December 28, 1989

Fluoride Linked to Bone Cancer in Fed Study

by Joel Griffiths

FLUORIDE appears to have caused bone cancer in rodents in a recently completed National Toxicology Progran (NTP) study, and the chemical is now at risk of being classified a carcinogen, according to internal documents and statements obtained by MEDICAL TRIBUNE from the Environmental Protection Agency (EPA).

"Early this year, EPA received a phone call from NTP informing us that the preliminary pathology results from their study indicated there were some bone tumors that may have been causally related to fluoride," this newspaper was told by Peter Cook, deputy director for the office of drinking water, EPA.

The study - which has taken a decade to complete - was designed to officially settle the question of whether fluoride is a carcinogen. The pathology results were submitted to NTP by the contract lab last February. The phone call to EPA came soon afterward.

"It [the phone call] was most unusual," continued Mr. Cook, "because NTP had not yet completed their own review of the pathology materials. Apparently they felt that, because of the potential impact of the findings, EPA should be informed aas soon as possible."

EPA officially regards the results as being of only anecdotal validity, Mr. Cook emphasized. However, as of early December, NTP's review was virtually complete, and no further communication had come from NTP to suggest that the results had been invalidated, he acknowledged.

John Bucher, Ph.D., chemical director of the NTP study, declined to discuss the results. He said they may be released this month. NTP is part of the Department of Health and Human Services.

'Very Preliminary Data'

This newspaper also obtained a briefing paper that was prepared by EPA staff scientists for a meeting between EPA and the American Water Works Association (AWWA). The meeting took place last September. The paper states in part: "Very preliminary data from recent health studies on fluoride indicate that fluoride may be a carcinogen." The "preliminary data" referred to, according to Mr. Cook, are those from the NTP study. The paper continues: "If the ongoing review of the fluoride drinking water standard results in a more stringent standard based on this new information, the number of PWS [public water supplies] in violation will increase dramatically. This would impact many PWS and be extremely costly to treat."

A participant in the September meeting, John H. Sullivan, AWWA deputy executive director for government affairs, put it another way: "If fluoride turns out to be a carcinogen, it will be the environmental story of the century," he told the MEDICAL TRIBUNE. "And if our members have to start removing fluoride from drinking water, their job will be mind-boggling." Mr. Sullivan, however, disclaimed any knowledge of the NTP results.

In its 1985 review of the evidence on the health effects of low levels of fluoride, EPA found nothing to indicate any significant risks to the population, and in 1986 the agency raised the amount of fluoride in U.S. drinking water (MT, April 27, 1989).

Moreover, early this year, the agency said it intended to skip its routine review of the fluoride drinking-water standard because no new evidence had emerged in the interim.

'Call it a Coverup'

Then, last summer - following the phone call from NTP - the agency abruptly changed its mind. Now, a full EPA review of the evidence on the health effects of fluoride is scheduled for next year and "will solicit new information that will impact the 1986 standard," according to EPA water analyst Cynthia Puskar.

A contributing factor may have been internal pressure from EPA's union of professional employees - Local 2050 of the National Federation of Federal Employees - which has been campaigning against what it perceives as politicization of science at the agency, using fluoride as a case in point. According to the local's president, Robert Carton, Ph.D., EPA's 1985 review of fluoride health effects was "a shoddy job, bordering on scientific fraud. You could call it a coverup."

Fluoridation of drinking water to prevent dental caries began in the late 1940s, and currently more than 60% of U.S. public water supplies are fluoridated. Studies have indicated that, as a result, small amounts of fluoride are present in the teeth and bones of most of the U.S. population and are widely distributed throughout the biosphere and the food supply as well. Most toothpastes and dentrifices contain added fluoride, and fluoride supplements are commonly prescribed for children and pregnant women. Fluoridation measures have received the near-unanimous support of public-health officials and organized dentistry and medicine, who have pronounced them beneficial and safe.

NTP's rodent bioassay of fluoride carcinogenicity was mandated by Congress in 1977, in response to public concern over epidemiological studies by John Yiamouyiannis, Ph.D., president of the Safe Water Foundation of Delaware, Ohio, and the late Dean Burk, Ph.D., former head of the National Cancer Institute's cytochemical section. They reported a 5% increase in cancer rates in cities having fluoridated water supplies. Subsequent studies by other investigators failed to confirm these findings. Completion of the NTP study has been delayed be technical problems and tardy results from the contract lab, according to Dr. Bucher. "But we have almost completed our review of the pathology materials, and we hope to affix our seal of approval and make the results public this January."