新闻周刊:水中含毒素敲响美国水安全的警钟(3)(在线收听

Norton, Kansas, had an algae scare on June 19. Pond scum on Sebelius Lake, a reservoir, contaminated a treatment plant with a specific kind of cyanobacteria known to produce anatoxin, which targets the brain and can cause seizures, loss of muscle control and even death.

6月19日,堪萨斯州的诺顿出现了藻类恐慌。西贝利厄斯湖上的池塘浮渣污染了一家处理厂,其中含有一种已知能产生安纳托克毒素的蓝藻细菌,这种细菌可入侵大脑,会导致癫痫发作、肌肉失控,甚至死亡。

When lab results confirmed the species of the algae, the response was swift. The town of Norton immediately stopped drawing water from the reservoir, and the Kansas National Guard arrived hours later to hand out bottled water. Shutting down the reservoir strained the rest of the water system, and when it failed, health officials ordered roughly 3,000 residents to boil their water before drinking it. Officials later confirmed no toxins had entered the public supply.

当实验室结果确认了这种藻类的种类后,迅速应对。诺顿镇立即停止从水库抽水,几小时后堪萨斯国民警卫队赶到现场分发瓶装水。水库的关闭给供水系统带来了压力,当供水系统失灵时,卫生官员下令约3000名居民在饮用之前将水烧开。有关官员后来证实,没有有毒物质进入公共场所。

Boiling water, however, isn’t a solution. Filters will catch the algae themselves—blooms are prone to causing problems by physically blocking filters—but the toxins flow through. And chemical disinfectants like chlorine, which kill algae, can actually make the problem worse, because cyanobacteria release intense bursts of toxins when they die. “There’s really not a lot that you can do,” says Farrer.

然而,烧开水不是解决办法。滤水器会拦截藻类——但藻华容易通过物理阻塞滤水器而引起问题——会让毒素流过。氯等化学消毒剂可以杀死藻类,但实际上会让问题变得更糟,因为蓝藻菌在死亡时会释放出大量毒素。“能够做的真不多,” 法瑞说。

Greenfield, Iowa, experienced a similar scare in mid-July when potentially harmful algae from a bloom on Greenfield Lake managed to slip through a filter in the town water treatment plant.

爱荷华州的格林菲尔德在7月中旬也经历过类似的恐慌,当时格林菲尔德湖爆发的潜在有害藻类成功越过了镇上一家水处理厂的过滤器。

Greenfield Municipal Utilities ordered its 12,000 customers to avoid their tap water until lab results determined whether toxins were indeed present; tests eventually revealed they were not.

格林菲尔德市政公用事业公司命令其1.2万名客户在实验室结果确定是否确实存在毒素之前不要饮用自来水;测试最终显示,毒素远不止污染饮用水。

  原文地址:http://www.tingroom.com/lesson/xwzk/519874.html