Fluoride

Fluoride is a mineral salt that can be present in the environment. It is most often found naturally in soil and can dissolve in groundwater. Water is not the only source of fluoride. It can also be found in:

• Food, such as marine fish, and beverages, such as tea
• Some dental hygiene products such as toothpastes and mouthwashes

A small amount of fluoride in drinking water has beneficial effects. By helping with the mineralization of teeth, fluoride protects against dental cavities. To learn more, read Fluoridation of drinking water.

By Québec standards, the concentration of fluoride in drinking water must not exceed 1.5 mg/L.

Prolonged consumption of water containing more than 1.5 mg/L of fluoride can cause dental fluorosis in children under nine years old. Dental fluorosis appears as permanent white or brown stains on the teeth during their development.

Consumption of water containing fluoride concentrations exceeding 4 mg/L could cause a risk of skeletal fluorosis in people who consume it over many years. Skeletal fluorosis makes bones more fragile and can cause pain and stiffness in the joints.

Some studies have found possible health effects when fluoride levels in water are higher than 1.5 mg/L. However, there are still uncertainties and more research is needed.

Your water should be tested for fluoride at least once during the period of usage of the well.

If the concentration of fluoride in your well water exceeds 1.5 mg/L, it is recommended to use another reliable source of water to:

• Give children under nine years old a drink
• Make beverages, including infant formula

If the concentration of fluoride in your well exceeds 4 mg/L, all family members should use another source of water for drinking and preparing beverages.

You can still use well water to:

• Wash food
• Steam food
• Wash dishes and clothes
• Take a shower or bath

If your water has a high concentration of fluoride, tell your doctor and your dentist.

Boiling water to eliminate fluoride is pointless because it does not evaporate. Doing so can even increase the concentration of fluoride in the water.

You can install a residential water treatment system to reduce the concentration of fluoride in water to an acceptable level. Be sure to install a certified system conforming to NSF/ANSI standards and follow the manufacturer's maintenance recommendations.