Facing up to Fluoride.

It's in Our Water and in Our Toothpaste. Should We Worry?

Since the 1940s, municipal water supplies across the United States have been routinely dosed with fluoride. Even if you don,t live in the half of America that adds fluoride to the water supply to help prevent tooth decay, low doses of fluoride occur naturally in virtually all water. It's routinely added to toothpaste as well, which provides a route for small children to ingest it regularly. It's hard to drink, swim or brush your teeth in this country without being exposed to this highly toxic chemical.

Recently released government documents reveal that the scientists who first asserted that fluoride was both a good cavity fighter and harmless to human health were associated with the bomb-making Manhattan Project, which found itself with large stockpiles of toxic fluoride (an unwanted byproduct of manufacturing weapons-grade plutonium and uranium). A convenient disposal option--the nation's municipal water supply--allowed the nuclear scientists to avoid a hazardous waste storage problem similar to that encountered by low-level nuclear power waste (which, conveniently enough, can and is being used to kill bacteria in food).

According to Waste Not magazine, atomic scientists helped design and implement a groundbreaking water fluoridation study in Newburgh, New York, from 1945 to 1956. The results of that study were classified until recently. One uncovered document, however, suggests that fluoride "may have a rather marked central nervous system effect."

The Cancer Risk

Putting aside the question of how fluoride got into the water supply, is our massive national experiment with this chemical worth the risk? Some say yes. Water fluoridation is "a remarkably efficient way of controlling dental [cavities] at the community level," says Dr. Lawrence Furman, a scientist at the National Institute of Dental Research. A 1991 study by the Public Health Service credited fluoridation with reducing cavity rates by 20 to 40 percent. But questions persist about fluoride's role as a carcinogen. Dr. Robert D. Morris, writing in Environmental Health Perspectives, says that chlorine, not fluoride, is the most dangerous carcinogen in water. He links chlorine in the water supply to 5,000 cases of bladder cancer and 8,000 cases of rectal cancer per year in the U.S. "Fluoridation of water has received great scrutiny but appears to pose little or no cancer risk," writes Morris.

Nevertheless, water fluoridation remains highly controversial, especially in the wake of a 1990 National Toxicology Program study that dosed lab rats with fluoride in amounts 25 to 100 times the concentration found in the municipal water supply. While the female rats were given a clean bill of health (aside from teeth discoloration), the male rats showed "equivocal evidence of carcinogenic activity," based on the occurrence of a small number of bone osteosarcomas. The cancers occurred in one in 50 rats when the dosage was at 100 parts per million; it increased to three in 80 at 175 parts per million concentrations.

But those results were achieved with high concentrations of fluoride. Municipal water supplies are optimally fluoridated at a rate of between 0.7 and 1.2 parts per million, and no studies exist to link that dosage with cancer. A recent National Cancer Institute study, which examined 2.2 million cancer death records, found no indication of an increased cancer risk from fluoridation. A year-long Public Health Service study concluded the same thing in 1991.

Good news, assuming Americans are receiving that optimal dose of fluoride. However, Jeff Green, director of the San Diego-based Citizens for Safe Drinking Water (CSDW), thinks that fluoridation monitoring is grossly inadequate, performed largely by industry-supported groups. Green adds that much of the fluoride used in municipal water supplies today is a byproduct of the phosphate fertilizer industry, which has to remove the substance because it's poisonous to plants.

Though the Environmental Protection Agency (EPA) sets maximum contaminant levels for fluoride and officially supports its use in drinking water, there's considerable dissent about the chemical within the agency. In Congressional testimony earlier this year, Dr. J. William Hirzy, representing the EPA professional employees' union, called for a national moratorium on water fluoridation. The practice, he said, is "a massive experiment that has been run on the American public, without informed consent, for over 50 years." Hirzy cited the case of Dr. William Marcus, who was fired from a senior EPA post for going public with concerns about fluoride. Marcus sued the EPA, and was reinstated with back pay. He charged that the dental benefits of fluoride are limited to children three years old and younger, and that in senior citizens its main effect is to double the rate of hip fractures and hearing loss.

Whitens Teeth?

Fluoride is also present in many brands of toothpaste, and recent evidence suggests that children in particular may be getting too much of it. "There probably is excess exposure," says Kit Shaddix, fluoride team leader at the U.S. Centers for Disease Control, which published a 1999 study showing that children are getting dosed on fluoride from drinking water, toothpaste, mouthwashes, fluoride supplements and even grape juice. A 1991 Journal of Clinical Pediatric Dentistry study found fluoride in every sample of bottled fruit beverage tested. A Gerber's grape juice sample contained 6.8 parts per million fluoride, 70 percent higher than the EPA's maximum contaminant level for drinking water.

According to the Wall Street Journal, children are most at risk because fluoride exposure occurs when their teeth are forming, leading to a permanent brown stain called "dental fluorisis" (which now affects 22 percent of American kids). The Canadian broadcaster CBC Radio reports that fluorisis in its mild form affects as many as half of all Canadian kids.

Procter & Gamble, makers of Crest, told reporters that parents of children under six should "supervise" the use of fluoridated toothpaste. But no such reticence is reflected in the Crest "kids' tips" website, which calls fluoride "a naturally occurring substance" and one of the "building blocks of healthy teeth." The site adds that dentists or physicians "may recommend or prescribe additional fluoride treatments." Left unmentioned is the fact that some dentists are now recommending that young children brush their teeth only once a day to avoid excessive fluoride dosage.

The Backlash

Groups like Citizens for Safe Drinking Water are leading a growing movement on the local and state level to get fluoride out of the water supply. The city of Bremerton, Washington voted to keep fluoride out of its water in 1999, joining 78 other U.S. cities that have rejected the additive since 1996. Wilmington, Massachusetts rejected the use of fluoride last March. Wilmington Public Health Director Gregory Erickson used Public Health Service statistics to predict that fluoridated water would lead to 216 children in town schools with moderate to severe fluorisis. "This is a totally unacceptable tradeoff," Erickson said in his own report. He noted that much of the most damaging information about fluoride originates from the EPA itself. "No other drug or medicine has such a widespread application, and yet has had so little scrutiny as to its safety," he concluded.

Fluoride's backers point to high-level endorsements from professional groups, but even some of those are ambiguous. The American Medical Association (AMA), a respected authority that could provide leadership on the issue, takes a rather murky official position. The AMA endorses fluoride application in general, but admits it has not carried out any research work on the subject. Consequently the AMA "is not prepared to state that no harm will be done to any person by water fluoridation."

Given the corporate interest in maintaining the fluoride status quo, there's some evidence that pressure has been exerted to alter scientific findings. Hirzy, in his Congressional testimony, charged that the 1990 National Toxicology Program animal tests that found "equivocal evidence" of cancer was watered down by a "hastily convened" special commission. The initial findings, he said, had described "clear evidence of carcinogenicity in male rats." CONTACT: Centers for Disease Control and Prevention, [phone], www.cdc.gov; Citizens for Safe Drinking Water, [phone], www.citizens.org; National Institutes of Health, [phone], www.nih.gov.

JIM MOTAVALLI is editor of E.