EPA Standard for Fluoride in Drinking Water Is Not Protective

Several studies indicate an increased risk of bone fracture in populations exposed to fluoride concentrations in water of 4 mg/L or higher, the committee added. Although fluoride increases bone density as it accumulates in bone, there is evidence that under certain conditions it can weaken bone and increase the risk of fractures. Most of the committee concluded that a population with lifetime exposure to fluoride in water at concentrations of 4 mg/L or higher is likely to experience more fractures than a group exposed to 1 mg/L. Three of the 12 committee members, however, only supported a conclusion that EPA's 4 mg/L limit might not be protective against bone fractures; they said more evidence was needed before drawing a conclusion that increased risk of fracture is likely. There was insufficient data for the committee to reach any conclusions about fracture risk at the 2 mg/L level.

The report also looks at the risk of skeletal fluorosis, a bone and joint condition associated with prolonged exposure to high concentrations of fluoride. The most severe stage of skeletal fluorosis appears to be rare in the United States, the committee noted. It also said that it could not determine if earlier stages of the disease are occurring in U.S. residents who drink water with fluoride at the 4 mg/L level, and that more research is needed in this area.

The evidence to date regarding fluoride's potential to cause cancer, particularly of the bone, is tentative and mixed, the committee added. A study under way at the Harvard School of Dental Medicine, expected to be published this summer, may help identify future research that would be useful for studying fluoride's carcinogenic potential.

The committee's study was sponsored by the U.S. Environmental Protection Agency. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows.

Fluoride in Drinking Water: A Scientific Review of EPA's Standards
Published by the National Research Council
576 pages

Available from the National Academies Press

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NATIONAL RESEARCH COUNCIL
Division on Earth and Life Studies
Board on Environmental Studies and Toxicology

Committee on Fluoride in Drinking Water

John Doull, M.D., Ph.D. (chair)
Professor Emeritus of Pharmacology and Toxicology
University of Kansas Medical Center
Kansas City

Kim Boekelheide, M.D., Ph.D.
Professor
Department of Pathology and Laboratory Medicine
Brown University
Providence, R.I.

Barbara G. Farishian, D.D.S.
Dentist
Washington, D.C.

Robert L. Isaacson, Ph.D.
Distinguished Professor
Department of Psychology
State University of New York
Binghamton

Judith B. Klotz, Dr.P.H.
Adjunct Associate Professor
Department of Epidemiology
University of Medicine and Dentistry of New Jersey
Piscataway

Jayanth V. Kumar, D.D.S., M.P.H.
Director
Oral Health Surveillance and Research Unit
Bureau of Dental Health
New York State Department of Health
Albany

Hardy Limeback, D.D.S., Ph.D.
Associate Professor and Head of Preventive Dentistry
University of Toronto
Toronto

Charles Poole, M.P.H., Sc.D.
Associate Professor
Department of Epidemiology
School of Public Health
University of North Carolina
Chapel Hill

J. Edward Puzas, Ph.D.
Donald and Mary Clark Professor of Orthopaedics
School of Medicine and Dentistry
University of Rochester
Rochester, N.Y.

Nu-May Ruby Reed, Ph.D.
Staff Toxicologist
Department of Pesticide Regulation
California Environmental Protection Agency
Sacramento

Kathleen M. Thiessen, Ph.D.
Senior Scientist
Center for Risk Analysis
SENES Oak Ridge Inc.
Oak Ridge, Tenn.

Thomas F. Webster, D.Sc.
Assistant Professor
Department of Environmental Health
Boston University School of Public Health
Boston

RESEARCH COUNCIL STAFF

Susan N.J. Martel
Project Director

SOURCE: PRESS RELEASE