"It's the crime of the century," 82-year-old Len Greenall says, his voice rising in passionate indignation. "It's an immoral invasion of bodily privacy." He's sitting at the dining room table of his Surrey, B.C., home, a heap of files beside him, discussing the evils of municipal water fluoridation, a fight he's waged for 45 years. "It's a very haphazard way of dosing people with a powerful chemical," says Greenall, a former contractor and a member of B.C.'s Health Action Network Society, a Burnaby-based consumer health advocacy group.
Greenall's band of toxic crusaders have been uncommonly successful. The number of British Columbians drinking fluoride-treated water has fallen below five per cent, the lowest provincial rate in the country. Neighbouring Alberta, by contrast, has a fluoridation rate of about 75 per cent. Nationally, according to Health Canada, almost 40 per cent of Canadians receive fluoridated water. But is it necessary, in an age of fluoridated toothpaste, to drink, bathe and irrigate the garden with water laced with a cavity-fighting agent? While critics like Greenall are often shoved to the fringes of the debate, there is also mounting evidence that the quest for a perfect smile can carry the risk of a fluoride overdose.
With childhood dental cavities now a rarity, the benefits of fluoride in strengthening tooth enamel would seem obvious. Moreover, fluoridation has the backing of most of the Canadian medical establishment, including provincial and federal health ministries and the national dental, medical and public health associations. Yet there are some notable defections from the pro-fluoride camp. Among the most influential is Dr. Hardy Limeback, the head of Preventive Dentistry at the University of Toronto. Limeback, who once extolled the benefits of fluoridation to his students, now says "mass medicating" the public through the water supply is dangerous and unnecessary. The benefits are "exaggerated" and there is growing evidence of overexposure from fluoridated toothpaste and other sources, he writes in an e-mailed response to Maclean's. "On the risk side, so many people will end up with ruined teeth, fragile bones, acute sensitivities, thyroid problems and an increased risk for cancer, all in the name of preventive dentistry," Limeback says, "I am ashamed for my profession and can no longer take part in the charade."
Fluoridation is ultimately an issue decided by municipal ballot in most of Canada, and in many localities there is decaying support for its use. Kamloops resident Kevin Millership, for example, is suing both the federal and provincial government in B.C. Supreme Court, seeking damages for dental fluorosis, a pitting and discoloration of the teeth caused by excess fluoride. Millership, who represented himself during a three-week summary trial that finished on Oct. 25, is seeking an end to fluoridation throughout Canada. He claims such treating of the water supply violates several constitutional rights, including those of "life, liberty and security of the person."
Gareth Morley, a lawyer for the B.C. government, countered that fluoridation is constitutional and that it is "justified because this is a public health measure in the interests of dental health." Mr. Justice Robert Powers has reserved judgment in the case, which would have a national impact only if it reaches the Supreme Court of Canada on appeal. Locally, however, the issue is settled. Millership dropped Kamloops from his suit after city residents voted last year to end fluoridation, a practice that had continued for 40 years. Within the past decade local votes have also thrown out fluoridation - often after decades of use - in the B.C. communities of Kitimat, Campbell River, Port Hardy, Squamish, Courtney, Comox and Kelowna. The city council in the Yukon capital of Whitehorse also voted to end fluoridation in 1998 after 30 years.
The debate has its roots in the emotional fluoridation fights of the Cold War era. In 1945, Brantford, in southwestern Ontario, became the first Canadian city to fluoridate. In Toronto, however, legendary broadcaster Gordon Sinclair's vehement campaign against lacing tap water with "poison" delayed that city's fluoridation program until 1963. Montreal has never fluoridated its water, a legacy that began with the refusal of former mayor Jean Drapeau to obey a provincial law requiring fluoridation. Victoria and greater Vancouver have never fluoridated either, in large measure due to the campaigning of Greenall, who is as relentless as a dripping tap.
Now, as then, there are wildly conflicting interpretations of the growing body of science on the subject. Information from the B.C. Ministry of Health calls fluoride "a beneficial nutrient based on its proven, positive effects on dental health." The Calgary Health Region, which rebuffed both an anti-fluoride court challenge and a city plebiscite on the issue in the past decade, says in material posted on its Web site that fluoridation costs just 60 cents per person per year, "a small investment for a lifetime of reduced dental costs." It likens fluoridation to other measures for the common good: "adding vitamins A and D to milk, vitamin C to juice or iodine to salt."
The federal health ministry, while endorsing water fluoridation, is more circumspect. Health Canada guidelines warn that children under age six are at risk of dental fluorosis, which "can cause damage to tooth enamel, resulting in tooth pain and some problems with chewing," especially if they use, and swallow, fluoridated products. Extreme fluoride exposure for adults can result in dense and brittle bones, causing joint pain in mild cases and, in severe instances, "difficulty in moving, deformed bones and greater risk of bone fractures."
Federal warnings are now required on fluoridated dental products. Crest toothpaste, for example, states: "Do not swallow. Children under 6 years of age should use only a pea-sized amount and be supervised while brushing." Colgate's label states: "Recommended for adults and children over 12 years. Do not swallow toothpaste."
Limeback says studies in British Columbia and elsewhere "do not show a significant increase in dental decay among children" in non-fluoridated communities. Yet, he says, there is an "entrenched resistance" by health professionals and municipalities to re-examining the issue. Limeback says he's paid a price since voicing concerns on fluoridation about three years ago. "I have been insulted, attacked verbally, accused of lying to the public and my credibility as a scientist has been brought into question."
The cost of ignoring the debate, however, may carry a higher cost - in litigation, he warns. "If we discover that 50 years of fluoridation has actually harmed the population, the legal implications are enormous."
See also Water Treatment.
Maclean's November 25, 2002