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Water Fluoridation



Fluoride is a naturally occurring mineral which is present in virtually all water sources. The City of London receives water from Lakes Huron and Erie, which have relatively low fluoride levels. In the early part of the 20th century, it was observed that communities with low natural fluoride levels in their water experienced higher rates of tooth decay. Subsequent research confirmed the important role that fluoride plays in preventative oral health.

Fluoridation of drinking water is now practiced by water systems worldwide. The process consists of the controlled addition of fluoride to water with naturally low fluoride levels, thereby raising the fluoride content to an optimal level for the promotion of dental health.

According to the World Health Organization (WHO), “There is clear evidence that long-term exposure to an optimal level of fluoride results in diminishing levels of caries in both child and adult populations.”

“Research has shown that fluoride is most effective in dental caries prevention when a low level of fluoride is constantly maintained in the oral cavity. The goal of community-based public health programmes, therefore, should be to implement the most appropriate means of maintaining a constant low level of fluoride in as many mouths as possible.”

The U.S. Centers for Disease Control and Prevention (CDC) recognized the fluoridation of water supplies as one of the 10 most important public health achievements in the 20th century, and more than 90 national and international public health agencies have endorsed the use of fluoride at recommended levels to prevent tooth decay, including Health Canada, the U.S. Surgeon General, the Canadian Dental Association, the American Dental Association and Ontario’s Chief Medical Officer of Health.

However, there is opposition to water fluoridation, with concerns that adverse health effects may be the result. In 2011, Health Canada released the results of a multi-year, systematic review of the health risks associated with fluoride in drinking water and concluded that “The weight of evidence from all currently available studies does not support a link between exposure to fluoride in drinking water at 1.5 mg/L and any adverse health effects”. Health Canada also concluded that “… the optimal concentration of fluoride in drinking water for dental health has been determined to be 0.7 mg/L for communities who wish to fluoridate”.

The City of London started adding fluoride to its drinking water in 1967, after it was approved by a public plebiscite in 1966. In 2012, London’s City Council reviewed its fluoridation policy, which included a public participation meeting where all concerned parties were given the opportunity to provide information to Council. After reviewing the information provided, Council voted to support the ongoing fluoridation of the City of London’s drinking water.