新闻周刊:水中含毒素敲响美国水安全的警钟(2)

（单词翻译）

One expert estimates that more than 90 percent of lakes, rivers and reservoirs used as drinking water sources in the United States are vulnerable to algal blooms. Equally troubling: The majority of water treatment plants aren’t equipped to remove toxins³, which require pricey treatment methods like ozone⁴ disinfection. When the algae⁵ interfere⁶ with drinking supplies, timely remedies can be hard to come by, leaving some towns with no choice but to order the residents to stop using tap water, sometimes for weeks at a time. Although municipal water managers are reluctant to talk publicly about the issue, “they’re very worried,” says Deepak Mishra, an associate professor of geography at the University of Georgia who studies the global distribution of harmful algal blooms.

据一位专家估计，美国90%以上的作为饮用水源的湖泊、河流和水库，都容易受到藻华的影响。同样令人不安的是，大多数水处理厂都没有配备清除毒素的设备，这需要臭氧消毒等昂贵的处理方法。当藻类干扰饮用水供应时，很难找到及时的补救措施，这使得一些城镇别无选择，只能命令居民停止使用自来水，有时一次甚至停止使用数周。虽然市政供水管理人员不愿公开谈论这个问题，“但他们非常担心，”乔治亚大学研究有害藻华全球分布的地理学副教授迪帕克·米什拉说。

So far, nobody has died from algal toxins in the U.S., but the possibility looms¹. A high enough dose of microcystin could cause liver or kidney failure, says David Farrer, a public health toxicologist with the Oregon Health Authority. A combination of microcystin and cylindrospermopsin, another potentially deadly toxin², is thought to have killed 52 people in Brazil in 1996, though they were dialysis patients who suffered intravenous exposure to contaminated tap water during treatment.

到目前为止，美国还没有人死于海藻毒素，但这种可能性正在增大。高剂量的微囊藻毒素会导致肝肾功能衰竭，俄勒冈州卫生局的公共卫生毒理学家大卫·法瑞尔说道。1996年，巴西死亡52人，后认为死因是一种微囊藻毒素和另一种可能致命的毒素圆柱精蛋白的组合，虽然他们是透析患者，在治疗过程中静脉暴露在受污染的自来水中。

Comprehensive data on algae contamination in the U.S. is lacking, largely because municipalities are not required to test for it. Some states and townships began testing a decade or so ago, but the benchmarks water administrators⁷ use to determine if the water is safe to drink are largely preliminary—the Environmental Protection Agency implemented⁸ its first trial protocol⁹ just this year.

美国缺乏有关藻类污染的全面数据，主要是因为市政当局不需要对其进行检测。约十年前，一些州和乡镇开始进行测试，但水管理人员确定饮用水是否安全的基准是初步的——就在今年，美国环境保护署实施了首个试点议定书。