The Neurotoxicity Of Fluoride In Drinking Water

Sodium Fluoride is currently added to the majority of municipal water systems in the U.S. to prevent cavities in children. Its use has risen rapidly since the 1950,s. Sodium Fluoride is also registered with the EPA as a rat poison, although advocates say its use in low levels in water poses no adverse health concerns. There has been considerable research done on fluoride regarding cancer, birth defects, and risks to the respiratory, gastrointestinal, and urinary systems, however, very little has been done on its neurological effects.

First Study to Find Neurological Deficits After Fluoride Exposure

Chinese investigations have shown levels of fluoride in drinking water at levels of 3-11 ppm affect the nervous system without first causing physical malformations. Another Chinese study found Attention Deficit Disorders in adult humans if sublingual drops containing 100 ppm of sodium fluoride were administered. Sources of fluoride exposure include processed beverages, toothpastes, mouth rinses, dietary supplements and food. This is an exposure level potentially relevant to humans because toothpastes contain 1000 to 1500 ppm fluoride and mouth rinses contain 230-900 ppm fluoride.

In the 1995 article appearing in the journal Neurotoxicology and Teratology, Dr. Phyllis J Mullenix states,

"Still unexplored, however, is the possibility that fluoride exposure is linked with subtle brain dysfunction. This is the first study to demonstrate that central nervous system output is vulnerable to fluoride, that the effects on behavior depend on the age at exposure and that fluoride accumulates in brain tissues. Of course behaviors per se do not extrapolate, but a generic behavioral pattern disruption as found in this rat study can be indicative of potential for motor dysfunction, IQ deficits and/or learning disabilities in humans. Substances that accumulate in brain tissue potentiate concerns about neurotoxic risk."

Dr. Phyllis J. Mullenix
Toxicology Department, Forsyth Research Institute, Boston, MA
JOURNAL TITLE: Neurotoxicity of Sodium Fluoride in Rats
SOURCE: Neurotoxicology and Teratology, 17(2), 1995