JOSHUA ALLAN
The 1510 West

Adding fluoride to drinking water supplies  was first studied in Canada in 1947. The federal Department of National Health and Welfare launched a seven-year study on the effects of adding small amounts of fluoride to the drinking water supply of the town of Brantford, Ont., specifically with regards to the dental health of children.

By 1955, research results indicated that resistance to tooth decay and overall tooth health among children in Brantford had become far higher than that of children in the nearby town of Sarnia, whose water supply was not fluoridated.

The federal government began recommending the fluoridation of drinking water supplies to the provinces in 1968 at a target of 1.2 milligrams of fluoride per litre of water. This target was lowered to 1 milligram in the 1970s, and again to 0.7 milligrams by 2008, the amount still recommended by Health Canada today.

The most common side effect of the consumption of fluoridated water listed by Health Canada is dental fluorosis, resulting in small, often unnoticeable white spots on permanent teeth. Dental fluorosis can only develop as children’s permanent teeth are budding and is found in about 16 per cent of all children who consume fluoridated water.

A 2023 report by the U.S. National Institutes of Health National Toxicology Program indicates that children consuming over 1.5 milligrams of fluoride per litre of water showed signs of scoring lower on IQ tests than other children. However, a panel of experts commissioned by Health Canada found that there is not enough evidence to determine that smaller amounts of fluoridated water (0.7 milligrams/litre) had any negative neurocognitive effects on children.

Today, some 14 million Canadians access fluoridated drinking water. The provinces with the highest proportion of fluoridated water systems are Ontario (73%), Manitoba (68%) and Nova Scotia (50%).

In Quebec, however, just 1 per cent of water systems are fluoridated, a figure that will drop after the Pointe Claire and Dorval water treatment plants stop fluoridating by next year. St. Georges in the Beauce region will become the last municipality in the province that fluoridates its water supply.