Pressure that led to drinking water review is unlikely to ease

Analysis: Lack of definitive evidence means some will continue to call for change

The addition of fluoride to drinking water supplies is an issue that arouses passionate opposition among a vocal minority and some befuddlement in the rest of the population.

A determined grassroots campaign has succeeded in getting at least five councils to pass motions calling for an end to fluoridation, notwithstanding the benefits it brings for dental health. The issue is raised regularly in the Oireachtas – more than 50 times since the start of last year – where independent Senator Mary Ann O’Brien last year proposed a motion to achieve this objective.

Ms O’Brien, who makes chocolates for a living, claims fluoride is a “highly poisonous substance” (in fact, everything is poisonous, depending on the dose) and points out that most other European countries have moved away from mass fluoridation.

Labour TD Emmet Stagg and Minister for Agriculture Simon Coveney are other fluoridation sceptics.

READ MORE

Partly as a result of this pressure, the Department of Health last year commissioned a review of the health effects of the practice. The Health Research Board was asked to look at the effects of adding fluoride at concentrations of between 0.4 and 1.5 milligrams per litre (mg/l).

Irish water

The compound has been added to Irish water supplies at a rate of 0.6-0.8mg/l since 2007. Before then, the rate used was 1ppm.

So is the addition of fluoride to our drinking water safe?

Unfortunately, this review of previous studies does not give us clear-cut answers in respect of many of the claimed negative health effects of fluoridation and so anyone seeking certainty is doomed to disappointment. At its most unambiguous, it says there is no definitive evidence of claimed harmful effects such as bone fractures, reduced IQ or Down syndrome.

In relation to a small number of studies that have suggested links between fluoridation and bone cancer or thyroid disease, it is sceptical about the scale of research involved and the existence of a causal relationship, and says more research is needed.

Health problems

A number of health problems arise where the intake of fluoride is high ie above 1.5mg/l, due to natural occurrence of the compound. However, this does not arise anywhere in Ireland so it should not be a concern here.

In summary, therefore, the board’s findings give no new cause for concern about current practice, but neither are they likely to stifle calls for a change in policy.

Paul Cullen

Paul Cullen

Paul Cullen is Health Editor of The Irish Times