自来水与瓶装水谁更健康?

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.越来越渴

还记得喷泉饮水机吗？曾经它是随处可见的、免费的饮用水来源，但在现代人的眼中它已经一个离奇古怪的东西。取而代之的是无处不在的瓶装水：它遍布于全国的办公室、机场、商场、家庭和酒店。2006年我们消费80亿加仑的瓶装水，比2005年增加了10%。它清爽、无卡路里、携带方便、比自来水好喝，而且比含糖的碳酸饮料要健康得多。但人们正越来越关注这些瓶装水以及其包装的安全性——从最低限度上讲，它是不是比自来水要健康？它的便利是否能与它对环境的影响功过相抵？

瓶中物是什么？

那些响当当的名字和标签描述了田园诗一般的美景，让我们相信瓶中的液体是我们周围最为纯净的水源。“但实际上我们不能认为瓶装水比自来水的处理更加规范、更好地受到保护或是更安全，”NRDC（自然资源保护委员会）的副主任Eric Goldstein如是说。该委员会是致力于健康和环境保护的一个非营利性组织。

的确，部分瓶装水来自于清亮的泉水或其它的自然水源。但超过25%的瓶装水是用自来水制成的。这些水经过处理和纯化后卖给消费者，其价格常常翻了一千倍。许多人对于自己喝的是改头换面后身价百倍的自来水感到大吃一惊，但是并没有规定要求生产商必须在标签上注明水源。

今年Aquafina将开始在标签上注明它采用的水源是公共饮用水。Nestlé Pure Life也将在其瓶子上标明它采用的是公共饮用水、私有水源或地下水。Dasani没有在它的产品包装上，但在其网页上表明了它所采用的是当地的公共饮用水。

标签能产生错误的导向，以次充好。在一个臭名昭张的案例中，多个厂商购买了有害费弃品堆放处附近的地下水以生产瓶装水。其中至少一个生产商在其产品的标签上注明它的产品是由“泉水”制成。另一个案例中，所谓的“冰川水”实际上来源于Alaska的公用饮用水。

来自Minneapolis的38岁的Lisa Ledwidge已经有数年没有饮用瓶装水了，部分原因是她发现许多牌子的瓶装水都是公共饮用水制成的。“你在一加仑的饮用水上花的比等量的汽油还多，而实际上你喝的这些只要打开水龙头就能免费获得，”她说道，“我当时想，为什么我要一边抱怨汽油费一边却又在饮水上花这些冤枉钱呢？但你从没听人抱怨过瓶装水的价格。” Ledwidge说她现在只喝经过滤过的自来水。

争论不仅仅涉及自来水与瓶装水之间的优劣；绝大部分人知道水资源的重要性，他们两者都喝。他们不知道的是有些瓶装水并不像他们想象的那么纯净。1999年，NRDC测试了103个品牌的超过1000瓶水（这是关于瓶装水安全的最新大宗报告）。大部分的瓶装水是安全的，但该组织发现三分之一品牌的至少一个送检样品含有超过国家工业标准的细菌或化学污染物质，包括致癌物质。该报告发表以后，相关的规定并无重大改变，而生产商也未明显更改其生产流程，所以报告中提到的风险仍很有可能存在。

NRDC发现两个品牌的送检样品有邻苯二甲酸盐污染，其中一个样本污染物含量超过了EPA（环境保护协会）规定的自来水邻苯二甲酸盐含量标准。这些化合物可使塑料变得更柔软，化妆品和芳香剂、淋浴门帘，甚至婴儿玩具中都常含有这些物质；对于这些化合物的审查越来越严格。它们能扰乱内分泌系统的功能，直接阻断或通过与内分泌激素相似的结构竞争性地抑制了其正常生理功能。对这些广泛存在的化学物质的暴露可能产生累积效应。

在生长发育的关键时期暴露于高水平的邻苯二甲酸盐，男性胎儿可能发生生殖器官畸形，如睾丸未降等。一些专家认为邻苯二甲酸盐能导致精子数目低下。

瓶子本身并不含这些化学物质，故NRDC所检测到的邻苯二甲酸盐可能来源于生产过程中或水源本身的污染（在某些自来水中可检测到邻苯二甲酸盐）。

为安全起见，瓶装水应受到规范化监测，但相关管理制度却存在漏洞。自来水由EPA规范管理，而瓶装水由FDA（食品与药物管理局）负责。然而经过包装并销售的自来水并不属于FDA的监管范围，这使得约60~70%的瓶装水逃过监察；根据NRDC的报告，这其中包括冷却罐里的水。在这种情况下，瓶装水的测试依赖各州的落实，但NRDC发现各州常常没有足够的人力来监测瓶装水，某些州甚至连一个负责该项工作的全职人员都没有。

FDA要求瓶装水生产商必须定期对污染物含量进行测定，但该机构认为瓶装水是低风险产品，所以并不一定每年都会对其生产过程进行检查。根据FDA官员所言，保证产品符合法律法规标准是生产商的责任。某些生产商请NSF（全国环境卫生基金会）进行产品监测。NSF每年都会对生产车间进行检查，内容包括水源、处理流程及污染物检测等，但检查结果并不向外发布。另一些生产商请IBWA（国际瓶装水协会）进行产品监测。该协会每年也会以不向外发布的形式对产品进行检测，保证其符合FDA的标准。IBWA有自己的一套规程，其中部分比FDA更加严格。

没有规定要求生产商应向消费者告知他们的产品受到了污染，但有时他们会从商店召回产品。来自California州Oakland市太平洋学会的Peter Gleick说，实际上，在1990到2007年间，这样的情况共有约100次。召回的原因包括：霉菌、苯、大肠杆菌和微生物，甚至是蟋蟀的污染。