Fluoride is the chemical element with atomic number 9. It belongs to the halogen group, which also includes chlorine, and therefore shares some of its properties. Most notably, it has the ability to capture an extra electron and thus commonly exists as a negatively charged ion rather than in its pure elemental form.
Fluoride is a relatively common element, ranking as the 13th most abundant element in nature. Like most elements, it is also considered essential, meaning it is needed for human health and must be obtained through our diet. However, it is only required in very small amounts. Overexposure—and the threshold is relatively narrow—can lead to the poisoning condition known as fluorosis. In areas with naturally high levels of fluoride in the soil, toxic effects have even been observed in livestock grazing there.
Fluoride is best known through fluoride-containing toothpastes and fluoride rinses used in schools.
Fluoride and the Atomic Bomb
But this article is less about the importance of fluoride itself and more about how science was forced to sacrifice its integrity when far greater national security interests were at stake.
During the Second World War, the U.S. government assembled many of the world’s leading nuclear scientists, including Albert Einstein and Enrico Fermi, to develop atomic weapons. The effort became known as the Manhattan Project (see 2000-Talets Vetenskap, No. 98:1). The objective was to produce enough nuclear fuel from either uranium or plutonium to exceed the critical mass required for a nuclear explosion.
The first step was to enrich uranium by separating the highly radioactive uranium-235 isotope. To separate uranium-235 from uranium-238, it was first necessary to produce a gas, which was achieved using the highly reactive compound uranium hexafluoride (UF₆). Through repeated diffusion processes in specialized chambers, the slightly lighter uranium-235 could then be enriched. The remaining material—the majority of the uranium, uranium-238—is today known as depleted uranium. This enrichment process therefore required large quantities of fluorine.
One of the facilities supplying fluorine for the Manhattan Project was DuPont’s chemical plant in Deepwater, New Jersey. In the summer of 1943, however, a fluorine release from the plant severely affected farmers whose crops and livestock were located downwind. After a night of intense thunderstorms, disaster struck. All the chickens died. The horses became stiff and were unable to work. Some cows were so severely affected that they could no longer stand and instead lay on the ground while eating.
Those who understood the situation realized that it was fluoride poisoning—but the incident could not be made public because the country was at war. Any indication that fluorine was being used on such a large industrial scale might have led the enemy to suspect that uranium was being processed—and therefore that an atomic bomb was under development. The affected farmers were told that everything would be settled after the war had ended.
The farm workers also suffered health problems. If they ate peaches or tomatoes, which were local specialties, they would spend the entire night vomiting. Similar damage was also observed in the years that followed.
In March 1946, the director responsible for the fluoride toxicity studies wrote to his superiors that there were four major concerns regarding fluoride:
- Damage to the peach orchards dating back to 1944.
- Measurements showing unusually high levels of fluoride in the vegetables grown in the area.
- A report documenting unusually high concentrations of fluoride in the blood of people living in the affected area.
- A report describing severe fluoride poisoning in horses and cattle in the region.
After the war ended, the farmers in the area took legal action, suing both DuPont and the Manhattan Project for the damages caused by the fluoride emissions.
The farmers’ protests challenged those in power
Although this environmental incident was limited in scope and highly localized, it nonetheless shook the authorities. Several secret meetings were held in Washington involving scientists and senior officials from the U.S. Army, the Manhattan Project, the FDA (the U.S. Food and Drug Administration), the Departments of Agriculture and Justice, officials responsible for the U.S. chemical weapons program, and DuPont’s attorneys.
The notes taken during these meetings were classified and were not released until the late 1990s. They reveal that the American establishment had united to oppose the farmers. Clearly, those involved considered it of the utmost importance that the secrecy surrounding the development of the atomic bomb be preserved at all costs. A damages lawsuit in a local court would have made the matter public and, in turn, risked alerting other nations to the United States’ ongoing atomic bomb program.
