NCPA - National Center for Policy Analysis


July 28, 2005

Questions about fluoridation have returned because of allegations of scientific misconduct against a prominent researcher at the Harvard School of Dental Medicine. The Environmental Working Group, an advocacy organization in Washington, charged last month that Chester Douglass misrepresented an unpublished study about bone cancer and fluoridated tap water.

The study was conducted by one of his doctoral students, Elise Bassin. She started with the same raw data as her mentor -- 139 people with osteosarcoma (a rare bone cancer) and 280 healthy "controls" -- but saw a way to improve on it. Since most of the 400 people diagnosed in the United States each year with osteosarcoma are kids, and since any ill effect of fluoride would likely come when bones are growing most quickly, she focused on the 91 patients who were under 20.

Her result:

  • Among boys drinking water with 30 to 99 percent of the fluoride levels recommended by the U.S. Centers for Disease Control and Prevention, the risk of osteosarcoma was estimated to be five times as great as among boys drinking nonfluoridated water.
  • At 100 percent or more, the risk was an estimated seven times as high; the association was greatest for boys six to eight.

To be sure, one study proves nothing. Moreover, Bassin hasn't published her core findings (though in 2004 she and colleagues published a description of their methodologies). However, Boston University's Kenneth Rothman called it "of publishable quality."

Zeroing in on young patients, he says, was good science: "If there were an adverse effect of fluoride, it's possible an effect of early exposure would be manifest in the first 20 years of life -- but not after." Looking at all ages, in other words, could conceal any link between fluoridation and cancer.

Source: Sharon Begley, "Fluoridation, Cancer: Did Researchers Ask the Right Questions?" Wall Street Journal, July 22, 2005.

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