彭蒙惠英语：The Mercury Mess（在线收听） |
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The Mercury Mess 2 How can we solve the problem? Unfortunately, technologies for reducing mercury emissions from power plants have a long way to go, and even the best U.S. controls won’t touch the clouds of mercury coming from natural sources and from industry abroad. Controls for other pollutants remove some mercury. But the Energy Department and industry are trying to develop technologies specifically aimed at mercury, such as sorbent injection. This process involves shooting carbon dust into smokestacks. The dust binds to the mercury, forming particles that can be sifted from the exhaust. EPA chief Mike Leavitt says he is highly optimistic about the method but believes “it will not be widely deployable until 2010 or after.” Even the best technologies won’t choke off all sources of mercury. While much mercury falls within 100 miles of its source, about one third of U.S. atmospheric mercury comes from natural sources, such as volcanoes around the world. And an additional 21 percent drifts over from power plants in Asia. A lot of the mercury in oceangoing fish also hails from sources abroad. Every little bit counts? That’s why utilities say they’re not entirely to blame. “Reducing mercury emissions from U.S. power plants makes very little difference,” says Vicky Sullivan, environmental issues manager for Southern Company, which operates 21 coal-burning plants in the South. “Not so,” says Harvard University atmospheric chemist Daniel Jacob, “Mercury hot spots downwind of power plants show that local emissions matter,” he says. “Reducing emissions from local plants will not eliminate the problem, but if it is a large local source, it will help.” With all sides in the mercury debate gearing up for a long dispute, there are sure to be more questions for those fishermen bringing in the catch.
Vocabulary Focus deployable (adj) [di5plCiEbl] able to be put in use or action hot spot (n phr) a place with more than usual activity or action gear up (idiom) to prepare for an upcoming action or event Specialized Terms atmospheric (adj) 大气的，与大气有关的 relating to the air or the mixture of gases around the Earth
汞污染 2 我们如何解决这个问题？ 不幸的是，能够降低发电厂汞排放量的科技尚无法一蹴而就，而且即使是美国最好的控制装置，也无法触及自然界和外国工业所带来的汞云。 用来对付其它污染源的控制装置，确实除去了一些汞。但是能源部以及工业界正尝试发展出专门针对汞的科学技术，例如吸着剂注入法。这种处理过程是将碳尘射入烟囱，让它与汞在其中结合，形成在排气口即可筛去的微粒。环保署组长麦克·李维表示，他对这套方法的效果保持高度乐观的态度，但也认为，“至少要到2010年，或更久之后，才能够普遍使用。” 即使最好的科技也无法终结汞的各种来源。虽然大量的汞都掉落在它源头100英里之内，美国大气中还是有1/3的汞含量由自然界产生，例如世界各地的火山。另外的21%则由亚洲的发电厂飘浮而来。远洋鱼类所含大量的汞，也是从海外的源头而来。 每一点都算数吗？ 这就是为什幺电力公司说不能全怪他们。“减少美国发电厂所排放的汞，并不会带来多大的改变，”南方公司环境事务部经理维琪·苏利文这么说，该公司在美国南部经营了21家燃煤火力发电厂。 “未必见得，”哈佛大学大气化学家丹尼尔·雅各说，“在发电厂下风处汞反应活跃的热点，显示出当地的排放同样会造成影响，”他说。“减少当地发电厂的排放虽无法解决问题，但如果该发电厂是当地的主要汞污染来源，还是会有用。” 各方对于汞的不同的看法，意味着一场漫长的争论正要上演，而渔夫所捕回的鱼，未来也势必面对更多质疑。 |
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