unit2 lxl some possible resaons for cancer.doc

Cancer & Chemicals-Are We Going Too Far?Marla ConeLast year, California governor George Deukmejian called together many of the states best scientific minds to begin implementing Proposition 65, the states 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，加利福尼亞州州長(zhǎng)喬治德米加召集本州許多優(yōu)秀的科學(xué)家開(kāi)會(huì)，開(kāi)始執(zhí)行第65號(hào)提案，即州安全飲用水和毒品實(shí)施法案。這一新法令禁止各工業(yè)部門向水源中排放被懷疑致癌和引起先天缺陷的化學(xué)物質(zhì)。有些人宣稱，新法律還要求在一切可能致癌的物品上貼上警告標(biāo)簽。A day of esoteric/mysterious/ science and incomprehensible jargon/terminology/ was predicted. But Bruce Ames, chairman of the department of biochemistry at the University of California at Berkeley, had plans to liven the proceedings.原來(lái)預(yù)計(jì)，開(kāi)會(huì)那天將全是些玄妙的科學(xué)和難懂的術(shù)語(yǔ)，但加州大學(xué)伯克利分校生物化學(xué)系系主任布魯斯愛(ài)姆茲卻打算使會(huì)議開(kāi)得更有生氣。Walking into the room, Ames looked like the quintessential/ typical being a perfect example of a particular type of person or thing / scientist: wire-rim med bifocals, 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/talked/ about the mechanisms of carcinogenesis, Ames began to interject/make a sudden remark/ his own views.當(dāng)愛(ài)姆茲走入會(huì)議室時(shí)，他看上去完全是一個(gè)典型的科學(xué)家形象：金絲邊雙光眼鏡，皺褶的西服，蓬亂的頭發(fā)，菜色的面龐，顯示出他總是呆在實(shí)驗(yàn)室里而很少享受加州的陽(yáng)光。當(dāng)某人振振有詞地大談致痛機(jī)理時(shí)，愛(ài)姆茲開(kāi)始打斷他，插進(jìn)來(lái)陳述自己的觀點(diǎn)。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? “整個(gè)世界都充滿了致癌物”，愛(ài)姆茲宣稱?！捌【浦杏惺畠|分之七百的甲醛和百分之五的乙醇，比水中的任何物質(zhì)都要危險(xiǎn)1 000倍。如果你呼出的氣息中有啤酒味，那是否意味著你必須向你周圍10英尺以內(nèi)的所有人發(fā)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.在大肆宣傳最新癌癥恐怖的時(shí)代里，愛(ài)姆茲帶來(lái)了不同的信息：大多數(shù)人造致癌物的含量一般來(lái)說(shuō)都很低。與天然致癌物含量相比其危險(xiǎn)微乎其微。Ames is not a quack/bad doctor/. At age 59, he is one of the nations most respected authorities on carcinogenesis. His resume/life period 履歷/ is packed with honors, including the Charles Mott Prize from the General Motors Cancer Research Foundation, one of the most prestigious/famous/ awards in cancer research, and membership in the National Academy of Sciences. Even his critics say the Ames testhis simple, inexpensive laboratory procedure that helps determine whether a substance might cause canceris a remarkable achievement.愛(ài)姆茲不是個(gè)冒充內(nèi)行的人。他59歲，是全國(guó)最受人尊敬的研究致癌問(wèn)題的權(quán)威之一。他的簡(jiǎn)歷中盡是各種榮譽(yù)，包括通用汽車癌癥研究基金會(huì)頒發(fā)的查爾斯莫特獎(jiǎng)(這是痛癥研究中最富聲譽(yù)的嘉獎(jiǎng)之一)。他還是國(guó)家科學(xué)院的院士。甚至他的批評(píng)者們也承認(rèn)，愛(ài)姆茲試驗(yàn)是一項(xiàng)突出的成就。這種試驗(yàn)是在實(shí)驗(yàn)室里進(jìn)行的一種簡(jiǎn)單廉價(jià)的操作方法，它有助于檢測(cè)一種物質(zhì)是否能引起癌癥。