MELISSA BLOCK, HOST:
You're listening to ALL THINGS CONSIDERED from NPR News.
Portland, Oregon, has long prided itself on its pure water, free of fluoride. And there's a strong environmental ethic in Portland as well. So when plans emerged to fluoridate the water, the city lit up. And today, over the jeers and cheers of dozens of residents, commissioners voted unanimously to add fluoride.
We have more on the science behind the issue and the debate in Portland from Kristian Foden-Vencil of Oregon Public Broadcasting.
KRISTIAN FODEN-VENCIL, BYLINE: Last century, scientists in Colorado Springs found high levels of naturally occurring fluoride. They also noticed many local children had mottled or brown teeth, but that their teeth were surprisingly resistant to decay. So in 1945, Grand Rapids, Michigan, agreed to an experiment adding small amounts of fluoride to its water. An 11-year study by the U.S. Surgeon General found the rate of cavities among children there dropped 60 percent. But not everyone's convinced.
KIM KAMINSKI: We know that it affects the thyroid gland. We know that it affects insulin secretion. We know that it affects children's IQ levels.
FODEN-VENCIL: Kim Kaminski is battling the introduction of fluoride in Portland's water. She cites many studies to support her cause. Perhaps the most worrisome hit the news in 2006 out of Harvard.
(SOUNDBITE OF ARCHIVED BROADCASTS)
UNIDENTIFIED MAN #1: Could fluoridated water cause cancer?
UNIDENTIFIED MAN #2: We may have a problem with fluoridation in drinking water.
UNIDENTIFIED MAN #3: New research shows...
FODEN-VENCIL: The study found that for boys under 20, fluoride levels in drinking water were associated with an increased risk of osteosarcoma, a bone cancer. Kim Kaminski says that's scary.
KAMINSKI: This was peer reviewed and published, and it's a very solid study. And at the time, being a mom, it was very concerning to me.
FODEN-VENCIL: An adviser to that study was Dr. Catherine Hayes of Health Resources in Action. She was also the co-author of the follow-up study. She says instead of gathering information about previous cases of osteosarcoma, as was done in the first study, they looked at actual samples of bone from people who had the cancer. And, she says, as far as she's concerned, there's no link.
DR. CATHERINE HAYES: In that study, the bone was carefully examined amongst individuals who had the osteosarcoma and those that did not, and there was no difference in the amount of fluoride in the bone. And that's really significant, because now we're not estimating fluoride intake, we're really measuring it.
FODEN-VENCIL: Still, anti-fluoride activists like Kim Kaminski remain unconvinced. They say the co-author, Chester Douglass, received payments from a toothpaste company. Hayes dismisses that concern.
HAYES: He was thoroughly investigated by Harvard University and found completely innocent of any wrongdoing.
FODEN-VENCIL: Portland City Commissioner Randy Leonard has looked at many studies, including the one out of Harvard, and says he's going to go along with the Centers for Disease Control and Prevention and the many other public health agencies that endorse fluoridation.
RANDY LEONARD: It is time for Portland to join every other large city in the United States. And the people that suffer the most from not having fluoridated systems are kids and particularly kids of color, and it has to stop.
FODEN-VENCIL: Still, city commissioners won't have the last say here. Anti-fluoride advocates already have a ballot measure to put to the people. For NPR News, I'm Kristian Foden-Vencil in Portland.
BLOCK: That story is part of a partnership with NPR, Oregon Public Broadcasting and Kaiser Health News.