Water fluoridation safe, with dental benefits

IN HIS commentary ("The case against fluorides in water"; 18 August 2012), Dr Andy Ho observed concerns arising from the release of a recent study on the impact of high fluoride exposure on children.

He described water fluoridation as a "mandated ingestation of fluoride via public water usage".

In fact, fluoride is a natural element that is already present in various forms around us, such as in the air, our food and water, but in insufficient amounts to have any dental benefits.

Research by the World Health Organisation (WHO) has shown that fluoride is most effective in preventing dental caries if a low level of fluoride is constantly present in the mouth.

In 1954, Singapore adopted fluoridation after a careful review of the benefits, effectiveness and safety of fluoridation.

Since then, the rate of dental decay decreased by 30 per cent among children, and has contributed to Singapore having one of the lowest levels of tooth decay for 12-year-olds in the world.

Current levels of fluoride in our water system are low, safe and constantly monitored.

We have progressively reduced our fluoridation level over the years to factor in fluoride intake from other sources, from a concentration level of 0.7mg/l to 0.5mg/l in our tap water currently.

This is well within WHO's recommended maximum concentration of 1.5mg/l - a value first set in 1984, and which has remained unchanged after the latest review in 2008.

In the recent study quoted by Dr Ho, the fluoride levels in drinking water (typically from wells or springs) in "high exposure" groups were generally many times that in our water system.

He also contended that water fluoridation may no longer be necessary, given better oral hygiene today.

While Singaporeans today have greater access to more sources of fluoride such as fluoride toothpastes and mouth rinses, these products are not used optimally by everyone.

Water fluoridation thus remains one of the most cost-effective preventive public health measures for tooth decay for Singaporeans.

Our experts in the Fluoride Review Committee meet regularly to review the appropriate and safe concentration level of fluoride in our water supply, and have recommended that we should continue with water fluoridation.

Associate Professor Patrick Tseng
Chief Dental Officer
Ministry of Health