Fluoride levels in some New Zealand districts are too high for bottle-fed babies, according to figures from the European Commission.

Infants’ milk formula should not be mixed with water fluoridated at a level higher than 0.8 milligrams per litre of water, the commission’s scientific committee on health and environmental risks said.

Its report said over-exposure to fluoride could lead to mottled teeth. However, claims that it could also lead to diseases such as cancer “cannot be substantiated”.

Fluoride levels in the drinking water of six lower North Island councils ranged from 0.7 and 1.0 mg/l – the guidelines recommended by the Health Ministry.

New Zealand’s drinking water standards allow a maximum of 1.5 mg/l.

Not only babies were at risk of tooth damage, the commission found. Its “pre-consultation opinion” said drinking more than half a litre of fluoridated water a day and swallowing too much fluoride toothpaste could harm children up to age six.

Yesterday, Fluoride Action Network’s Mark Atkin said anti-fluoride campaigners were partly vindicated by the report, which was published on Wednesday.

“But any level of [introduced] fluoride at this age is too much. Babies at six months drink a lot of liquid for their body weight, and they’re getting 100 to 250 times the naturally occurring [fluoride]. We hope the Ministry of Health will now stop denying the importance of this warning.”

Ministry acting chief dental officer Tim Mackay was confident “baby formula made from fluoridated water is safe for consumption” by New Zealand infants. The ministry did not consider it necessary to change the levels.

Hastings District Council is the latest local body to decide to continue with a fluoride programme to prevent tooth decay. It decided on Thursday, by seven votes to six, not to hold a public referendum on the matter.

It would continue to dose the city’s water supply with fluoride but would look at lowering the current 0.9mg/l level to 0.7 in the wake of the European Commission report.

Last week, Kapiti Coast District Council navigated its way through an emotional fluoride debate, which included councillors accusing anti-fluoride campaigners of intimidation. It voted to continue putting the chemical in its drinking water.

The commission’s report said putting fluoride directly onto teeth was the best way to prevent tooth decay.

“In children, a very narrow margin exists between achieving the maximum beneficial effects of fluoride in caries [decay] prevention and the adverse effects of dental fluorosis.”

Fluoride levels measured in milligrams per litre of water:

Kapiti: 1.0
Hastings: 0.9
Wellington City: 0.8
Porirua: 0.8
Hutt Valley: 0.8
New Plymouth: 0.7
Palmerston North: 0.7 to 1.0