But Ames slaughters/kill animals/ sacred cows/bull/. Hes 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/黃曲霉毒素/ (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. Hes not advising people to stop consuming peanut-butter, beer and wine. What hes saying is that most cancer risks created by man are trivial compared with everyday natural risks, and its not clear how many of these are real risks. Both types distract attention from such enormous risk factors as tobacco/smoke tobacco/.但是愛(ài)姆茲藐視一切貌似神圣不可冒犯的東曲。他對(duì)環(huán)境保護(hù)運(yùn)動(dòng)的觀點(diǎn)提出不同看法，有些人把這一運(yùn)動(dòng)稱為20世紀(jì)最重要的運(yùn)動(dòng)。例如，1987年4月，他和兩位同事雷納瑪格和露易斯沃斯基戈?duì)柕?，在科學(xué)雜志上發(fā)表了一篇報(bào)告，列舉了各種各樣可能引起癌癥的危險(xiǎn)。以將近1 000種化學(xué)物質(zhì)作的動(dòng)物試驗(yàn)所得到的數(shù)據(jù)表明，每日所消耗的普通花生醬三明治中含有的微量黃曲霉素(花生中天然存在的一種霉菌致癌物)比我們每同從食物中攝取DDT的危險(xiǎn)大100倍。一杯硅谷污染最嚴(yán)重的井水比一杯葡萄酒或啤酒致癌的危險(xiǎn)要小1 000倍。他并不是建議人們停止消費(fèi)花生醬、葡萄酒和啤酒。他所說(shuō)的是，大多數(shù)人造致癌物的危險(xiǎn)比起日常天然物的致癌危險(xiǎn)是微不足道的?，F(xiàn)在不清楚它們中有多少有真正的危險(xiǎn)。這曲種危險(xiǎn)都轉(zhuǎn)移了人們對(duì)于諸如煙草之類的巨人危險(xiǎn)的注意力。Amess 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/ composition, component, mixture / 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.愛(ài)姆茲的癌癥研究是25年前以一袋炸薯?xiàng)l開(kāi)始的。當(dāng)時(shí)他在馬里蘭全國(guó)健康研究所從事研究工作。在看到袋上列出的成分時(shí)，他突然想到還沒(méi)有人知道每種化學(xué)物質(zhì)對(duì)人的基因有什么影響，而要了解這些還沒(méi)有簡(jiǎn)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/change/, and that carcinogens were likely to be mutagens/cause mutation substance/, Ames developed a carcinogen test using bacteria. The Ames test was hailed as a major scientific development and is now used worldwide.那時(shí)，科學(xué)家為了測(cè)試致癌性，不得不在老鼠身上做耗時(shí)費(fèi)錢的實(shí)驗(yàn)室試驗(yàn)。細(xì)菌對(duì)引起突變的物質(zhì)很敏感，而致痛物很可能就是引起突變的物質(zhì)。愛(ài)姆茲憑借這些知識(shí)，研究出了一種利用細(xì)菌檢測(cè)致癌性的試驗(yàn)。愛(ài)姆茲試驗(yàn)被公認(rèn)是一項(xiàng)主要的科學(xué)成果?，F(xiàn)在在世界上已被廣泛應(yīng)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/liquid/ tested positive, as did a flame retardant/ materials that inhibit or resist the spread of fire / used in childrens pajamas/sleeping clothes/. 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，當(dāng)時(shí)在伯克利任教的愛(ài)姆茲建議一些學(xué)生對(duì)各種各樣家用產(chǎn)品進(jìn)行檢測(cè)。使他驚異的是，像用于兒童睡衣中的一種阻燃劑一樣，許多普通染發(fā)劑經(jīng)測(cè)試都呈陽(yáng)性。當(dāng)愛(ài)姆茲的測(cè)試結(jié)果導(dǎo)致對(duì)某些化學(xué)品實(shí)行新的規(guī)定和禁令時(shí)幾乎一夜之間，他就成了環(huán)保界的英雄。For the next decade public concern over carcinogens continued to rise. Then, Ames says, I started realizing something wasnt right. Too many natural substances also tested positive as carcinogens or mutagens: fruit juices, brown mustard , celery , parsley/芥末，芹菜，歐芹/ .In fact, about half of all chemicals tested by Amesboth natural and man-madeturned out to be potentially carcinogenic when given in enormous doses to rats and mice.隨后10年間，公眾對(duì)致癌物越來(lái)越關(guān)注。