The Austin Chronicle

To Your Health

By James Heffley, Ph.D., November 1, 2002, Columns

Q. My city recently voted to begin fluoridation of the municipal water supply. Should I be concerned, and if so, how would I remove the fluoride?

A. Fluoridation has been an emotionally charged controversy for decades, with both sides often resorting to hyperbole in order to win points in the debate. Basically, proponents claim that optimum fluoride intake reduces the incidence of dental caries by 20-60%, especially in children. Opponents point to the toxicity of fluoride, which is on par with arsenic.

Even if the idea that the optimum intake of fluoride reduces cavities is accepted, which those ardently opposed to fluoridation do not, the task of defining "optimum intake" is very difficult. Proponents cite research showing that 1 part per million fluoride in drinking water provides protection from tooth decay, with only about 10% of people exhibiting signs of mild toxicity such as mottling of tooth enamel. Opponents are concerned that over a lifetime this amount of fluoride would cause more serious damage than mottling of tooth enamel. It is generally agreed that approximately one-half of the fluoride that goes in will stay in. So, just as money in a bank can accumulate with repeated deposits, fluoride can accumulate because different individuals deposit and withdraw at different rates.

When drinking water contains about 1 ppm fluoride it is assumed that those who drink the water will obtain about 1 mg per day since most people drink about 1 quart of water per day. There are several problems with this assumption. One is that there are other sources of fluoride besides drinking water. Beverages such as tea often contain fluoride in addition to what is in the water used to brew it. Fluoride-containing pesticides and herbicides leave residues on fruits and vegetables that add to fluoride intake. Also, in recent times, machines remove the meat used in processed foods (hot dogs, sausage, hamburger, etc.) from the bones, producing fluoride-rich bone particles that contribute to total fluoride intake. Fluoridated toothpaste contains 200-500 mg of fluoride per portion, which if swallowed rather than spit out, would make a significant addition to total fluoride intake. Some estimates of today's fluoride intake run between 3 mg and 6 mg per day.

If fluoride is considered a nutrient, it has a "safety factor" of about 2, because 10 mg per day is the generally accepted limit. Conceivably, the amount of fluoride that a 200-pound adult obtains might kill a newborn child.

Some people are against fluoridation of a municipal water supply on the basis that no one should be forced to consume such a dangerous substance and that it should be individually administered if it is needed. Many dentists will give those who need fluoride a prescription for a tablet.

If you would rather not consume fluoridated water, it appears that the larger charcoal water filters available today will remove fluoride, whether naturally occurring or added. The smaller filters that attach directly to your kitchen faucet are too small for this job, but the "countertop" models, which are generally 8-12 inches high and 2-4 inches in diameter, remove about 80% of the fluoride, and larger, "under the sink" models do even better.

If you are comfortable with fluoridated water, simply drink the tap water. If you would rather avoid the added fluoride, most will be removed, along with several unwanted agricultural chemicals, by a charcoal filter.

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