首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
医学
Can electricity cause cancer? In a society that literally runs on electric power, the very idea seems preposterous. But for more
Can electricity cause cancer? In a society that literally runs on electric power, the very idea seems preposterous. But for more
admin
2013-12-06
70
问题
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 micro-wave 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—or the worst kind of paranoia.
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 casual link" between extremely low-frequency electromagnetic fields — those having very longwave-lengths — 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 lost 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. But now no one can deny that the issue must be taken seriously and that much more research is needed.
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. The ELF magnetic field generated by a video terminal measures only a few milligauss, or about one-hundredth the strength of the earth’s own magnetic field. The electric fields surrounding a power line can be as high as 10 kilo volts per meter, but the corresponding field induced in human cells will be only about 1 millivolt per meter. This is far less than the electric fields that the cells themselves generate.
How could such minuscule forces pose a health danger? The consensus used to be that they could not, and for decades scientists concentrated on more powerful kinds of radiation, like X-rays, that pack sufficient wallop to knock electrons out of the molecules that make up the human body. Such "ionizing" radiations have been clearly linked to increased cancer risks and there are regulations to control emissions.
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 biological effects on animal tissues, a mechanism by which those effects could lead to cancerous growths has never been found.
The Pentagon is far from persuaded. In a blistering 33-page critique of the EPA report, Air Force scientists charge its authors with having "biased the entire document" toward proving a link. "Our reviewers are convinced that there is no suggestion that electromagnetic fields present in the environment induce or promote cancer," the Air Force concludes. "It is astonishing that the EPA would lend its imprimatur on this report." Then Pentagon’s concern is understandable. There is hardly a unit of the modern military that does not depend on the heavy use of some kind of electronic equipment, from huge ground-based radar towers to the defense systems built into every warship and plane.
What do you think ordinary citizens may do after reading the different arguments?
选项
A、They are indifferent.
B、They are worried very much.
C、The may exercise prudent avoidance.
D、They are shocked.
答案
C
解析
因为他们不可能像A项那样漠不关心,毕竟这种问题直接影响人的生命;B.他们非常担忧;D.他们感到震惊,这两项都不可能,因为还在争议中,唯一的途径是尽量避开和电器接触。
转载请注明原文地址:https://kaotiyun.com/show/ycU3777K
本试题收录于:
医学博士外语题库考研分类
0
医学博士外语
考研
相关试题推荐
Justbeforedawnwereceivedacallthatanunresponsiveinfantwasbeingbroughtbyemergencymedicalservicestoourhospital.
Severalclassesofbittercitruscompoundhavelookedpromisingasanticanceragentsinlaboratorytests.Anewstudyindicates
Duringrushhour,Downtownstreetsare______withcommuters.
Thetruthmaywellbeself-evidentthatallhumansarecreatedequal,butonethingourMakerdidnotendowuswithequallyist
Youfeelgenerallydepressedandunabletoconcentrate.Your【C1】______ofdailyactivitymaychange;youfindyourself【C2】______a
Themostinterestingarchitecturalphenomenonofthe1970’swastheenthusiasmforrefurbishingoldbuildings.Obviously,thisw
Stonetools,animalbonesandanincisedmammothtuskfoundinRussia’sfrigidfarnorthhaveprovidedwhatarchaeologistssayi
Thegroundundertowingoaksisoftenlitteredwiththousandsofhalf-eatenacorns,eachoneonlybittenfromthetop.Whywould
Archaeologycantellusplentyabouthowhumanslookedandthewaytheylivedtensofthousandsofyearsago.Butwhataboutthe
A、Hislovelyvoice.B、HisItalianbackground.C、Hisattractiveappearance.D、Hispatiencewithpatients.D细节题。女士说让她印象最深刻的是那医生总是“
随机试题
牵涉痛是指
一分子乙酰CoA经有氧氧化(三羧酸循环)可生成几分子ATP
A.庚型肝炎病毒B.流感病毒C.戊型肝炎病毒D.水痘-带状疱疹病毒E.鼻病毒
下列哪项不属于实现区域生态安全格局的途径?()
统计对事物进行动态研究的基本方法是编制()。
某产品的销售单价为8元/件,单位边际贡献是4元/件,固定成本为10000元,目标净利润为22500元。所得税税率25%,则实现目标净利润的销售额为()。
剥夺人的快速眼动睡眠后,让其重新入睡。其快速眼动睡眠通常会
世界是物质的世界,对物质的正确理解是我们认识和把握世界本质和规律的前提。马克思主义认为物质是
Thepresidenthasevery______ofholdingameetingonaweeklybasistokeepmangersinformedoftheproject.
Shestudiesmanybooksaboutfashion,entertainingandcorrectsocialbehaviorasshewantstoappear______.
最新回复
(
0
)