愛(ài)姆茲說(shuō)“于是我開(kāi)始意識(shí)到有些不對(duì)頭?！蓖瑯右脖粰z測(cè)為致癌物或致突變物而呈陽(yáng)性的天然物數(shù)量太多了：水果汁，芥菜，芹菜，歐芹等。實(shí)際上，愛(ài)姆茲測(cè)試的大約一半的化學(xué)物，當(dāng)用老鼠進(jìn)行大劑量實(shí)驗(yàn)時(shí)，無(wú)論是天然或人造的都證明有潛在的致癌作用。Ames at first assumed he had erred with his test. He hadnt. 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，愛(ài)姆茲斷定他的試驗(yàn)有問(wèn)題。他的試驗(yàn)并沒(méi)有錯(cuò)。他的錯(cuò)誤在于他象很多人一樣天真地認(rèn)為只有人造化學(xué)物質(zhì)是危險(xiǎn)的。他現(xiàn)在要問(wèn)： “為什么要推斷天然就是無(wú)害的呢?”The campaign supporting Californias 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. Its just playing with peoples fears. You can always find a part per billion of something in the water.支持加州65號(hào)提案的運(yùn)動(dòng)使愛(ài)姆茲確信他有義務(wù)向公眾解釋這一點(diǎn)。“當(dāng)人們說(shuō)某些先天缺陷是由水中十億分之一的某物質(zhì)引起時(shí)，我認(rèn)為那是不負(fù)責(zé)任的?！彼f(shuō)， “那是拿人們的害怕心理開(kāi)玩笑。你總能在水中找到十億分之一的某種物質(zhì)?！盜n testimony/witness/ before a California senate committee, Ames noted that tap water, for instance, contains the carcinogen chloroform/CHCl3/ 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.在加州參議院委員會(huì)作證時(shí)，愛(ài)姆茲舉出丁一個(gè)例子：由于用氯消毒，自來(lái)水含有致癌物氯仿大約十億分之八十三?？Х群袃煞N天然致癌物，每一種都是大約十億分之四千，而由于正常的新陳代謝，人血平均含有甲醛十億分之三干。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.有些人想當(dāng)然地認(rèn)為愛(ài)姆茲是化學(xué)工業(yè)的代言人。情況卻并非如此。他不為化學(xué)公司、藥品公司、食品公司或法律事務(wù)所提供咨詢。他沒(méi)有接受來(lái)自商界的任何好處。Environmentalists reject Amess 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 hes right. But we dont have to make a choice. 環(huán)境保護(hù)論者反對(duì)愛(ài)姆茲的觀點(diǎn)。他們說(shuō)，我們有義務(wù)在總量上使人們盡可能少地接觸致癌物。“不知為什么他認(rèn)為要進(jìn)行選擇?！狈鍘n俱樂(lè)部的卡爾波普這樣說(shuō)： “如果我們不得不在飲用水中的TCE(一種可疑的致癌溶劑)和有關(guān)吸煙的公共教育之間進(jìn)行選擇的話，可能他是對(duì)的。但是我們不是非去選擇不可?！盇mess reply:You dont 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.愛(ài)姆茲的回答是， “你不想讓每家化學(xué)公司從后門倒掉自己的垃圾，但是你生活在現(xiàn)代工業(yè)社會(huì)的代價(jià)就是水里會(huì)有十億分之幾的化學(xué)物質(zhì)。你能除去它，但花費(fèi)巨大。如果你把你所有的時(shí)間都花在追查微不足道的東西上，你就會(huì)看不到重要的危險(xiǎn)?！盨upplementary ReadingMystery - and Maybe Danger - in the AirCan electricity cause cancer? In a society that literally runs on electric power, the very idea seems preposterous/joking/. 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/ a cancer of the blood or bone marrow characterized by an abnormal proliferation of white blood cells / and other malignancies/cancer/. 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/comply with law/.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/scared,afraid/ - 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/filter/ 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/influence/ 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/電離輻射/ 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/copy, double repeat/, most scie