At that time, no other country had yet tested an atomic bomb, and the Americans themselves regarded the weapon as essential to maintaining the United States’ leading position in the world. During the discussions, when the FDA proposed that crops from the fluoride-contaminated area should be confiscated, DuPont opposed the measure, arguing that ”it would create a psychological reaction.” Instead, new samples would be collected in the affected area—but not by the Department of Agriculture. The sampling would instead be carried out by the Army’s Chemical Warfare Service.
A brilliant solution: Prove that fluoride is beneficial
The people living in the affected valley were not satisfied; they were deeply concerned about fluoride-related health damage. The authorities, however, came up with what they believed was a solution to the problem. They would simply produce and present research showing the opposite—that fluoride was beneficial to health, especially for teeth. If that could be demonstrated, no lawsuit would take place, and the farming families’ concerns would subside. In the meantime, those affected received small payments of $200 each to keep them calm. Attorney Jacqueline Kittrell summarized the situation as follows: ”Had the farmers prevailed in their claims, it would have opened the door to additional fluoride lawsuits, which could have delayed the entire ongoing atomic bomb program.”
Instead, the University of Rochester was awarded substantial funding to investigate how safe fluoride is in small doses and what beneficial effects it might have on health.
Likewise, New York College received continued grants worth millions to study the toxic effects of atomic bomb ingredients such as uranium, plutonium, beryllium, and fluoride. The purpose was to enable those working directly with these substances to handle them with a reasonable degree of safety. The research was funded by the U.S. Department of Defense and the Atomic Energy Commission (AEC).
Research was therefore commissioned to demonstrate that fluoride—at least in low doses—was beneficial to health. According to the text, the motivation was not concern for children’s dental health, but rather to satisfy the national security interests associated with the military’s atomic weapons program.
Program F
The new area of research was designated Program F and was closely supervised by the military. As part of the program, fluoride was added to drinking water in order to use large population groups as research subjects. The first test site was Newburgh, New York. The studies there were led by Dr. Harold C. Hodge and had already begun in 1945. Blood samples and placentas were sent to the University of Rochester laboratories for analysis. The first official report, published in 1956, concluded that small amounts of fluoride were safe for the public.
When Newburgh’s current mayor, Audrey Carey, learned about the experiments, she said, ”I am shocked—there are no words to describe it. It reminds me of the Tuskegee experiments conducted on Black farm workers in Alabama.”
Carey herself was a child in the early 1950s, and she recalls being examined by doctors involved in the project. They studied the condition of her teeth as well as an unusual fusion of two finger bones in her left hand.
The findings compiled by Harold Hodge would go on to become the guiding standard for many years to come. An embarrassing aspect of the matter was that the exposure limits he calculated were originally based on the American unit of weight, the pound. When these limits were later converted to the international standard, the numerical values themselves were not changed—they remained the same even though the unit of measurement had been changed to kilograms.
The studies were manipulated
It can now be established that the military exercised significant influence over the researchers, following the declassification of documents related to the case. However, some documents are still entirely missing.
One of the available studies concerns employees who worked on producing fluoride for the atomic bomb program. The original version of the report—which remained classified until a few years ago—differs in several important respects from the edited version that was published in the Journal of the American Dental Association (JADA) in 1947.
The classified report states that most of the workers had lost all of their teeth. In the edited version, this was changed to say that they had no cavities.
The classified report also states that the workers had to wear rubber boots because fluoride fumes dissolved their toenails if they wore ordinary shoes. This passage was omitted from the published version.
The classified report further states that fluoride may have had the same harmful effect on the workers’ teeth and may have contributed to their tooth loss. This statement was also removed from the edited version.
Instead, the published version concluded: ”The men were unusually healthy, both in terms of their general physical condition and their dental health.”
After comparing the classified report with the published version, toxicologist Phyllis Mullenix commented:
”This makes me ashamed to be a scientist. One can only wonder whether the other safety studies on fluoride were conducted in the same way.”
This summary is based on an article written by medical journalists Joel Griffiths and Chris Bryson for the Christian Science Monitor in 1997, which was ultimately rejected for publication.
Ingemar Ljungqvist, Fluoride – A poison we are supposed to have in our toothpaste?
