研究生英语精读教程课文原文翻译短文unit2

Cancer & Chemicals

-Are We Going Too Far?

Marla Cone

Last year, California governor George Deukmejian called together many of the state's best scientific minds to begin implementing Proposition 65, the state's Safe Drinking Water and Toxic Enforcement Act. This new law bans industries from discharging chemical suspected of causing cancer (carcinogens) or birth defects into water supplies. Some claim it will also require warning labels on everything that might cause cancer.

去年，加利福尼亚州州长乔治·德米加召集本州许多优秀的科学家开会，开始执行第65号提案，即州安全饮用水和毒品实施法案。这一新法令禁止各工业部门向水源中排放被怀疑致癌和引起先天缺陷的化学物质。有些人宣称，新法律还要求在一切可能致癌的物品上贴上警告标签。

A day of esotericscience and incomprehensible jargonwas predicted. But Bruce Ames, chairman of the department of biochemistry at the University of California at Berkeley, had plans to liven the proceedings.

原来预计，开会那天将全是些玄妙的科学和难懂的术

语，但加州大学伯克利分校生物化学系系主任布鲁斯·爱姆兹却打算使会议开得更有生气。

Walking into the room, Ames looked like the quintessential scientist: wire-rimmedbifocals, rumpled suit, tousled hair and a sallow complexion that showed he spent more time in his laboratory than in the California sunshine.As someone intoned about the mechanisms of carcinogenesis, Ames began to interject his own views.

当爱姆兹走入会议室时，他看上去完全是一个典型的科学家形象：金丝边双光眼镜，皱褶的西服，蓬乱的头发，菜色的面庞，显示出他总是呆在实验室里而很少享受加州的阳光。当某人振振有词地大谈致痛机理时，爱姆兹开始打断他，插进来陈述自己的观点。

"The whole world is chock-full of carcinogens," Ames declared.“ A beer, with its 700 parts per billion of formaldehyde and five parts per 100 of alcohol is a thousand times more hazardous than anything in the water. If you have beer on your breath, does that mean you have to warn everyone who comes within ten feet of you?"

“整个世界都充满了致癌物”，爱姆兹宣称。“啤酒中有十亿分之七百的甲醛和百分之五的乙醇，比水中的任何物质都要危险1 000倍。如果你呼出的气息中有啤酒味，那是否意

味着你必须向你周围10英尺以内的所有人发出警告?”

In an era when headlines shout about the latest cancer scare, Ames has a different message: the levels of most man-made carcinogens are generally so low that any danger is trivial compared with the levels of natural carcinogens.

在大肆宣传最新癌症恐怖的时代里，爱姆兹带来了不同的信息：大多数人造致癌物的含量一般来说都很低。与天然致癌物含量相比其危险微乎其微。

Ames is not a quack. At age 59, he is one of the nation's most respected authorities on carcinogenesis. His resume is packed with honors, including the Charles. Mott Prize from the General Motors Cancer Research Foundation, one of the most prestigious awards in cancer research, and membership in the National Academy of Sciences.Even his critics say the Ames test—his simple, inexpensive laboratory procedure that helps determine whether a substance might cause cancer—is a remarkable achievement.

爱姆兹不是个冒充内行的人。他59岁，是全国最受人尊敬的研究致癌问题的权威之一。他的简历中尽是各种荣誉，包括通用汽车癌症研究基金会颁发的查尔斯·莫特奖(这

是痛症研究中最富声誉的嘉奖之一)。他还是国家科学院的院士。甚至他的批评者们也承认，爱姆兹试验是一项突出的成就。这种试验是在实验室里进行的一种简单廉价的操作方法，它有助于检测一种物质是否能引起癌症。

But Ames slaughters sacred cows. He's taking on the environmental movement, which some have called the single most important social movement of the 20th century. In April 1987, for instance, he and two colleagues, Renae Magaw and Lois Swirsky Gold, published a report in Science magazine that ranked various possible cancer risks.Based on animal tests of nearly 1,000 chemicals, the data show that daily consumption of the average peanut-butter sandwich, which contains traces of aflatoxin (a naturally occurring mold carcinogen in peanuts), is 100 times more dangerous than our daily intake of DDT from food, and that a glass of the most polluted well water in the Silicon Valley is 1,000 times less of cancer risk than a glass of wine or beer is.He's not advising people to stop consuming peanut-butter, beer and wine. What he's saying is that most cancer risks created by man are trivial compared with everyday natural risks, and it's not clear how many of these are real risks. Both types distract

attention from such enormous risk factors as tobacco.

