Walkdown the drinks section at the supermarket.Look in the drink cooler in yourlocal convenience store.A new drink is taking up more and more space on theshelves，and that drink iswater.Bottled water sales in the US rose to 1.7 billion gallons in 2010 forplastic bottles alone，compared to totalsales of only 700 million gallons in 1990.Whereas bottled water was onceassociated only with the rich and the privileged (特权阶层)，it is now regularlydrunk by people at all income levels despite the fact that the price of bottledwater can be between 240 and 10,000 times higher per gallon than tap water.Whataccounts for this surprising increase in demand?

Traditionally，people have drunk bottled water for health reasons.Thepractice of “taking the waters” originated with the Romans，who believed that aperson developed a healthy mind by building a healthy body.Across Europe，drinking or bathing in mineral water has been associatedwith the power to cure various diseases.Health spas at Evian in France andPellegrino in Italy began bottling water so that their consumers could continuetheir treatments at home.The consumers in the 21st century are also concernedabout health.However，in America，where the habit of drinking bottled water is relatively new，the concern is often more related to the purity orsterilization (消毒) of the water thanto its mineral contents.Americans are often worried about the effects of thechemical pollution and other contaminants on the water supply.ManyAmericans view bottled water as a safe alternative to tap water.

Furtherreasons for drinking bottled water are its usefulness as an aid to digestion，as a complement to a good meal in a restaurant，and for taste.City tap water is often treated with chlorine(氯) to guard against harmful micro­organisms.Chlorine，as well as metals from pipes and tanks used to distributeand store tap water，can leave behind anunpleasant taste.