A move to add fluoride to most of Sonoma County's drinking water to improve dental health received a significant boost Tuesday from the Board of Supervisors.
The board's unanimous decision backing further study of a practice common across the country and recommended by leading national and international health agencies still provoked emotional protests from some speakers.
They proclaimed fluoride a health danger and decried government tinkering with the water supply, comments that drew unusually sharp rebukes from two supervisors.
"While I respect everyone's right to free speech, the hyperbole shared today was off the charts. Off the charts," Supervisor Mike McGuire said.
His response came after several speakers alluded to fluoride's addition to water systems in Europe last century, a move that one speaker said was used for "mass mind control" by totalitarian regimes in Germany and the Soviet Union.
Another called fluoride a "witches' brew of pollutants" in the U.S. water system.
"You don't improve the health of children by giving them poison," said Deborah Tavares, a frequent board critic active in property rights issues.
McGuire called the claims "scare tactics" and the theories "an absolute insult" to a proposed initiative aimed at combating an epidemic of dental decay.
Supervisor David Rabbitt linked the comments to arguments put forward by opponents of vaccines.
"Vaccines, fluoride. They're not poison," he said. "I sit up here and I'm bewildered because as a society we're now living longer than ever, thanks to those vaccines, thanks to fluoride for our teeth. That's a fact."