pbs高端访谈:危险化学品六价铬污染美国饮水系统

 　　JEFFREY BROWN:And now to part two of our investigative look at the safety of America's drinking water.

　　Science correspondent Miles O'Brien reports on the toxic¹ chemical made famous in the movie "Erin Brockovich," its potentially harmful effect on human cells, and the agency charged with regulating it.

　　His report is the result of a partnership² with the Center for Public Integrity.

　　AMIE HOLMES, University of Southern Maine: There is some lead chromate in here and some zinc³ chromate.

　　MILES O’BRIEN:At the Wise Laboratory at the University of Southern Maine, they are very wise indeed about a widely used heavy metal that gives millions of Americans shiny bumpers⁴, vivid paint, and, possibly, cancer. It is hexavalent chromium, or chromium 6.

　　AMIE HOLMES:As you can see, there's a lot of different colors to chromium.

　　MILES O’BRIEN:Yes.

　　And there are many shades of gray to the story, right?

　　AMIE HOLMES:Yes.

　　MILES O’BRIEN:Chromium 6 was also used as a coolant here at a natural gas pumping station owned by Pacific Gas & Electric in Hinkley, Calif. The utility dumped 26 tons of the chemical into unlined holding ponds in the 1950s and '60s. It leeched⁵ into the groundwater, poisoning the wells.

　　The health fallout and the David and Goliath legal battle against PG&E became the basis for the 2000 movie "Erin Brockovich" starring Julia Roberts.

　　JULIA ROBERTS, Actress: People are dying, Scott. You have got document after document here. Right under your nose, it says why, and you haven't said one word about it. I want to know how the hell you sleep at night.

　　MILES O’BRIEN:Hinkley is not alone.

　　Public utility testing records reveal more than 70 million Americans are now drinking tap water tainted⁶ by chromium 6.

　　AMIE HOLMES:This is what happens when the cells are exposed to chromium.

　　MILES O’BRIEN:Wise researcher Amie Holmes showed me what scientists can say for certain about the link between chromium 6 and cancer. These are slides of human lung cells in the midst of replicating⁷, a process called mitosis.

　　In normal cells, there are two centrosomes, the yellowish-white dots. They search and capture 46 chromosomes⁸ each, then pull apart, making an identical daughter cell.

　　AMIE HOLMES:You want to make sure that each cell has the same amount of DNA⁹ in each.

　　MILES O’BRIEN:Take a look at these lung cells exposed to chromium 6. Notice the yellowish-white centrosomes? Instead of two, there are four.

　　AMIE HOLMES:What's going to happen, and when this cell divides, instead of dividing into two, it could potentially pull the DNA into four or it's going to unevenly¹⁰ separate the DNA.

　　MILES O’BRIEN:With four centrosomes, it's not going to end well.

　　AMIE HOLMES:It's not going to end well.

　　MILES O’BRIEN:Scientists call this centrosome amplification¹¹. They suspect chromium 6 changes the chemistry of the proteins in our cells, and that creates the extra centrosomes.

　　The resulting defective¹² cells that survive are what we call cancer.

　　JOHN WISE, University of Southern Maine: Yes, it causes cancer. That's the biggest health concern.

　　MILES O’BRIEN:We know that for sure?

　　JOHN WISE:Right. Yes.

　　MILES O’BRIEN:There's no doubt about that?

　　JOHN WISE:There's no doubt about it. It's considered a human carcinogen by all the major regulatory agencies in the world.

　　MILES O’BRIEN:So, what's in here?

　　JOHN WISE:Cells.

　　MILES O’BRIEN:Lab director John Wise can say that with certainty chromium 6 is carcinogenic when inhaled¹³, occupational exposure in factories. But when the chemical is ingested in the stomach, it is a murkier¹⁴ picture.

　　Sandy Wise offered me a demonstration¹⁵. Water that is heavily contaminated with chromium 6, like this, turns bright yellow. Now watch what happens when she adds vitamin C, which is acidic, not unlike the human stomach.

　　SANDY WISE, University of Southern Maine: So, you can see it's starting to change color.

　　MILES O’BRIEN:The water turns green as the chromium 6 is transformed into trivalent chromium, or chromium 3.

