For close to 70 years, some water utilities have added fluoride to their water supplies to help prevent tooth decay in children and adults. Halifax has been doing this since 1956. However, since the beginning of fluoridation, some people have questioned why it is needed.
A 2013 Maclean’s story said more than 30 communities in Canada (including Calgary, Quebec City and Waterloo) have opted to stop adding fluoride since 2005. A recurring theme in the story has been intense pressure from vocal anti-fluoride activists.
The narrative in the fluoridation debate has been driven by the anti-fluoride movement, which has argued its position on both scientific and moral grounds, claiming amongst other things, fluoridation does not prevent cavities in children and adults, it lowers the IQ of children and is the equivalent of mass medicating a population. Critics, however, say proponents are relying on bad science.
The debate has arrived in Halifax. An anti-fluoride group called Safe Water Halifax has collected almost 500 signatures on an online petition to stop water fluoridation. Last November, the group’s founder published an opinion piece in the Coast with the headline “Halifax Water should stop poisoning us.”
“The passion of the anti-fluoride debate often wins the day, even if the science isn’t there to support it,” says Dr. Gaynor Watson-Creed, the medical officer of health for the Capital District Health Authority and IWK Health Centre. “It’s very difficult to look a very passionate advocate in the eye and refute their claims.”
Public-health authorities and the scientific community have also done a poor job of communicating why fluoride is beneficial. Fluoridation has been called “one of the 10 great public health achievements of the 20th century” by the American Centers for Disease Control and Prevention.
Fluoridation is currently backed by over 90 national and international professional health organizations. “Generally, every major health organization in North America and worldwide… are all unanimous in the fact fluoride is beneficial at the doses Health Canada is recommending,” says Alisha Knowles, Halifax Water’s water quality manager. “So, who else would you believe as an authority?”
For anti-fluoride activists, the answer is typically information sourced from the Internet. Entering the term fluoride into a search engine will mostly yield results for anti-fluoridation websites.
While the fluoride debate tends to get simplified as being about cavities, there is a strong link between dental health and overall health. This is something Watson-Creed saw in her previous career as a family doctor. “I had the misfortune of seeing people who had dental decay which led to serious abscesses in different parts of the body,” she says, singling out the throat, brain and heart. Because of the anatomy of the body, organisms that live in the mouth have fairly direct access to other parts of the body. “It all started from bad teeth,” says Watson-Creed. “We forget that tooth decay can have some pretty serious, life-threatening consequences if it’s not dealt with.”
Bad teeth cause pain, which makes kids not want to eat, says Watson-Creed. Malnutrition can be a consequence of tooth decay in children.
While many toothpastes and mouthwashes contain fluoride, they are not ingested, but instead applied topically. It’s the same for fluoride treatments at the dentist. So why do people need fluoride from the water supply when they can just get it from topical applications? “Fluoride that is ingested in water in small amounts actually impacts on the way those teeth develop right from day one,” says Watson-Creed. When fluoridated-water is ingested it strengthens enamel and works its way into the salivary tissues and provides a far more constant presence in the body.
The question of ingestion vs. topical application preoccupies the anti-fluoride movement. “It says, ‘Do not swallow,’ but they’ll pour it in your drinking water,” says Dana Landry, the founding member of Safe Water Halifax. Landry wonders why toothpaste shouldn’t be swallowed, but it’s OK to drink fluoridated water. The reason is because toothpaste contains a much higher concentration of fluoride than tap water does. Landry disputes that. “It’s the same,” she says.
Fluoride consumed from drinking water typically has a concentration of around .7 parts per million (PPM), while topical fluorides have a concentration ranging between 1,000 and 22,000 PPM, says a University of Toronto Faculty of Dentistry document on water fluoridation.
Health Canada recommends workers fluoridate tap water at a maximum of 1.5 PPM. “Water containing fluoride at, or below, this maximum acceptable concentration does not pose a risk to human health,” says Health Canada’s website. Halifax Water’s objective is to fluoridate at a rate between .7 and .8 PPM.
A report from the Nova Scotia Dental Association praises that decision, saying it benefits people “regardless of age, oral health habits, socio-economic status, or life circumstances,” says a Nova Scotia Dental Association document. Presently, the cost of Halifax Water doing this is about $120,000 per year, which works out to about $1.50 per household.
There is Canadian data comparing tooth-decay rates in fluoridated vs. non-fluoridated communities. A study in B.C. looking at six to 14-year-old children who lived in the fluoridated city of Kelowna found the children “had 35 per cent fewer decayed or filled tooth surfaces than similar children” in the non-fluoridated city of Vernon. (The two communities are about 50 kilometres apart.)
The anti-fluoride movement and Landry call fluoridating water a form of mass medication, but fluoride is a naturally occurring mineral and it is found in soil, air, plants, animals and water supplies. When talking with Halifax Magazine, Landry called fluoride a “toxin” and “poison.” A 70-kilogram adult would need to drink 15,000 litres of fluoridated water with a concentration of .7 PPM in one sitting to consume a lethal toxic dose, says the University of Toronto document.
It is important to note when organizations such as Health Canada make their determinations about whether water fluoridation is safe, they are taking into account all available scientific literature. With that in mind, the consensus is water fluoridation is a safe and effective. “Public health around the world is constantly monitoring this and of course, if the science shifted around this, we would shift as well,” says Watson-Creed. “But the science has not shifted for close to 50 years.”
CORRECTION: An earlier version of this story misstated Health Canada’s recommendation for the concentration of fluoride in drinking water. The text above has been corrected.