但是爱姆兹藐视一切貌似神圣不可冒犯的东曲。他对环境保护运动的观点提出不同看法，有些人把这一运动称为20世纪最重要的运动。例如，1987年4月，他和两位同事雷纳·玛格和露易·斯沃斯基·戈尔德，在《科学》杂志上发表了一篇报告，列举了各种各样可能引起癌症的危险。以将近1 000种化学物质作的动物试验所得到的数据表明，每日所消耗的普通花生酱三明治中含有的微量黄曲霉素(花生中天然存在的一种霉菌致癌物)比我们每同从食物中摄取DDT的危险大100倍。一杯硅谷污染最严重的井水比一杯葡萄酒或啤酒致癌的危险要小1 000倍。他并不是建议人们停止消费花生酱、葡萄酒和啤酒。他所说的是，大多数人造致癌物的危险比起日常天然物的致癌危险是微不足道的。现在不清楚它们中有多少有真正的危险。这曲种危险都转移了人们对于诸如烟草之类的巨人危险的注意力。

Ames's cancer research began about 25 years ago over a bag of potato chips. Ames, then conducting research for the National Institutes of Health in Maryland, was reading the ingredients on the bag. It struck him that no one knew what each chemical did to human genes , and there was no easy way to find out.

爱姆兹的癌症研究是25年前以一袋炸薯条开始的。当

时他在马里兰全国健康研究所从事研究工作。在看到袋上列出的成分时，他突然想到还没有人知道每种化学物质对人的基因有什么影响，而要了解这些还没有简易的方法。

At that time, scientists testing for carcinogenicity had to set up time consuming and costly lab experiments on rats and mice. Armed with the knowledge that bacteria are sensitive to substances that cause mutation, and that carcinogens were likely to be mutagens, Ames developed a carcinogen test using bacteria. The Ames test was hailed as a major scientific development and is now used worldwide.

那时，科学家为了测试致癌性，不得不在老鼠身上做耗时费钱的实验室试验。细菌对引起突变的物质很敏感，而致痛物很可能就是引起突变的物质。爱姆兹凭借这些知识，研究出了一种利用细菌检测致癌性的试验。爱姆兹试验被公认是一项主要的科学成果。现在在世界上已被广泛应用。

One day in 1974 Ames, now teaching at Berkeley, suggested that some students test various household products. To his surprise, many common hair dyes tested positive, as did a flame retardant used in children's pajamas. Almost overnight, Ames became a hero of environmentalists when his findings led to new regulations and bans on certain chemicals.

1974年的一天，当时在伯克利任教的爱姆兹建议一些学生对各种各样家用产品进行检测。使他惊异的是，像用于儿童睡衣中的一种阻燃剂一样，许多普通染发剂经测试都呈阳性。当爱姆兹的测试结果导致对某些化学品实行新的规定和禁令时几乎一夜之间，他就成了环保界的英雄。

For the next decade public concern over carcinogens continued to rise. "Then," Ames says, "I started realizing something wasn't right." Too many natural substances also tested positive as carcinogens or mutagens: fruit juices, brown mustard , celery , parsley .In fact, about half of all chemicals tested by Ames—both natural and man-made—turned out to be potentially carcinogenic when given in enormous doses to rats and mice.

随后10年间，公众对致癌物越来越关注。爱姆兹说“于是我开始意识到有些不对头。”同样也被检测为致癌物或致突变物而呈阳性的天然物数量太多了：水果汁，芥菜，芹菜，欧芹等。实际上，爱姆兹测试的大约一半的化学物，当用老鼠进行大剂量实验时，无论是天然或人造的都证明有潜在的致癌作用。

Ames at first assumed he had erred with his test. He hadn't. His error had been making the common, but naive, assumption that only man-made chemicals could be

dangerous. "Why assume nature is benign?" he now says.

起初，爱姆兹断定他的试验有问题。他的试验并没有错。他的错误在于他象很多人一样天真地认为只有人造化学物质是危险的。他现在要问：“为什么要推断天然就是无害的呢?”

The campaign supporting California's Proposition 65 convinced Ames that he had a duty to explain this to the public. "When people said certain birth defects were caused by a part per billion of something in the water, I thought it irresponsible, " he says. "It's just playing with people's fears. You can always find a part per billion of something in the water."

支持加州65号提案的运动使爱姆兹确信他有义务向公众解释这一点。“当人们说某些先天缺陷是由水中十亿分之一的某物质引起时，我认为那是不负责任的。”他说，“那是拿人们的害怕心理开玩笑。你总能在水中找到十亿分之一的某种物质。”

In testimonybefore a California senate committee, Ames noted that tap water, for instance, contains the carcinogen chloroform at about 83 ppb due to chlorination.But coffee contains two natural carcinogens at about 4,000 ppb each, while human blood averages 3,000

ppb of formaldehyde from normal metabolism.

