People who buy bottled water for its perceived purity may not be getting what they're paying for. They're most likely not getting adequate fluoride either, according to researchers at Case Western Reserve University and Ohio State University.

In a study published in the March issue of the "Archives of Family Medicine," a journal of the American Medical Association, researchers compared the bacterial content and fluoride levels of 57 samples of bottled water with tap water from each of Cleveland's four water treatment plants.

"Only three bottled waters ... had fluoride levels within the range recommended by the Ohio Environmental Protection Agency," according to James Lalumandier, a CWRU assistant professor of dentistry, and Leona W. Ayers of OSU's College of Medicine and Public Health. The other 54 bottles fell short of the recommended range of 0.80 to 1.30 milligrams of fluoride per liter.

All Cleveland tap water samples, however, were not only within the accepted range but also scored very near the optimal level of 1.00 milligrams per liter.

Bacterial counts in the four tap water samples varied only slightly, from 0.2 to 2.7 bacterial colonies per milliliter. In the bottled water, bacterial counts ranged from less than 0.01 to 4,900 colonies per milliliter. Six bottled waters had bacteria counts of 1,500 to 4,900 colonies per milliliter.

"One of the reasons people choose to drink bottled water instead of tap water is because of the perceived purity of bottled water," the researchers observe, and indeed, 39 samples of bottled water were found to be purer than the tap water. However, 15 samples of bottled water had significantly higher bacteria levels than the tap water. Of these 15, the bacteria counts were more than twice as high as the most contaminated tap water sample and almost 2,000 times higher than the purest tap water sample.

Technicians at the Ohio Department of Health Laboratories in Columbus tested the water samples, which th
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Contact: Judith Bailey
jcb4@po.cwru.edu
216-368-4442
Case Western Reserve University
20-Mar-2000