestinal ailments, respiratory conditions and a bone disorder called osteosclerosis.
In the mid-twentieth century, the Deputy Health Commissioner of Denmark, a medical doctor named Kaj Roholm, quickly became the world’s foremost authority on fluoride toxicity. In 1937, he published his seminal work on the subject entitled Fluorine Intoxication.
Roholm was aware that dental researchers in the United States were studying fluoride’s effect on teeth. They had recently discovered that excess fluoride in the diet causes a disfiguring of the tooth enamel called dental fluorosis, but some were also suggesting dietary fluoride might inhibit tooth decay. Roholm disagreed.
The final chapter of Kaj Roholm’s book concludes with an italicized warning: not only is fluoride not necessary for healthy tooth enamel, he writes, “but on the contrary, the enamel organ is selectively sensitive to the deleterious effects of fluoride.”
With industry-funded scientists at the forefront, research on fluoride in the United States took a different turn. Corporate polluters were acutely aware of the high amounts of fluoride released into the environment from their manufacturing processes. It was H. V. Churchill, the chief chemist for the Aluminum Company of America (Alcoa), who is credited with the discovery that fluoride in water is the cause of dental fluorosis.
Another industry chemist, Francis Frary, was responsible for prompting the initial research on the idea that fluoride might be beneficial to teeth. The notion ran contrary to public opinion at the time, as many communities were focused on decreasing the amount of fluoride in water because of dental fluorosis.
Federal guidelines issued by the U. S. Public Health Service (PHS) restricted fluoride levels to 1.0 parts per million, or ppm. The current limit set by the Environmental Protection Agency is four times that amount.
Moreover, the first proposal to add fluoride to public water supplies was made by Gerald Cox, a former researcher for Alcoa whose work on cavities was funded by the sugar industry.
These scientists who worked for one of the biggest fluoride polluters in the world are scarcely mentioned in modern tellings of the history of fluoridation. Instead, in the official “Story of Fluoridation” told on the website for the National Institute of Health (NIH), the role of corporate polluters is obscured by the presence of public health dentists.
According to the NIH version of events, the scientists behind fluoridation were two dentists named Frederick McKay and H. Trendley Dean. McKay is cited as readily observing the fact that tooth enamel with dental fluorosis was “inexplicably resistant to decay,” while Dean is credited with first proposing the hypothesis that fluoride added to water would prevent cavities.
As the NIH story goes, Dean longed to test his fluoride hypothesis and “got his wish” in 1945 when officials in Grand Rapids, Michigan agreed to add the chemical to their water supply.
This is a nice origin story — and perhaps it’s the way Dean himself remembered it decades later when he was being lauded as the “father” of one of the “greatest public health achievements of the twentieth century”— but this version of the history of fluoridation is not supported by contemporaneous historical evidence.
An extensive series of letters between Dean and McKay reveals the evolution of their thinking on fluoride. The letters are housed at the U. S. National Library of Medicine in Bethesda, Maryland where they were dug up by former BBC journalist Christopher Bryson while researching for his book, “The Fluoride Deception.”
Throughout the 1930s, the years between when fluoride was identified as the cause of dental fluorosis and the first call to add fluoride to public water supplies, there is not a single mention of the “inexplicable” resistance to cavities the NIH story claims McKay readily observed.
Instead, for the first several years after fluoride’s effect on tooth enamel was discovered, Dean and McKay spent a lot of time discussing the toxic limit for fluoride in water, a level they came to identify as roughly 1.3 ppm (PHS would later cite 1.2 ppm as “optimal”). By the end of the decade, it was still not clear to McKay whether fluoride might accelerate cavities rather than prevent them.
But by 1940, one thing was clear to both Dean and McKay: someone was sensationalizing their research on fluoride in the press.
In multiple letters, the two dentists lament how fluoride and its effect on teeth was being portrayed in the media:
“I fail to see why there should be such public interest in a paper that reaches no conclusions and makes no recommendations,” Dean wrote.
“I agree it is inopportune just now to represent that method of dealing with [cavities] with so much assurance,” McKay responded.
Even just a few months before the commencement of the first fluoridation trial in Grand Rapids — an endeavor Dean oversaw as the head dentist at the U. S. Public Health Service — a government transcript Bryson uncovered in his research shows Dean was against public fluoridation trials because of a lack of safety studies.
“We’ve looked at nothing but teeth,” Dean warned.
In the transcript of the meeting that took place in April, 1944, Dean expressed concern that long-term exposure, even to low doses of fluoride in drinking water, could have negative health effects. For example, he mentioned evidence of increased risk for cataracts and questioned the cumulative effect of fluoridated drinking water on people with impaired kidney function.
Despite Dean’s opposition, local authorities voted to start the trial anyway. They pointed to public pressure as a driving factor in their decision:
“As you know, public interest in it has been very great through the publicity which was given out before we got into it at all… if communities are getting ready to do it, it had far better be done under careful control conditions…”
Once the Grand Rapids fluoridation trial was underway, other cities quickly followed suit, including the nearby city of Muskegon that was intended to serve as a control.
Despite the lack of a control group, the U. S. Public Health Service endorsed fluoridation as safe and effective in 1950, just five years into their 15-year study. Within months, other health authorities such as the American Dental Association (ADA) and the American Medical Association (AMA) released similar statements endorsing the safety of fluoridation, even though they did not conduct safety studies of their own.
Now that local municipalities across the country were told to add fluoride to public water supplies, industry had a profitable market for their fluoride air pollution. (In a letter written decades later, the EPA Deputy Assistant Administrator for Water described fluoridation as “an ideal environmental solution to a long-standing problem.”)
Critics of artificial water fluoridation point to the fact that industry was now profiting from the sale to water municipalities of their former hazardous waste product, hydrofluorosilicic acid, as evidence that corporate polluters were behind the government’s rush to endorse fluoridation.
Yet even with this new national market for fluoride chemicals, the financial interests behind fluoridation were exponentially greater than any profit corporate polluters stood to gain from the sale of hydrofluorosilicic acid.
Part two of our series on the pollution story behind fluoridation explores the deeper monetary incentives held by American industry regarding fluoride in the mid-twentieth century, including why corporate leaders believed the future of their industries — and thereby, national security — relied on the government’s declaration that long-term exposure to low doses of fluoride is safe.
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