Fluoridating Christchurch’s water supply would be unethical, and a form of mass medication, the Green Party says.

The Greens health spokeswoman, Sue Kedgley, said yesterday a worldwide trend existed away from fluoride in water, and the Canterbury District Health Board (CDHB) was pursuing the “wrong demon” if they thought fluoridating Christchurch’s water was the way to reduce tooth decay.

The Swiss city of Basel last month voted to remove fluoride from its water supply after 41 years.

Tooth decay had doubled in Basel’s children since 1996, and no evidence existed to show Basel had lower rates of tooth decay than other Swiss cities, she said.

The major cause of dental cavities among children was poor dental hygiene, and the consumption of excessive amounts of sugar in drinks and food, Ms Kedgley said.

“Instead of spending $3 million on fluoridating the Christchurch water supply, the CDHB should fund a public health education campaign about dental hygiene,” she said.

Unanswered questions remained about the effectiveness of fluoridation, and possible adverse effects from long-term consumption of fluoride in water, Ms Kedgley said.

She also questioned the ethics of what was effectively a form of “mass medication.”

School and Community dental health service head Martin Lee said the mass medication argument was nothing new.

“That is the spin they (anti-fluoride lobbyists) put on it,” he said. “It (fluoride) reflects a natural phenomenon. In other parts of the world it is in the water naturally.”

Water was fluoridated in South Africa, and in 75 per cent of Ireland’s water supply, Mr Lee said. It was also expanding in the United States. In California, water supply companies abided by mandates which said they had to put fluoride in the water, he said.

“As for the CDHB funding a publicity campaign, what are they going to fund it with?” he said. “In Christchurch, the CDHB is paying more (dental costs) because we don’t have fluoride in the water.”

It was not hard to find information supporting either side of the fluoride argument, Mr Lee said. “It is really easy to pluck out isolated studies that support your point of view, with no great scientific fact.

“Just like with vaccination. But what happens when you take all of the evidence and weigh it up?” he said. “On balance, it shows that fluoride reduces tooth decay.”

Christchurch Hospital dental service clinical director Gordon Carter said fluoride was a human rights issue, because people were forced to take it if it was in their water supply.

“But at the end of the day, it is still a public health measure,” he said. “It is only going to reduce dental disease.”