On November 23, 2016, a Toxic Substances Control Act (TSCA) section 21 petition was submitted by the Fluoride Action Network, Food & Water Watch, Organic Consumers Association, the American Academy of Environmental Medicine, the International Academy of Oral Medicine and Toxicology, Moms Against Fluoridation, and certain individuals. The general object of the petition is to urge EPA “to protect the public and susceptible subpopulations from the neurotoxic risks of fluoride by banning the addition of fluoridation chemicals to water”. The specific action sought is a rule, under TSCA section 6(a)(2), to “prohibit the purposeful addition of fluoridation chemicals to U.S. water supplies.”
The petition is focused on the potential for fluoride to have neurotoxic effects on humans; it cites numerous studies bearing on this issue. The petition contends that the purposeful fluoridation of drinking water presents an unreasonable risk to human health from neurotoxicity, and that a ban on this use of fluoridation chemicals is necessary to curtail this unreasonable risk. The following is a summary of the primary support given in the petition for this view:
- Fluoride neurotoxicity at levels relevant to U.S. population. The petition claims that fluoride poses neurotoxic risks to the U.S. population. The petition claims that the cited studies of fluoride-exposed human populations have consistently found neurotoxic effects (lower-than-average IQs) at water fluoride levels below the current Maximum Contaminant Level Goal of 4 mg/L set by EPA’s Office of Water. The petition argues that the difference between the fluoride levels in the United States and the greater levels in rural China (where most of the cited IQ studies were conducted) is “lessen[ed]” by the abundance of fluoridated toothpaste in the U.S.
- Recent epidemiological studies corroborate neurotoxic risk in Western populations. The petition cites two studies from Western populations to attempt to corroborate the assertion that exposure to fluoride in drinking water presents unreasonable risks for neurotoxicity.
- Neurotoxic risks supported by animal and cell studies. The petition argues that studies on both experimental animals and cell cultures are consistent with cited human research linking fluoride exposure with neurotoxic effects in humans.
- Susceptible subpopulations are at heightened risk. The petition argues that certain subpopulations (e.g., infants, the elderly, and persons with nutritional deficiencies, kidney disease or certain genetic predispositions) are more susceptible to fluoride neurotoxicity.
- RfD/RfC derivation and uncertainty factor application. The petition argues that EPA’s 1998 Guidelines for Neurotoxicity Risk Assessment support the need to apply a 10-fold uncertainty factor in deriving an oral Reference Dose (RfD) or inhalation Reference Concentration (RfC).
- Benefits to public health. The petition bases, in part, its claim of unreasonable risk on the assertion that the fluoridation of drinking water confers little benefit to public health, relative to the alleged neurotoxic risks. The petition argues that since fluoride’s primary benefit comes from topical contact with the teeth, there is little benefit from swallowing fluoride, in water or any other product. The petition argues that there is therefore “little justification” in exposing the public to “any risk” of fluoride neurotoxicity.
- Extent and magnitude of risk from fluoridation chemicals. The petition bases, in part, its claim of unreasonable risk on estimates of the extent and magnitude of risk posed to portions of the U.S. population living in areas where artificial fluoridation occurs.
- Consequences of eliminating use of fluoridation chemicals. The petition argues that the risks of fluoride exposure from fluoridated drinking water are unreasonable, in part, because they could be easily and cheaply eliminated, and because alternative products containing topical fluoride are widely available.
- Link to elevated blood lead levels. The petition argues that artificial fluoridation chemicals are linked with pipe corrosion and elevated blood lead levels. The petition interprets data in several studies as demonstrating an association between fluoridation chemicals and elevated blood lead levels.
After careful consideration, EPA denied the TSCA section 21 petition, primarily because EPA concluded that the petition has not set forth a scientifically defensible basis to conclude that any persons have suffered neurotoxic harm as a result of exposure to fluoride in the U.S. through the purposeful addition of fluoridation chemicals to drinking water or otherwise from fluoride exposure in the U.S. In judging the sufficiency of the petition, EPA considered whether the petition set forth facts that would enable EPA to complete a risk evaluation under TSCA section 6(b).
EPA also denied the petition on the independent grounds that the petition neither justified the regulation of fluoridation chemicals as a category, nor identified an adequate section 6 rule as the action sought. Rather than comprehensively addressing the conditions of use that apply to a particular chemical substance, the petition requests EPA to take action on a single condition of use (water fluoridation) that cuts across a category of chemical substances (fluoridation chemicals).
Fluoride has been proven to protect teeth from decay by helping to rebuild and strengthen the tooth’s surface or enamel. According to the Centers for Disease Control and Prevention and the American Dental Association, water fluoridation prevents tooth decay by providing frequent and consistent contact with low levels of fluoride. Thus, the health benefits of fluoride include having fewer cavities, less severe cavities, less need for fillings and removing teeth, and less pain and suffering due to tooth decay.
Fluoride protects teeth in two ways–systemically and topically. Topical fluorides include toothpastes, some mouth rinse products and professionally applied products to treat tooth surfaces. Topical fluorides strengthen teeth already in the mouth by becoming incorporated into the enamel tooth surfaces, making them more resistant to decay. Systemic fluorides are those ingested into the body. Fluoridated water and fluoride present in the diet are sources of systemic fluoride. As teeth are developing (pre-eruptive), regular ingestion of fluoride protects the tooth surface by depositing fluorides throughout the entire tooth surface. Systemic fluorides also provide topical protection as ingested fluoride is present in saliva which continually bathes the teeth. Water fluoridation provides both systemic and topical exposure which together provide for maximum reduction in dental decay.
The Surgeon General, the Public Health Service and the Centers for Disease Control and Prevention reaffirmed in 2015 the importance of community water fluoridation for the prevention of dental caries and its demonstrated effectiveness. In the Public Health Service’s 2015 Recommendation for Fluoride Concentration in Drinking Water, they note “there are no randomized, double-blind, controlled trials of water fluoridation because its community-wide nature does not permit randomization of individuals to study and control groups or blinding of participants. However, community trials have been conducted, and these studies were included in systematic reviews of the effectiveness of community water fluoridation. As noted, these reviews of the scientific evidence related to fluoride have concluded that community water fluoridation is effective in decreasing dental caries prevalence and severity”.