Deciding whether to add fluoride to town water supplies is a vexed issue for local decision makers, Tauranga mayor Stuart Crosby says.

“You can get 10 expert reports that say fluoride is safe and is good for people and you can get another 10 expert reports that say it’s unsafe and we shouldn’t use it.”

The Government is being urged to give district health boards the final say on putting fluoride in town water supplies.

An inquiry by the parliamentary health committee on child health, released on Monday, recommended the Government invest in a nationwide oral health campaign, and transfer responsibility of water fluoridation from local councils to the Ministry of Health.

DHBs would decide standards on the “optimal level of fluoridation” in local water supplies, and work together with local councils to put the standards in place.

At present, councils vote on whether to add fluoride to the water, and how much to add.

Fluoride was taken out of Tauranga’s water supply in 1992 after a referendum where more than half of the city’s residents voted against its continued use.

Mr Crosby said he would be concerned if Bay of Plenty District Health was able to make that decision.

The supply of water was a local authority service and the accountability and responsibility for what went into it started and finished with the local authority, he said.

“If you had another entity putting a substance in, I would ask the question, ‘where does the liability lie?’

“From my experience, the Ministry of Health in particular and previous ministers of health have wanted councils to put in fluoride but will not take the responsibility.

“That’s a cop out.”

Communities nationwide remain bitterly divided on whether to add fluoride to town drinking water supplies.

Hamilton residents voted overwhelmingly to retain fluoride last month after a heated debate saw the council remove it in July.

In Hastings, a fluoride referendum was held alongside council elections last month. Residents voted to retain water fluoridation.

Anti-fluoridation group Fluoride Action Network New Zealand has argued fluoride can be linked to adverse health effects such as arthritis, thyroid dysfunction, lowered IQ and hypersensitivity.

However, the parliamentary health committee’s report said scientific evidence was clear that adding fluoride to a town water supply in appropriate monitored doses led to a reduction of dental decay in children, particularly children living in low socioeconomic families.

It recommended health experts produce and monitor “strong scientific evidence” to back up their decisions on adding fluoride to water.

However, Health Minister Tony Ryall said fluoridation of public water supplies was a decision for local communities.

“The Government’s role is to support local councils when they decide to use fluoride – not to make the decision for them, and we are not considering changing that.”

Local Government New Zealand president Lawrence Yule said it would be a “huge shift” to give DHBs the power to fluoridate water supplies – though DHBs would still be accountable to voters.

“I think it probably sits better there than it does with the [councils], we have no experience about the health risks so I would probably welcome that overall.”