自來水與瓶裝水誰更健康?

By Janet Majeski JemMott

You're spending more per gallon than you would on gasoline for this thing that you can get out of the tap virtually for free ... I wondered, Why am I spending this money while complaining about how much gas costs? But you don't ever hear anyone complain about the price of bottled water.

Growing Thirst

Remember the drinking fountain, that once ubiquitous, and free, source of H2O? It seems quaint now. Instead, bottled water is everywhere, in offices, airplanes, stores, homes and restaurants across the country. We consumed over eight billion gallons of the stuff in 2006, a 10 percent increase from 2005. It's refreshing, calorie-free, convenient to carry around, tastier than some tap water and a heck of a lot healthier than sugary sodas. But more and more, people are questioning whether the water, and the package it comes in, is safe, or at least safer than tap water -- and if the convenience is worth the environmental impact.

What's in That Bottle?
Evocative names and labels depicting pastoral scenes have convinced us that the liquid is the purest drink around. "But no one should think that bottled water is better regulated, better protected or safer than tap," says Eric Goldstein, co-director of the urban program at the Natural Resources Defense Council (NRDC), a nonprofit organization devoted to protecting health and the environment.

Yes, some bottled water comes from sparkling springs and other pristine sources. But more than 25 percent of it comes from a municipal supply. The water is treated, purified and sold to us, often at a thousandfold increase in price. Most people are surprised to learn that they're drinking glorified tap water, but bottlers aren't required to list the source on the label.

This year Aquafina will begin stating on labels that its H2O comes from public water sources. And Nestlé Pure Life bottles will indicate whether the water comes from public, private or deep well sources. Dasani acknowledges on its website, but not on the label itself, that it draws from local water.

Labels can be misleading at best, deceptive at worst. In one notorious case, water coming from a well located near a hazardous waste site was sold to many bottlers. At least one of these companies labeled its product "spring water." In another case, H2O sold as "pure glacier water" came from a public water system in Alaska.

Lisa Ledwidge, 38, of Minneapolis, stopped drinking bottled water a couple of years ago, partly because she found out that many brands come from a municipal supply. "You're spending more per gallon than you would on gasoline for this thing that you can get out of the tap virtually for free," she says. "I wondered, Why am I spending this money while complaining about how much gas costs? But you don't ever hear anyone complain about the price of bottled water." Ledwidge says she now drinks only filtered tap water.

The controversy isn't simply about tap vs. bottled water; most people drink both, knowing the importance of plenty of water. What they may not know is that some bottled water may not be as pure as they expect. In 1999 the NRDC tested more than 1,000 bottles of 103 brands of water. (This is the most recent major report on bottled water safety.) While noting that most bottled water is safe, the organization found that at least one sample of a third of the brands contained bacterial or chemical contaminants, including carcinogens, in levels exceeding state or industry standards. Since the report, no major regulatory changes have been made and bottlers haven't drastically altered their procedures, so the risk is likely still there.

The NRDC found that samples of two brands were contaminated with phthalates, in one case exceeding Environmental Protection Agency (EPA) standards for tap water. These chemicals, used to make plastic softer, are found in cosmetics and fragrances, shower curtains, even baby toys, and are under increasing scrutiny. They're endocrine disrupters, which means they block or mimic hormones, affecting the body's normal functions. And the effects of exposure to the widespread chemicals may add up.

When exposed to high levels of phthalates during critical developmental periods, male fetuses can have malformed reproductive organs, including undescended testicles. Some experts link phthalates to low sperm counts.

Water bottles do not contain the chemical, which means the phthalates detected by the NRDC probably got into the water during processing at the bottling plant, or were present in the original water source (phthalates have been found in some tap water).

Bottled water is regulated for safety, but it's a tricky thing. The EPA regulates tap water, while the FDA oversees bottled. Yet FDA oversight doesn't apply to water packaged and sold within the same state, leaving some 60 to 70 percent of bottled water, including the contents of watercooler jugs, free of FDA regulation, according to the NRDC's report. In this case, testing depends on the states, but the NRDC found that they often don't have adequate resources to oversee bottled water, in some cases lacking even one full-time person for an entire state.

The FDA requires bottlers to regularly test for contaminants, but the agency considers bottled water a low-risk product, so plants may not be inspected every year. According to one FDA official, it's the manufacturer's responsibility to ensure that the product complies with laws and regulations. Some bottlers turn to NSF International, a trade group that conducts yearly unannounced inspections of plants, looking at the source of the water and the treatment process, and testing for contaminants. Other companies belong to the International Bottled Water Association (IBWA), which also performs annual unannounced tests to ensure the plant is up to FDA standards. IBWA has its own regulations, some of which are stricter than the FDA's.

