Opponents of adding fluoride to Juneau’s water supply ramped up their offensive last week, bringing in a national expert to lecture Thursday and Friday nights to drive home their point that fluoride is dangerous to the human body.

Hardy Limeback sat on the 12-member National Research Council that looked into the toxic effects of fluoride in drinking water. The panel, which is part of the National Academy of Science, reviewed hundreds of peer-reviewed, published studies on the harmful effects of fluoride on the body.

Limeback is a dentist and associate professor at the University of Toronto, where he chairs the Preventive Dentistry Department. He has a doctoral degree in biochemistry.

“There’s a groundswell of scientists who are opposed to putting this in the water,” Limeback said. “There’s so much new science out there that should be weighed, versus the so-called benefits, which have declined.”

George Brown, a pediatrician, was one of a few doctors who attended the lecture. Brown said Limeback’s research is valuable, but he is still in favor of resuming fluoridation until the community has another way of assuring effective preventive dental care for children whose families cannot afford it.

“(Limeback) is very knowledgeable. He is a research scientist and he’s raising a lot of issues that are important. I listened, I learned something, I respect the man and I respect the viewpoint,” Brown said. “I’m coming from the point of view that to say no fluoride is necessary is just as extreme as to say it’s not toxic at all, and more research needs to be done.”

The maximum amount of fluoride allowed in drinking water is 4 milligrams per liter, a standard set by the Environmental Protection Agency in 1986. At levels higher than that, water is considered contaminated. Where fluoride is added to water, it is usually at .7 to 1.2 milligrams per liter. Fluoride also occurs naturally in many water supplies.

Limeback said that since fluoride accumulates in the body, it’s not the concentration that is important. It’s the overall dosage, or the overall amount that people swallow, that matters.

So while the mainstream medical establishment still believes there is a safe concentration that can be achieved in drinking water, Limeback said those who drink it continually may build up toxic levels in their bodies. He does believe fluoride is beneficial if it is used directly on teeth, like it is with toothpaste.

Carolyn Brown, an obstetrician and chairwoman of the pro-fluoridation group Citizens for Dental Health, said the bottom line is that fluoridation provides public health benefits.

“The preponderance of evidence supports having fluoride in the water as a benefit to public health. For those few people who simply cannot abide having fluoridation in their water, there are any number of (water filtration) systems that are available that will take it out,” said Carolyn Brown, who is married to George Brown.

Limeback was originally invited to Juneau to give a continuing education lecture to Bartlett Memorial Hospital staff. Bartlett’s continuing education committee did not accept him, so arrangements were made to lecture to the general public.

He said he was disappointed that most of the medical profession in Juneau did not come to the lectures, and that critics who call his point of view “junk science” are “terribly ignorant.”

Most dental programs in America do not have a course on fluoride toxicity, he said, so most dentists do not know its harmful effects on the body.