In “Fluoride Study Out” (Colorado Daily, 3/23/06) numeric data for fluoride levels in drinking water is presented in a way that may well be confusing for many readers. First the writer states that the EPA limit for fluoride is 4 milligrams per liter (mg/L) of water, and then he cites that Boulder fluoridates its drinking water to roughly 0.9 parts per million (ppm). Unfortunately, the article gives no indication of the relationship between these quantities.
The relationship becomes clear, however, if one knows that 1 ppm is equal to 1 mg/L. Thus, the 0.9 ppm level of fluoridation in Boulder’s water is equal to 0.9 mg/L, or slightly less than one-fourth of the EPA maximum contaminant level goal (MCLG) for fluoride which is set at 4 mg/L, or 4 ppm.
To help visualize 1 part per million, this is roughly equivalent to about 1 drop in 16 gallons, or to about 4 drops in a 55-gallon barrel.
The preceding was originally published as a letter to the editor of the Colorado Daily on March 28, 2006.
This message is from the Vote No on 2B Committee,
supported by the many very concerned health professionals serving the people of Boulder.