　　Our cells don't absorb chromium 3 as they do chromium 6. So the human stomach offers a natural antidote¹⁶ to chromium 6 in water. But what are the limits of this alchemy?

　　John Wise says we can't say for certain.

　　JOHN WISE:There's just holes in the data, so there's a lot that we don't know.

　　MILES O’BRIEN:What more science needs to be done?

　　JOHN WISE:I don't think we have enough studies to tell us whether—clearly whether it's a drinking water carcinogen or not.

　　MILES O’BRIEN:But there are studies that make the link. In 2008, the National Institutes of Health weighed in with an eye-opening rodent¹⁷ study. It uncovered clear evidence that high doses of chromium 6 in drinking water caused cancer in rats and mice.

　　MILES O’BRIEN:Does it settle anything in your view?

　　JOHN WISE:I think that starts the conversation as to perhaps maybe it is a drinking water carcinogen, but it's just one study that needs additional work.

　　MILES O’BRIEN:In 2011, Wise joined eight colleagues on a panel that advised the EPA on the science that would be used to set a new standard for chromium 6 contamination in U.S. tap water.

　　The current standard, set 20 years ago, is 100 parts per billion, 5,000 times higher than the state of California's public health goal for chromium 6 in drinking water. Wise was among panelists who voted to delay a decision, allowing time for more study. At first, the agency said it needed another four years, even though it began the work in 2008.

　　The chromium standard is bogged¹⁸ down in IRIS¹⁹, the Integrated Risk Information System, which aims to insure the best science is employed as the EPA considers regulating risky²⁰ chemicals.

　　That's the idea. But the National Academy of Sciences has blasted IRIS for using faulty methodology, and not being clear and transparent²¹. And the Government Accountability Office criticized IRIS for moving way too slowly. The GAO estimates it takes the EPA an average of about seven years to complete a scientific assessment²² of a chemical.

　　Anger and frustration²³ over the logjam boiled over at this IRIS stakeholders meeting in November.

　　Richard Denison is with the Environmental Defense²⁴ Fund.

　　RICHARD DENISON, Environmental Defense Fund: Now, these delays have profound real-world consequences. They allow continued exposure and harm to health from the subject chemicals, because decisions that rely on IRIS are also delayed. Simply put, a decision delayed is health protection denied.

　　MILES O’BRIEN:So, why is the process so bogged down? The first clue comes from who showed up at the stakeholders meeting.

　　KATHLEEN ROBERTS, North American Metals Council: My name is Kathleen Roberts. I am with the North American Metals Council.

　　KIMBERLY WISE, American Chemistry Council: My name is Kimberly Wise. I am with the American Chemistry Council.

　　NINA HALLMARK, ExxonMobil Chemical: Good afternoon. My name is Nina Hallmark. I am with ExxonMobil Chemical.

　　RICK BECKER, American Chemistry Council: Thanks. Rick Becker with American Chemistry Council.

　　NANCY BECK, American Chemistry Council: Thanks. Nancy Beck, American Chemistry Council.

　　MILES O’BRIEN:Representatives of chemical manufacturers and their trade association, the American Chemistry Council, dominated the meeting.

　　David Fischer is a senior director at ACC.

　　MILES O’BRIEN:Is industry kind of overwhelming this process?

　　DAVID FISCHER, American Chemistry Council: No, I would say definitely not. Our member companies are populated by any number of employees, including scientists who perhaps have spent their careers studying a particular chemical that might be the subject of an IRIS assessment. So it stands to reason that all that important experience and knowledge should be brought to bear on the IRIS process.

　　MILES O’BRIEN:But the NewsHour and the Center for Public Integrity have learned the chemical industry is close to the scientific review process as well.

　　Although John Wise says he hasn't accepted any funding from industry in 15 years, two of his colleagues on the chromium 6 panel worked for PG&E during the Hinkley legal battles. And one of them, Joshua Hamilton of the Marine²⁵ Biological Lab at Woods Hole, got a call from PG&E asking him to work as a consultant²⁶ while he was serving on EPA's chromium 6 review panel.

