Fluoride

Most water supplies contain some fluoride and in the early 20th century, levels of tooth decay were found to be associated with fluoride levels in drinking water.

This led to the introduction of water fluoridation schemes to add fluoride to water supplies to improve dental health.

Community water fluoridation schemes have operated for over 70 years; the first fluoridation scheme was introduced in the US in 1945. The first substantive UK scheme was established in Birmingham in 1964.

Community water fluoridationin England

Around 5.8 million people in England receive fluoridated water. This means fluoride has been added to bring it up to around 1mg of fluoride per litre of water, which is a level found to reduce tooth decay levels.

The decision about whether to add fluoride to the water supply is made by individual local authorities. Areas where water fluoridation schemes are currently in place include parts of:

• the West Midlands
• the North East
• the East Midlands
• Eastern England
• the North West
• Yorkshire and Humber

In some parts of the country, such as parts of the North East and Midlands, the public water supply naturally contains a level of fluoride that's similar to that seen in schemes. Some private water supplies contain more than this amount.

Your local water supplier should be able to tell you how much fluoride is in your water supply and whether any is added.Most companies have an online facility where you can use your postcode to check the water in your area.

What research has been carried out?

Over the past 50 years, there have been several reviews of the safety and effectiveness of water fluoridation schemes. Recent largereviews that have been carried out include:

• Public Health England: Water fluoridation health monitoring report for England(PDF, 1.51Mb)in 2014 (read theNHS Choices coverage of this report)
• NHS Centre for Reviews and Dissemination: A systematic review of water fluoridation (PDF, 6.22Mb)in 2000
• Centers for Disease Control and Prevention (US): Recommendations on selected interventions to prevent dental caries, oral and pharyngeal cancers and sports-related craniofacial injuries (PDF, 69kb) in 2002
• National Health and Medical Research Council (Australian Government): Efficacy and safety of fluoridation in 2007
• US Department of Health and Human Services Community Preventive Services Task Force: Community water fluoridation in 2013
• Royal Society of New Zealand: Health effects of water fluoridation (PDF, 1Mb) in 2014
• Health Research Board (Ireland): Health effects of water fluoridation (PDF, 1.58Mb) in 2015
• Cochrane Oral Health Group: Water fluoridation for the prevention of dental caries in 2015

Overall, these reviews found that water fluoridation appears to contribute to reduced tooth decay levels anddoesn't seem to be associated with any significant health risks (see below).