在加州参议院委员会作证时，爱姆兹举出丁一个例子：由于用氯消毒，自来水含有致癌物氯仿大约十亿分之八十三．。咖啡含有两种天然致癌物，每一种都是大约十亿分之四千，而由于正常的新陈代谢，人血平均含有甲醛十亿分之三干。

Some people assume Ames is a stooge for the chemical industry, which he is not. He does no consulting for the chemical, drug or food companies, or for law firms. And he accepts no grants from business.

有些人想当然地认为爱姆兹是化学工业的代言人。情况却并非如此。他不为化学公司、药品公司、食品公司或法律事务所提供咨询。他没有接受来自商界的任何好处。

Environmentalists reject Ames's arguments, saying that we are obligated to keep the total exposure to carcinogens as low as possible. "Somehow he thinks there has to be a choice," says Carl Pope of the Sierra Club. "If we had to choose between TCE [a suspected cancer causing solvent] in drinking water and public education on cigarette smoking, maybe he's right. But we don't have to make a choice." 环境保护论者反对爱姆兹的观点。他们说，我们有义务在总量上使人们尽可能少地接触致癌物。“不知为

什么他认为要进行选择。”峰峦俱乐部的卡尔·波普这样说：“如果我们不得不在饮用水中的TCE(一种可疑的致癌溶剂)和有关吸烟的公共教育之间进行选择的话，可能他是对的。但是我们不是非去选择不可。”

Ames's reply:"You don't want every chemical company dumping their garbage out the back door. But the price you pay for living in a modern, industrial society is a few parts per billion of chemicals in the water. You can get rid of it, but at enormous cost. If you spend all your time chasing trivia, you lose sight of the important risks."

爱姆兹的回答是，“你不想让每家化学公司从后门倒掉自己的垃圾，但是你生活在现代工业社会的代价就是水里会有十亿分之几的化学物质。你能除去它，但花费巨大。如果你把你所有的时间都花在追查微不足道的东西上，你就会看不到重要的危险。”

Supplementary Reading

Mystery - and Maybe Danger - in the Air Can electricity cause cancer? In a society that literally

runs on electric power, the very idea seems preposterous. But for more than a decade, a growing band of scientists and journalists has pointed to studies that seem to link exposure to electromagnetic fields with increased risk of leukemia and other malignancies.The implications are unsettling, to say the least, since everyone comes into contact with such fields, which are generated by everything electrical, from power lines and antennas to personal computers and microwave ovens. Because evidence on the subject is inconclusive and often contradictory, it has been hard to decide whether concern about the health effects of electricity is legitimate.

Now the alarmists have gained some qualified support from the U.S. Environmental Protection Agency. In the executive summary of a new scientific review, released in draft form late last week, the EPA has put forward what amounts to the most serious government warning to date.The agency tentatively concludes that scientific evidence "suggests a causal link" between extremely low-frequency electromagnetic fields - those having very long wavelengths - and leukemia, lymphoma and brain cancer. While the report falls short of classifying ELF fields

as probable carcinogens, it does identify the common 60-hertz magnetic field as "a possible, but not proven, cause of cancer in humans".

The report is no reason to panic - or even to lose sleep. If there is a cancer risk, it is a small one. The evidence is still so controversial that the draft stirred a great deal of debate within the Bush Administration, and the EPA released it over strong objections from the Pentagon and the White House.

At the heart of the debate is a simple and well understood physical phenomenon: when an electric current passes through a wire, it generates an electromagnetic field that exerts forces on surrounding objects. For many years, scientists dismissed any suggestion that such forces might be harmful, primarily because they are so extraordinarily weak.

Doubts about weak, so-called nonionizing radiation began to grow in 1979, when a study of cancer rates among Colorado schoolchildren found that those who lived near power lines had two to three times as great a chance of developing cancer. The link seemed so unlikely that when power companies paid to have the original

study replicated, most scientists expected the results to be negative.In fact, the subsequent study supported the original findings, which have since been buttressed by reports showing increased cancer rates among electrical workers.

While many experts still express skepticism, there has been a definite shift of attitude in the scientific community about the possible health effects of electromagnetic fields, as a recent series in Science magazine made clear.

But epidemiological studies, which find statistical associations between sets of data, do not prove cause and effect. Though there is a body of laboratory work showing that exposure to ELF fields can have biology effects on animal tissues, a mechanism by which those effects could lead to cancerous growths has never been found.

Meanwhile, ordinary citizens can exercise what is called prudent avoidance - doing relatively easy things to minimize a possible risk. This is not the time to sell, tear apart or rebuild a home. But it might make sense to shift a child's bed away from the electric line that brings power to the house.Or to move the telephone answering machine away from the head of the bed. It isn't hard to take a step

back from the TV or computer screen, and it could make a big difference in the long run.