　　The panel held its meeting on May 12, 2011. PG&E paid Hamilton to address a town hall meeting at the regional water board that governs Hinkley on June 8, 2011.

　　JOSHUA HAMILTON, Marine Biological Lab, Woods Hole: I am an independent toxicologist asked by PG&E to come here and speak about chromium health issues.

　　MILES O’BRIEN:The peer review report was released a month later. Dr. Hamilton declined our requests for an on-air interview. He later told us he reported his potential conflict to the government contractor²⁷ that manages peer reviews for the EPA and that they decided²⁸ this didn't represent a conflict of interests, particularly since he would participate in the panel before engaging with PG&E in the town hall meeting.

　　We did speak with PG&E. Sheryl Bilbrey is director of the chromium remediation team.

　　SHERYL BILBREY,Pacific Gas & Electric: And his role has been to explain the toxicity²⁹ of hexavalent chromium. He's not discussed any part of the regulatory process.

　　Well, again, PG&E expects anyone that works for us, that they will maintain their professional integrity and be completely independent of any regulatory process. So we wouldn't expect Josh to—or Dr. Hamilton to change any of his advice.

　　MILES O’BRIEN:Sometimes, though, the appearance of a conflict is a conflict, isn't it?

　　SHERYL BILBREY:Well, I don't think so, I think as long as everyone knows that Dr. Hamilton does work for us. And he is very well-respected, so I think his credentials³⁰ really speak for him.

　　MILES O’BRIEN:At the stakeholders meeting, the acting³¹ director of IRIS, Vincent Cogliano, vowed³³ to make some changes in the program.

　　VINCENT COGLIANO, Integrated Risk Information System: And in addition, we will post the names of potential reviewers before the meeting so that we can get public comment on the expertise³⁴ and the conflicting interests of our reviewers. It is a shame that we don't have the highest-quality peer review and the most impartial³⁵ peer review that we can get.

　　MILES O’BRIEN:In a written statement, the EPA claims it is committed to using the best science, working to improve the IRIS review process and reduce any potential conflict of interests by increasing transparency and public input³⁶.

　　Despite that vow³², the EPA refused our repeated requests for an interview. During the course of our five-month investigation³⁷, the agency did make a new promise, to decide on an updated chromium 6 standard in another year, instead of four. But what are they waiting for? A $4 million dollar study funded by the American Chemistry Council, which represents the chemical industry.

　　Ann Mason is a senior director with ACC.

　　ANN MASON, American Chemistry Council: So, essentially³⁸, Miles, ACC and its members do not have any direct link with any of the researchers that are part of this study.

　　MILES O’BRIEN:Right. But you're writing the check for the study?

　　ANN MASON:We're writing the check for the study, but in the process of putting this together, we have got a study director who is in direct link. We do not have any contact with the research -- researchers, nor with the peer review process. So we are trying to be as arm's-length away from this, the actual conduct of the work, as possible.

　　MILES O’BRIEN:In the U.S., industry doesn't need to prove a chemical is safe before it is used commercially. The chemical, not the people, get the benefit of the doubt. And so delays inevitably³⁹ favor industry.

　　Dr. Wise, what's the matter with setting a level and then continuing the science? And if the science tells you, hey, we can raise it a little bit later, do so.

　　JOHN WISE:That is certainly an approach one could take. It's just not typically the—it's the way these things are done, I guess. It's not—levels don't change all that often. It seems to be a fairly cumbersome⁴⁰, slow, expensive process.

　　MILES O’BRIEN:Cumbersome, slow and expensive, in Washington, that seems to be just part of the chemical equation.

　　JUDY WOODRUFF:Online, you can watch Miles' first report, explore a graphic⁴¹ that tracks chromium levels across the country, and find tips on how to remove the chemical from your drinking water. That's all on our Science page.

