What you need to know about fluoride

Hot on the heels of recent news that another city -- Saint John, N.B. -- will stop adding fluoride to its drinking water, here’s what you need to know about the practice.

What is it?

Fluoride is a mineral that’s often added to drinking water and toothpaste in order to help prevent tooth decay.

Why is it in drinking water?

Cities began fluoridating their water supplies after it was found that those drinking from a naturally fluoridated water supply had significantly fewer cavities than those drinking unfluoridated water.

Major dental associations and even the World Health Organization support the fluoridation of drinking water because of its ability to prevent tooth decay.

Also see: Most people aren't brushing properly

Who else has banned it?

Here’s a list of other Canadian cities that have banned the use of fluoride in drinking water, as reported by PostMedia.

• Lasalle, Ontario – January 29, 2013

• Windsor, Ontario – January 29, 2013

• Bécancour, Quebec – January 16, 2013

• Okotoks, Alberta – December 20, 2012

• Kirkland Lake, Ontario – December 18, 2012

• Rosetown, Saskatchewan – July 16, 2012

• Orillia, Ontario – July 16, 2012

• Tecumseh, Ontario – March 13, 2012

• Wynyard, Saskatchewan – March 1, 2012

• Amherstburg, Ontario – February 6, 2012

• Moncton, New Brunswick – December 19, 2011

• Dieppe, New Brunswick – December 12, 2011

• Lake Cowichan, British Columbia – November 19, 2011

• Williams Lake, British Columbia – November 19, 2011

• Lakeshore, Ontario – October 31, 2011

• Churchill, Manitoba – October 16, 2011

• Slave Lake, Alberta – September 12, 2011

• Taber, Alberta – July 20, 2011

• Meadow Lake, Saskatchewan – July 4, 2011

• Flin Flon, Manitoba – July 2011

• Calgary, Alberta – February 8, 2011

• Vercheres, Quebec – February 7, 2011

• Athabaska, Alberta – November 1, 2010

• Waterloo, St. Jacobs, Elmira, Ontario – October 25, 2010

• Gatineau, Quebec – May 4, 2010

• Thunder Bay, Ontario – July 21, 2009

• Cranberry Portage, Manitoba – January 1, 2009

• Drayton Valley, Alberta – December 31, 2008

• Kingston, Ontario (Canadian Forces Base) – May 2008

• Dryden, Ontario – April 2008

• Quebec City, Quebec – April 1, 2008

• Region of Niagara, Ontario – January 24, 2008

• Kamsack, Saskatchewan – 2008

• Langham, Saskatchewan – 2007

• Golden, British Columbia – November 19, 2005

• Foam Lake, Saskatchewan – 2005

• Burns Lake, British Columbia – June 25, 2003

• Dutton-Dunwich, Ontario – June 2003

• West Elgin, Ontario – June 2003

• Preeceville, Saskatchewan – 2003

• Rosthern, Saskatchewan – 2003

• Cobalt, Ontario – December 11, 2001

• Kamloops, British Columbia – October 13, 2001

• Whitehorse, Yukon – July 28, 1998

• Kitimat, British Columbia – March 1998

• Kelowna, British Columbia – November 16, 1996

• Campbell River, British Columbia – April 1993

• Port Hardy, British Columbia – November 1993

• Squamish, British Columbia – November 1993

• Comox-Courtenay, British Columbia – February 1992

• Vancouver, British Columbia – early 1960′s

Also see: All the seeds you should be eating

Why is it a concern?

“The most common problem with excess fluoride levels is fluorosis, which can cause teeth to be stained brown and to crack or pit,” Yahoo Canada News reported.

“But most of the concern is with levels many times higher than the trace amounts put into drinking water.”

The United States Center for Disease Control notes that most instances of fluorosis are so minor that only a dental professional would notice, and severe cases that result in pitting are very rare. Children are most at risk for fluorosis.