【科普】瓶装水与自来水 －－ 究竟哪个更好？
Bottled Or Tap Water - Which Is Best?
Article Date: 28 Mar 2007 - 3:00 PDT
Although bottled water is perceived as a healthier, safer choice over tap water in consumer surveys, that is not necessarily always true, says sports nutritionist Cynthia Sass, R.D., C.S.S.D. In a presentation today at the American College of Sports Medicine (ACSM) 11th-annual Health & Fitness Summit & Exposition in Dallas, Texas, Sass outlined the basics of water consumption, comparing bottled and tap varieties.
"Twenty-five percent of all bottled water is actually repackaged tap water," said Sass. ""The more a consumer knows about the realities of bottled and tap water, the savvier they can be about selecting water based on costs, preferences and accessibility."
Is Bottled Best?
In a recent Gallop survey, most consumers indicated they drink bottled water based on their perception it is safer and purer than tap water. Taste was the second leading reason, while bottled water's convenience was also a factor.
Bottled water is considered a food, and thus regulated by Food and Drug Administration (FDA). Tap water is regulated by the U.S. Environmental Protection Agency (EPA). Both varieties are subject to testing for contaminants, although Sass points out there is no perfect system - both bottled and tap may contain contaminates such as bacteria, arsenic, lead or pesticides. Independent tests by groups such as the National Resources Defense Council have found:
-- Sixty to 70 percent of all bottled water in the United States is packaged and sold within the same state, which exempts it from FDA regulation. One in five states do not regulate that bottled water.
-- While most cities meet the standards for tap water, some tap water in the 19 U.S. cities tested was found to contain arsenic, lead, and pesticides.
-- In 1,000 bottles of 103 different brands of bottled water, 22 percent contained synthetic chemicals, bacteria and arsenic.
Most healthy adults can tolerate trace amounts of these contaminates if exposed, but Sass notes some people are more vulnerable and should be more aware of their water source. These people include cancer patients undergoing chemotherapy, patients who are HIV+ positive or recovering from a transplant or major surgery, and pregnant women, children, and elderly adults.
For them especially, Sass recommends bottled water treated with reverse osmosis, municipal tap water with a filtering system certified by the National Sanitation Foundation (NSF) or distilled water. (Most packaging on certified filter devices bear the NSF seal.)
According to Sass, other selection criteria for consumers may include:
Cost: Bottled water can cost approximately $1 for a gallon jug, while tap water costs pennies on the dollar. Distilled water or water treated with reverse osmosis (water captured into vapor so that all solids are left behind and then recaptured into fluid) are purer and considered safe, but are also more expensive.
Marketing: Fitness and specialty waters do not contribute to an athletic advantage or edge. In fact, vitamin-fortified waters, which provide high daily-value percentages per cup, may pose a risk for oversupplementation. "Think of your one-a-day vitamin," says Sass. "Some of these waters are multi-vitamins in a bottle, so read the label and compare with the rest of your daily intake, including food."
"Bottled water doesn't deserve the nutritional halo that most people give it for being pure," she says. "If you're not an exclusive bottled water drinker, you may find it worthwhile to check into filtering your tap water to save money."
The Summit is presented this year with the National Academy of Sports Medicine (NASM) as an educational partner.
The American College of Sports Medicine is the largest sports medicine and exercise science organization in the world. More than 20,000 International, National and Regional members are dedicated to promoting and integrating scientific research, education and practical applications of sports medicine and exercise science to maintain and enhance physical performance, fitness, health and quality of life. 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 Bottled Or Tap Water - Which Is Best?
Article Date: 28 Mar 2007 - 3:00 PDT
Although bottled water is perceived as a healthier, safer choice over tap water in consumer surveys, that is not necessarily always true, says sports nutritionist Cynthia Sass, R.D., C.S.S.D.
In a presentation today at the American College of Sports Medicine (ACSM) 11th-annual Health & Fitness Summit & Exposition in Dallas, Texas, Sass outlined the basics of water consumption, comparing bottled and tap varieties.
作者:admin@医学,生命科学 2010-12-26 05:14