Dear Ms.:
Your appeal of January 19, 2003, was received and referred to the appropriate professional concerning fluoridation. We believe that the CDC statement that "Extensive research conducted over the past 50 years has shown that fluoridation of public water supplies is a safe and effective way to reduce tooth decay for all community residents" is supported by extensive peer-reviewed scientific research. The CDC presentation of the fluoride information is comprehensive, informative, and understandable within the context of its intended purpose and no corrective actions are necessary. Further, after carefully reviewed the information you provided, we would like to note all of the following:
In your letter, you hypothesizes that many cases of arthritis are misdiagnosed and that they are actually cases of chronic fluoride poisoning exhibiting symptoms of joint pain. However, there is no evidence that consumption of optimally fluoridated water (0.7 to 1.2 mg/L fluoride), even in conjunction with other typical daily fluoride exposures (i.e. toothpaste, foods and beverages prepared with fluoridated water) causes symptoms of joint pain that mimics arthritis.
Several of the more recent reviews on the safety of fluoride intake have discussed skeletal fluorosis, which is extremely rare in the United States. Epidemiological studies in the U.S. of communities with naturally occurring fluoride in the water 3.3 to 8 times the amount in optimally adjusted water supplies found no evidence of skeletal fluorosis. Pages 45-47 of the 1991 Department of Health and Human Services document Review of Fluoride: Benefits and Risks discusses the topic of skeletal fluorosis topic in more detail and provides references. Only 5 cases of skeletal fluorosis have ever been reported in the U.S. In these cases, the total fluoride intake was 15 to 20 mg./fluoride per day for 20 years.
Regarding early symptoms of skeletal fluorosis, the 1997 Institute of Medicine (IOM) report on Dietary Reference Intakes for Calcium, Phosphorus, Vitamin D, and Fluoride stated that "The development of skeletal fluorosis and its severity is directly related to the level and duration of exposure. Most epidemiological research has indicated that an intake of at least 10mg. per day for 10 or more years is needed to produce clinical signs of the milder forms (arthritis like symptoms, and some radiographically evident osteosclerosis of pelvis and vertebrae) of the disease." This daily intake level necessary to produce skeletal fluorosis or even its early signs far exceeds that level of fluoride received by people on fluoridated community water systems even when factoring in other daily fluoride exposures typical in the U.S.
The IOM report also states (page 307) that "the primary functional adverse effect associated with excess fluoride intake is skeletal fluorosis. In the asymptomatic, preclinical stage of skeletal fluorosis, patients have slight increases in bone mass that are detectable radiographically, bone ash fluoride concentrations that range from 3,500 to 5,500 mg/kg, and bone concentrations that are 2 to 5 times higher than those of life-long residents of optimally fluoridated communities (Eble DM, Deaton TG, Wilson FC Jr., Bawden JW. Fluoride concentrations in human and rat bone. Journal of Public Health Dentistry, 52(5):288-91, 1992). Stage 1 skeletal fluorosis is characterized by occasional stiffness or pain in joints and some osteosclerosis of the pelvis and vertebra. Bone ash fluoride concentrations usually range from 6,000 to 7,000 mg/kg.
For further detail and references regarding this topic, you may want to consult the following sources:
U.S. Department of Health and Human Services, Public Health Service. 1991, Review of Fluoride Benefits and Risks.
MMWR 2001 Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States Vol. 50 No. RR-14
Institute of Medicine, 1997. Dietary Reference Intakes for Calcium, Phosphorus, Vitamin D and Fluoride.
We appreciate your comments and concerns and hope that the information we provide helps clarify the status of fluoridation research in the United States and our efforts to communicate it to the public.
Sincerely,
Dixie E. Snider, M.D., M.P.H.
Assistant Surgeon General
Associate Director of Science
Centers for Disease Control and Prevention
Last Revised: August, 2004