ALMOST half a million people in regional Victoria, including residents of Geelong and Ballarat, will have fluoride added to their tap water by the end of next year.

The move by the Brumby Government follows a report that found extending the fluoridation of drinking water across regional towns would deliver a financial benefit of more than $220 million over 25 years.

The Age believes the $1 million plan — which would boost the proportion of Victorians with fluoridated water to about 85% — will be announced today.

The Government has placed advertisements in Geelong and Ballarat newspapers today, notifying residents of the plan after consultation with local communities.

The move will, in effect, bring forward fluoridation for Geelong, which will be connected to Melbourne’s fluoridated water system by 2011 anyway.

According to the Department of Human Services, six-year-old children in fluoridated water areas experience up to 36% less tooth decay than those in non-fluoridated areas.

Fluoride is a naturally occurring compound that helps stabilise the mineral content of bones and teeth and helps prevent tooth decay.

Melbourne has had fluoridated water for more than 30 years, but most of regional Victoria does not — with the exception of some towns including Bendigo and Shepparton.

Opponents, who are particularly active in Geelong, argue that fluoridation amounts to medicating people without their consent. Some argue fluoride is a poison that can damage the human nervous system.

Democratic Labor Party MP Peter Kavanagh said there was considerable evidence that fluoridation could be harmful — with possible effects including decreased IQ and osteosarcoma in young males — while it had minimal impact on preventing tooth decay. “If you are going to put a chemical in the water supply, you really have the obligation to show it is going to be beneficial and not harmful,” Mr Kavanagh said.

Victorian Nationals leader Peter Ryan said the fluoridation of Geelong and Ballarat water was decision-making by stealth, even though there was a majority view supporting it. “There are very, very strong views about it in some communities and people are entitled to have a point of view over this issue,” he said.

The report, conducted for the Department of Human Services and obtained by The Age under freedom of information, calculated that, for a cost of $51 million, fluoridation has produced a financial benefit of $646 million over 25 years — mainly from reduced dental care costs and fewer working hours lost due to dental problems.

“The analysis therefore shows that there would be clear net benefits associated with an extension of water fluoridation to a wide range of rural and regional water supplies in Victoria,” the report said.

It also discounted claims of negative health effects such as acute toxicity, dental and skeletal fluorosis, and bone fracture and mineral density problems. “A recent study of these issues, involving a review of published literature, found little evidence to support claims of negative health impacts in the majority of these areas,” the report said.