1 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

2 partnership   

n.合作关系，伙伴关系

参考例句：

• The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
• Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。

3 zinc   

n.锌；vt.在...上镀锌

参考例句：

• Brass is formed by the fusion of copper and zinc.黄铜是通过铜和锌的熔合而成的。
• Zinc is used to protect other metals from corrosion.锌被用来保护其他金属不受腐蚀。

4 bumpers   

（汽车上的）保险杠，缓冲器( bumper的名词复数 )

参考例句：

• Our bumpers just grazed (ie touched each other) as we passed. 我们错车时保险互相蹭了一下。
• Car stickers can be attached to the bumpers or windows. 汽车贴纸可以贴在防撞杆上或车窗上。

5 leeched   

v.用水蛭吸血（leech的过去式与过去分词形式）

参考例句：

• Her relatives leeched her for her money like parasites. 她的亲戚像寄生虫似地榨取她的钱财。 来自辞典例句
• A group of silly young girls leeched onto the popular singer. 一群傻姑娘死缠着那个流行歌手。 来自互联网

6 tainted   

adj.腐坏的；污染的；沾污的；感染的v.使变质( taint的过去式和过去分词 )；使污染；败坏；被污染，腐坏，败坏

参考例句：

• The administration was tainted with scandal. 丑闻使得政府声名狼藉。
• He was considered tainted by association with the corrupt regime. 他因与腐败政府有牵连而名誉受损。 来自《简明英汉词典》

7 replicating   

复制( replicate的现在分词 )； 重复； 再造； 再生

参考例句：

• Applications create these partitions for storing and replicating data. 应用程序创建这些分区用来储存和复制数据。
• The closest real things to these creatures were bits of self-replicating RNA. 最贴近这些造物的实物是能做一点微不足道的自复制的核糖核酸。

8 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

9 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

10 unevenly   

adv.不均匀的

参考例句：

• Fuel resources are very unevenly distributed. 燃料资源分布很不均匀。
• The cloth is dyed unevenly. 布染花了。

11 amplification   

n.扩大，发挥

参考例句：

• The voice of despair may be weak and need amplification.绝望的呼声可能很微弱，需要扩大。
• Some of them require further amplification.其中有些内容需进一步详细阐明。

12 defective   

adj.有毛病的，有问题的，有瑕疵的

参考例句：

• The firm had received bad publicity over a defective product. 该公司因为一件次品而受到媒体攻击。
• If the goods prove defective, the customer has the right to compensation. 如果货品证明有缺陷， 顾客有权索赔。

13 inhaled   

v.吸入( inhale的过去式和过去分词 )

参考例句：

• She closed her eyes and inhaled deeply. 她合上双眼，深深吸了一口气。
• Janet inhaled sharply when she saw him. 珍妮特看到他时猛地吸了口气。 来自《简明英汉词典》

14 murkier   

adj.阴暗的( murky的比较级 )；昏暗的；（指水）脏的；混浊的

参考例句：

• If not, the outcome may be a lot murkier. 而如不然，结果可能就会更加含糊不清。 来自互联网
• This leads us into the murkier areas of human behaviour. 这让我们看到了人类行为较阴暗的领域。 来自互联网

15 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。

16 antidote   

n.解毒药，解毒剂

参考例句：

• There is no known antidote for this poison.这种毒药没有解药。
• Chinese physicians used it as an antidote for snake poison.中医师用它来解蛇毒。

17 rodent   

n.啮齿动物；adj.啮齿目的

参考例句：

• When there is a full moon,this nocturnal rodent is careful to stay in its burrow.月圆之夜，这种夜间活动的啮齿类动物会小心地呆在地洞里不出来。
• This small rodent can scoop out a long,narrow tunnel in a very short time.这种小啮齿动物能在很短的时间里挖出一条又长又窄的地道来。

18 bogged   

adj.陷于泥沼的v.（使）陷入泥沼， （使）陷入困境( bog的过去式和过去分词 )；妨碍，阻碍

参考例句：

• The professor bogged down in the middle of his speech. 教授的演讲只说了一半便讲不下去了。 来自《现代英汉综合大词典》
• The tractor is bogged down in the mud. 拖拉机陷入了泥沼。 来自《简明英汉词典》

19 iris   

n.虹膜，彩虹

参考例句：

• The opening of the iris is called the pupil.虹膜的开口处叫做瞳孔。
• This incredible human eye,complete with retina and iris,can be found in the Maldives.又是在马尔代夫，有这样一只难以置信的眼睛，连视网膜和虹膜都刻画齐全了。