Bottlers don't have to let consumers know if their product becomes contaminated, but sometimes they pull their products from stores. In fact, between 1990 and 2007, this happened about 100 times, says Peter Gleick of the Pacific Institute in Oakland, California. Among the reasons for recall: contamination with mold, benzene, coliform, microbes, even crickets.越來越渴

還記得噴泉飲水機嗎？曾經它是隨處可見的、免費的飲用水來源，但在現代人的眼中它已經一個離奇古怪的東西。取而代之的是無處不在的瓶裝水：它遍佈於全國的辦公室、機場、商場、家庭和酒店。2006年我們消費80億加侖的瓶裝水，比2005年增加了10%。它清爽、無卡路里、攜帶方便、比自來水好喝，而且比含糖的碳酸飲料要健康得多。但人們正越來越關注這些瓶裝水以及其包裝的安全性——從最低限度上講，它是不是比自來水要健康？它的便利是否能與它對環境的影響功過相抵？

瓶中物是什麼？

那些響噹噹的名字和標籤描述了田園詩一般的美景，讓我們相信瓶中的液體是我們周圍最爲純淨的水源。“但實際上我們不能認爲瓶裝水比自來水的處理更加規範、更好地受到保護或是更安全，”NRDC（自然資源保護委員會）的副主任Eric Goldstein如是說。該委員會是致力於健康和環境保護的一個非營利性組織。

的確，部分瓶裝水來自於清亮的泉水或其它的自然水源。但超過25%的瓶裝水是用自來水製成的。這些水經過處理和純化後賣給消費者，其價格常常翻了一千倍。許多人對於自己喝的是改頭換面後身價百倍的自來水感到大吃一驚，但是並沒有規定要求生產商必須在標籤上註明水源。

今年Aquafina將開始在標籤上註明它採用的水源是公共飲用水。Nestlé Pure Life也將在其瓶子上標明它採用的是公共飲用水、私有水源或地下水。Dasani沒有在它的產品包裝上，但在其網頁上表明瞭它所採用的是當地的公共飲用水。

標籤能產生錯誤的導向，以次充好。在一個臭名昭張的案例中，多個廠商購買了有害費棄品堆放處附近的地下水以生產瓶裝水。其中至少一個生產商在其產品的標籤上註明它的產品是由“泉水”製成。另一個案例中，所謂的“冰川水”實際上來源於Alaska的公用飲用水。

來自Minneapolis的38歲的Lisa Ledwidge已經有數年沒有飲用瓶裝水了，部分原因是她發現許多牌子的瓶裝水都是公共飲用水製成的。“你在一加侖的飲用水上花的比等量的汽油還多，而實際上你喝的這些只要打開水龍頭就能免費獲得，”她說道，“我當時想，爲什麼我要一邊抱怨汽油費一邊卻又在飲水上花這些冤枉錢呢？但你從沒聽人抱怨過瓶裝水的價格。” Ledwidge說她現在只喝經過濾過的自來水。

爭論不僅僅涉及自來水與瓶裝水之間的優劣；絕大部分人知道水資源的重要性，他們兩者都喝。他們不知道的是有些瓶裝水並不像他們想象的那麼純淨。1999年，NRDC測試了103個品牌的超過1000瓶水（這是關於瓶裝水安全的最新大宗報告）。大部分的瓶裝水是安全的，但該組織發現三分之一品牌的至少一個送檢樣品含有超過國家工業標準的細菌或化學污染物質，包括致癌物質。該報告發表以後，相關的規定並無重大改變，而生產商也未明顯更改其生產流程，所以報告中提到的風險仍很有可能存在。

NRDC發現兩個品牌的送檢樣品有鄰苯二甲酸鹽污染，其中一個樣本污染物含量超過了EPA（環境保護協會）規定的自來水鄰苯二甲酸鹽含量標準。這些化合物可使塑料變得更柔軟，化妝品和芳香劑、淋浴門簾，甚至嬰兒玩具中都常含有這些物質；對於這些化合物的審查越來越嚴格。它們能擾亂內分泌系統的功能，直接阻斷或通過與內分泌激素相似的結構競爭性地抑制了其正常生理功能。對這些廣泛存在的化學物質的暴露可能產生累積效應。

在生長髮育的關鍵時期暴露於高水平的鄰苯二甲酸鹽，男性胎兒可能發生生殖器官畸形，如睾丸未降等。一些專家認爲鄰苯二甲酸鹽能導致精子數目低下。

瓶子本身並不含這些化學物質，故NRDC所檢測到的鄰苯二甲酸鹽可能來源於生產過程中或水源本身的污染（在某些自來水中可檢測到鄰苯二甲酸鹽）。

爲安全起見，瓶裝水應受到規範化監測，但相關管理制度卻存在漏洞。自來水由EPA規範管理，而瓶裝水由FDA（食品與藥物管理局）負責。然而經過包裝並銷售的自來水並不屬於FDA的監管範圍，這使得約60~70%的瓶裝水逃過監察；根據NRDC的報告，這其中包括冷卻罐裏的水。在這種情況下，瓶裝水的測試依賴各州的落實，但NRDC發現各州常常沒有足夠的人力來監測瓶裝水，某些州甚至連一個負責該項工作的全職人員都沒有。

FDA要求瓶裝水生產商必須定期對污染物含量進行測定，但該機構認爲瓶裝水是低風險產品，所以並不一定每年都會對其生產過程進行檢查。根據FDA官員所言，保證產品符合法律法規標準是生產商的責任。某些生產商請NSF（全國環境衛生基金會）進行產品監測。NSF每年都會對生產車間進行檢查，內容包括水源、處理流程及污染物檢測等，但檢查結果並不向外發佈。另一些生產商請IBWA（國際瓶裝水協會）進行產品監測。該協會每年也會以不向外發布的形式對產品進行檢測，保證其符合FDA的標準。IBWA有自己的一套規程，其中部分比FDA更加嚴格。

沒有規定要求生產商應向消費者告知他們的產品受到了污染，但有時他們會從商店召回產品。來自California州Oakland市太平洋學會的Peter Gleick說，實際上，在1990到2007年間，這樣的情況共有約100次。召回的原因包括：黴菌、苯、大腸桿菌和微生物，甚至是蟋蟀的污染。