Roger D. Masters
Research Professor, Dartmouth College

Controversy over "fluoridating" public water supplies has been on the agenda for half a century. Although the specific chemicals in use raise genuine scientific questions, most proponents (from the Surgeon General to the American Dental Association) and critics talk about "fluoridation" without discussing the difference between sodium fluoride, familiar in toothpaste, and fluosilicic acid or sodium silicofluoride (jointly called "silicofluorides"), which are the main chemicals used for water fluoridation in the U.S. Does the difference matter? If so, why does a long-delayed CDC report on fluoride treatments carefully list the chemicals in fluoridated gels and mouthwash, but refuse to mention the chemicals used in our water supplies?

Water fluoridation was begun in the mid 1940's as a ten year experiment to see if drinking-water with sodium fluoride would reduce tooth decay. All tests of safety were conducted on sodium fluoride. In 1950, however, the Public Health Service authorized the substitution of silicofluorides, even though they had never been tested for effects on health and behavior. Today, over 90% of fluoridated water (delivered to over 140 million Americans) is treated with one of the silicofluorides.

The switch to silicofluorides about 50 years ago may have been an enormous mistake. Three years of intensive research, supported by the Earhart Foundation, has indicated that

1. Silicofluorides have never been tested for health and safety, and the EPA admits it now has no information on the effects of "chronic exposure" to water treated with them.

2. Silicofluorides do not dissociate completely after injection in public water supplies and their biochemical effects are not benign.

3. Extensive data analysis (based on three large samples of over 400,000 children) reveals that where silicofluorides are in use, children absorb significantly higher levels of lead from environmental sources (such as old housing).

4. Additional studies show that where silicofluorides are in use, there are higher rates of behavioral problems that have been linked to lead toxicity (including hyperactivity and other learning disabilities, substance abuse, and violent crime). These findings are based on a "cumulative loading" model of environmental risk factors (for the foregoing see http://www.dartmouth.edu/~rmasters/ahabs.cfm).

The CDC and EPA have constantly refused to support objective scientific testing and have apparently engaged in a cover-up of data suggesting toxicity and harmful effects due to silicofluorides. The pattern evident in prior reports and funding decisions is especially noteworthy in the long-delayed CDC report on "Recommendations for Using Fluroide to Prevent and Control Dental Caries in the United States" (MMWR, Aug. 17, 2001, 50 [RR14] 1-42). This document is silent on the different health and behavioral effects of silicofluoride treated water compared to that treated with sodium fluoride. Although the report identifies the specific chemicals used to add fluoride to mouth rinse (sodium fluoride), dietary fluoride supplements (sodium fluoride), gel and foam (acidulated phosphate fluoride, sodium fluoride, or stannous fluoride) or fluoride varnish (sodium fluoride or difluorsilane), there is no mention of the specific chemicals used to fluoridate public water supplies or toothpaste (the two principal sources of fluoride for caries control).

Given the foregoing information, informed observers suspect that the CDC intentionally omitted information to "cover up" the fact that silicofluorides, although used in over 90th of water fluoridation in the U.S., have never been subjected to the tests conducted on sodium fluoride or other health products and medicines. Some CDC personnel know the research questioning silicofluorides, and in one case attended a presentation of research on their dangers.

It is time to discuss openly a toxin that could well contribute to higher rates of hyperactivity (ADHD) and crime in many American communities. Why should we allow bureaucrats to block discussion of the differences between either fluosilicic acid or sodium silicofluoride (toxic byproducts of manufacturing phosphate fertilizer as well as nuclear fuel and warheads) and sodium fluoride? Since silicofluorides have never been tested, shouldn't there be a moratorium on their use until their safety has been proven? If you live in Manhattan, you can choose non-fluoridated toothpaste but not non-fluoridated water. It's time for Congressional hearings on an issue that could help our children at virtually no cost (except for lost revenue to some chemical corporations and embarrassment to the CDC, EPA, and American Dental Association).

 

##########