[Dan.Linehan]

I wrote the Marin County water board to see if the water has fluoride in it.

Sure enough, it does.

Hi Dan,

Yes, the water provided by MMWD contains fluoride. Fluoride occurs naturally in almost all surface and ground waters. In this area, the natural concentration is 0.1 milligrams per liter. Following a voter initiative by MMWD customers in 1972, the fluoride level was increased to 0.9 milligrams per liter, the optimum for cavity prevention. California now requires fluoridation by all public water supplies that serve populations over 10,000.

State and federal regulations have set limits on the maximum concentration of fluoride in drinking water. These limits take into consideration that fluoride is also consumed via toothpaste, mouthwash, foods, and beverages. The primary federal standard is 4 PPM to prevent skeletal fluorosis and the federal secondary standard (for aesthetic factors) is 2 PPM to prevent dental fluorosis, a cosmetic darkening of the teeth. California regulations are typically more stringent than federal standards. The California primary and secondary regulatory limits in California are 2.4 PPM and 1.2 PPM respectively. For drinking water meeting either regulation, there are no adverse health effects and the limits provide for an ample margin of safety.

Please consider that there are many water sources (particularly groundwater) with naturally occurring fluoride levels at optimal (about 1 PPM) concentration and also at levels far above optimum (2 to 4 PPM). People have consumed naturally fluoridated water for generations and health researchers have studied the effects on generation after generation. The vast body of science-based, peer-reviewed research has found that there is a comfortable margin of safety between the optimal dose for cavity prevention and a dose that would create any health effect.

Here are some links to information about fluoridation:

From the National Cancer Institute
Fluoridated Water: Questions and Answers - National Cancer Institute

And from the American Dental Association
ADA.org: A-Z Topics: Fluoride & Fluoridation

And from the American Medical Association
JAMA -- Achievements in Public Health, 1900-1999: Fluoridation of Drinking Water to Prevent Dental Caries, March 8, 2000, 283 (10): 1283

Fluoride Fact Sheet from Los Angeles, which has recently started fluoridation and has compiled many links to national and California health organizations that support fluoridation including American Dental Association, American Medical Association, US Surgeon General, US Center for Disease Control, and many others.

LADWP: Fluoridation Fact Sheet

Sincerely,
Libby Pischel