It might be in every glass of water you drink-tasteless, colourless and odourless. It might be saving your teeth from cavities, or slowly poisoning you.
It might be in every glass of water you drink tasteless, colourless and odourless. It might be saving your teeth from cavities, or slowly poisoning you. Most public health officials and dentists don't question its benefits, while a few scientists have argued against its use. "It" is fluoride, a compound added at about one part per million (ppm) to municipal water supplies from which just over half of us drink.
Leading proponents of water fluoridation include dental associations and government public health agencies. The American Dental Association calls fluoride a "nutrient" and the "key reason" why tooth decay has declined in the past few decades. The Canadian Dental Association claims that "Where fluoride has been added to municipal water supplies, there has been a marked decline in tooth decay rates between 35 and 50 percent in children and 30 percent in adults," and that "Children need fluoride protection while their teeth are developing." Health Canada echoes these assurances.
However, there is another side to the story that prompts the question of side-effects, the least of which is dental fluorosis, a mottling or pitting of the teeth that most official organizations dismiss as cosmetic. Indeed, some scientists and public health officials oppose water fluoridation. Dr. Hardy Limeback, head of preventive dentistry at the University of Toronto, is one of them; he has publicly criticized the practice since April 1999. John Colquhoun was New Zealand's top promoter of water fluoridation until a world-study tour in 1980, during which he realized improvements in dental health were already occurring in unfluoridated areas, begging the question of fluoride's effectiveness. Paul Connett is a chemistry professor at St. Lawrence University in Canton, New York. His opposition began while doing some research when his town proposed to stop fluoridating in the mid-1990s. He was a founding member of the Fluoride Action Network and now manages a comprehensive anti-fluoridation Web site at fluoridealert.org. Even the union of scientists within the US Environmental Protection Agency voiced its opposition in 1999.
Reasons For Concern
The key issues surrounding water fluoridation involve safety and effectiveness. Water fluoridation results in systemic bodily exposure to fluoride (yet the purported benefits of fluoride are mainly topical, on the tooth surfaces). Fluoride is absorbed by some organs and body systems, notably bones, and this can be quite harmful. There is evidence of an elevated risk of bone fractures and degenerative bone disease in fluoridated areas, and the risk of bone cancer (osteosarcoma) is 40 percent higher in fluoridated areas in Ireland and three times higher in fluoridated counties in New Jersey.
Among children with dental fluorosis, Chinese scientists have found lower IQ scores. Polish scientists have found bone structure disturbances. Epidemiological studies in the US have shown a higher risk of Down's syndrome, particularly among young mothers, in the most highly fluoridated areas.
In addition to concerns of fluoride exposure, heavy metals (lead, arsenic and radium, among others) are common contaminants of the silicofluorides that most Canadian cities add to their water supplies. The levels of heavy metals are usually only around one part per billion (ppb), but this is still enough to have negative effects, particularly as they accumulate in the body over years. Arsenic, often the most concentrated heavy metal contaminant, is associated with cancer and is particularly toxic to the liver, kidneys, and nervous and circulatory systems. Studies on more than 400,000 children have consistently found elevated lead levels in children consuming water that contains silicofluorides. Lead is a potent neurotoxin and, according to Limeback, can increase cavity rates. Radium is associated with an elevated risk of leukemia and bone cancer.
The Effectiveness Question
The prime reason fluoride is added to water is to prevent dental decay. Indeed, several studies have shown that rates of dental decay declined after fluoridation. But this is misleading because dental decay rates have also been going down in unfluoridated areas and were often declining before fluoridation was initiated.
Limeback feels that if there is a benefit of water fluoridation, it is "miniscule and clinically irrelevant." When Durham, North Carolina had an 11-month break in water fluoridation, for example, there was no discernible difference in cavity rates, but a significant reduction in dental fluorosis. Similar results were found when fluoridation was stopped in La Salud, Cuba and several East German cities.
Even the Ontario government noted in a 1999 report prepared by Dr. David Locker of the University of Toronto's faculty of dentistry that "The magnitude of the effect [of] is not large in absolute terms, is often not statistically significant and may not be of clinical significance."
Lack Of Clinical Proof
There have been no randomized, placebo-controlled trials of water fluoridation. Epidemiological, observational studies are affected by other factors such as differences in diet, environmental factors, breastfeeding rates or dental care in the towns being compared. This fact alone should mean that debating against water fluoridation is reasonable and scientifically defensible.
Besides, simple, effective and safer alternatives to water fluoridation do exist. Breastfeeding promotes proper jaw formation and prevents baby bottle tooth decay. Good nutrition with lots of raw fruits and vegetables also promotes good dental health, as does avoiding excessive sugar consumption, especially from acidic drinks such as pop, particularly for children. Non-toxic additives to dental products such as Xylitol can, according to Connett, provide many of the benefits of fluoride, without the risks. (Fluoridated toothpaste labels in the US actually carry health warnings.)
In conclusion, we don't know everything about fluoridation. Yet, we know enough about its negative effects and lack of proven effectiveness to remain skeptical and not blindly accept hand-waving assurances from public health officials.
Fluoride contributes to environmental pollution. Much is dumped into the air by industries such as aluminum, phosphate fertilizer, nuclear energy and those burning coal. The US Department of Agriculture claims that airborne fluorides have "caused more worldwide damage to domestic animals than any other air pollution."
Some people would call it very convenient that the municipal use of fluoride really, an industrial waste product turns a potentially enormous disposal expense into a profit. Waste scrubbed from phosphate fertilizer smokestacks to reduce air pollution is now distributed into the water supply, apparently under the belief that toxic waste becomes a nutrient if diluted enough.
Yet, dosage is another key issue. Water fluoridation allows little control over the amount that individuals actually consume. Some people, such as athletes and people working outdoors in hot climates, may consume vastly more fluoride than expected. People also vary significantly in their tolerance, particularly if they have reduced kidney function or other conditions. In other parts of the world, particularly India, levels of fluoride are naturally high, so their water requires de-fluoridation to prevent widespread bone disease.
Just more than half of Canadians drink fluoridated water. If you live in one of Canada's 10 largest cities except Vancouver and Montreal you're most likely getting regular doses. Many rural areas also fluoridate; check with your local water authority. However, some cities are fighting fluoride. An intense debate occurred in 1998 in Calgary. Even with the publicly funded, slick advertising campaign of pro-fluoridationists, only a slim majority of Calgarians voted to continue fluoridation. In Kamloops, however, 63 per cent voted to stop fluoridation in 2001. Similar rejections occurred recently in Cobalt, Ont., and Squamish, BC.