20 risky   

adj.有风险的，冒险的

参考例句：

• It may be risky but we will chance it anyhow.这可能有危险，但我们无论如何要冒一冒险。
• He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。

21 transparent   

adj.明显的，无疑的；透明的

参考例句：

• The water is so transparent that we can see the fishes swimming.水清澈透明，可以看到鱼儿游来游去。
• The window glass is transparent.窗玻璃是透明的。

22 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

23 frustration   

n.挫折，失败，失效，落空

参考例句：

• He had to fight back tears of frustration.他不得不强忍住失意的泪水。
• He beat his hands on the steering wheel in frustration.他沮丧地用手打了几下方向盘。

24 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

25 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

26 consultant   

n.顾问；会诊医师，专科医生

参考例句：

• He is a consultant on law affairs to the mayor.他是市长的一个法律顾问。
• Originally,Gar had agreed to come up as a consultant.原来，加尔只答应来充当我们的顾问。

27 contractor   

n.订约人，承包人，收缩肌

参考例句：

• The Tokyo contractor was asked to kick $ 6000 back as commission.那个东京的承包商被要求退还6000美元作为佣金。
• The style of house the contractor builds depends partly on the lay of the land.承包商所建房屋的式样，有几分要看地势而定。

28 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

29 toxicity   

n.毒性，毒力

参考例句：

• The hoarse grunt or squeal is characteristic of toxicity.嘶哑的哼声和叫声是中毒的特征。
• Dieldrin is related to aldrin,and its toxicity to earthworms is similar.狄氏剂与艾氏剂有关，对蚯蚓的毒性是相似的。

30 credentials   

n.证明，资格，证明书，证件

参考例句：

• He has long credentials of diplomatic service.他的外交工作资历很深。
• Both candidates for the job have excellent credentials.此项工作的两个求职者都非常符合资格。

31 acting   

n.演戏，行为，假装；adj.代理的，临时的，演出用的

参考例句：

• Ignore her,she's just acting.别理她，她只是假装的。
• During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。

32 vow   

n.誓(言)，誓约；v.起誓，立誓

参考例句：

• My parents are under a vow to go to church every Sunday.我父母许愿，每星期日都去做礼拜。
• I am under a vow to drink no wine.我已立誓戒酒。

33 vowed   

起誓，发誓（vow的过去式与过去分词形式）

参考例句：

• He vowed quite solemnly that he would carry out his promise. 他非常庄严地发誓要实现他的诺言。
• I vowed to do more of the cooking myself. 我发誓自己要多动手做饭。

34 expertise   

n.专门知识(或技能等)，专长

参考例句：

• We were amazed at his expertise on the ski slopes.他斜坡滑雪的技能使我们赞叹不已。
• You really have the technical expertise in a new breakthrough.让你真正在专业技术上有一个全新的突破。

35 impartial   

adj.(in,to)公正的，无偏见的

参考例句：

• He gave an impartial view of the state of affairs in Ireland.他对爱尔兰的事态发表了公正的看法。
• Careers officers offer impartial advice to all pupils.就业指导员向所有学生提供公正无私的建议。

36 input   

n.输入(物)；投入；vt.把(数据等)输入计算机

参考例句：

• I will forever be grateful for his considerable input.我将永远感激他的大量投入。
• All this information had to be input onto the computer.所有这些信息都必须输入计算机。

37 investigation   

n.调查，调查研究

参考例句：

• In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
• He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。

38 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

39 inevitably   

adv.不可避免地；必然发生地

参考例句：

• In the way you go on,you are inevitably coming apart.照你们这样下去，毫无疑问是会散伙的。
• Technological changes will inevitably lead to unemployment.技术变革必然会导致失业。

40 cumbersome   

adj.笨重的，不便携带的

参考例句：

• Although the machine looks cumbersome,it is actually easy to use.尽管这台机器看上去很笨重，操作起来却很容易。
• The furniture is too cumbersome to move.家具太笨，搬起来很不方便。

41 graphic   

adj.生动的，形象的，绘画的，文字的，图表的

参考例句：

• The book gave a graphic description of the war.这本书生动地描述了战争的情况。
• Distinguish important text items in lists with graphic icons.用图标来区分重要的文本项。