How Safe Is Your Drinking Water?
"The purification process may or may not be excellent," says Levin. Although bottling companies may have good filtration equipment, there's no guarantee that they clean their filters or promptly fix filters that break, she says. Indeed, one study published in the Archives of Family Medicine conducted by researchers at Case Western Reserve University found that 15 of 39 bottled water samples had bacterial counts nearly twice as high as Cleveland tap water. The highest had more than 2,000 times the amount of bacteria found in the clearest tap water.
Bottled water critics also point out that plastics can leach chemicalsincluding such tongue-twisters as phthalates and bisphenol Athat disrupt hormones and seem to cause problems such as infertility and cancer in lab animals. However, according to the National Association for PET Container Resources (NAPCOR), containers made of polyethylene terephthalate (PET), the type that most bottled water is sold in, contain neither bisphenol A nor the phthalates that critics worry about. (For more information, see "The Safety of PET Bottles.") Nevertheless, Levin is sufficiently concerned about chemical hazards that she tries to avoid foods and liquids that have been stored in plastic containers.
But most experts say that, in this country, both tap and bottled water are remarkably safe. About 12 times as many Americans are killed by lightning each year as are killed by outbreaks of water-borne diseases.
"In general, there is not a significant difference in the health risk between bottled and tap water," says Marc Edwards, a drinking water expert at Virginia Tech. But he notes that in certain situationsif a community's tap water is known to have high lead levels, for example, or a person has an immune system too compromised to fend off waterborne pathogensbottled water is probably the better bet.