Children living in parts of northern NSW without fluoridation already have the worst teeth in the state. They have nearly double the number of decayed, missing and filled teeth compared with other children, according to the most recent dental health survey.

This is what happens when you give control of fluoridation to local councils.

The state’s chief medical officer, Dr Kerry Chant, travelled to Ballina this week to persuade counsellors to vote against the motion, arguing there was no scientific or health evidence to show fluoride had negative effects on health.

A decision not to proceed with water fluoridation would deny generations of Ballina residents what the survey described as one of the “most effective and socially equitable means of preventing tooth decay”.

Some anti-fluoride activists, such as Merilyn Haines, the president of Queenslanders for Safe Water Air and Food, argue that fluoride is a poison that is used as an insectide to kill roaches and ants.

But Ballina Council member Keith Williams, who proposed the motion, said he saw it as a human rights issue.

“I don’t dispute the scientific evidence of dentistry that it prevents cavities, but I don’t believe it is appropriate to add a medication to the water supply without everybody’s consent.”

He said at least one-third of residents were opposed to fluoridation. “I think they have a right to clean, safe water that doesn’t have it,” he said.

About 96 per cent of NSW has access to fluoridated water. For the past 10 years, anti-fluoride activists have used legal action to delay the introduction of fluoride in northern NSW by public utility Rous Water.

Rous services the northern NSW councils Lismore, Ballina, Byron Bay and the Richmond Valley. Byron Bay voted in 2007 not to add fluoride. In the past few years, it is estimated that the three other councils with NSW Health have spent nearly $500,000 fighting the legal action. They won on appeal, only to see Lismore nevertheless vote not to proceed.

Anti-fluoridation action has been spreading from Queensland south into NSW. Since Queensland Premier Campbell Newman’s government overturned the previous government’s decision to make fluoridation of the water supply compulsory, 17 councils, including Mt Isa and Rockhampton, have voted to either stop adding fluoride or have stopped moves to build fluoridation plants.

The federal opposition’s health spokesman, Dr Andrew McDonald, told ABC that the Lismore decision was “complete madness”.

Members of both parties have called on the NSW government to make fluoridation compulsory. Currently, it is up to each council to decide, and then seek approval for its decision, or ask NSW Health to decide for it.

Dr McDonald called on the government to step in and take control of fluoridation.

“This is what happens when you give control of fluoridation to local councils,” he said.

Catherine Cusask, a Liberal MP who lives at Lennox Head on the north coast, has also been campaigning for the government to intervene. She urged NSW Health Minister Jillian Skinner to intervene.

“It is not just the right and decent thing to do – the message we send, by leaving Rous and Ballina in the lurch, is a huge setback and a disincentive to any other council considering fluoridation.

“It is time for NSW Health to get off the sidelines, to put its own skin in the game, and to assume control of fluoridation, as recommended in 2006.”

The general manager of Rous Water, Kym Lavelle, admitted Lismore Council’s decision surprised him, given the resources committed to the building the new water treatment plants.

Some anti-fluoride activists argue that fluoridated toothpaste has removed the need for fluoridation of the water supply. But Dr Chant said research showed that fluoridation accounted for about 70 per cent of the decline in tooth decay, while fluoridated toothpaste had contributed about 25 per cent to the improvement.