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
71
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
Thearbitrarydecisionofthefactoryownerscausedangeramongtheworkers.
Ithasbeenprovedthatthechemicalislethaltoratsbutsafeforcattle.
"Igotcancerinmyprostrate."DetectiveAndySipowiczofthefictional15’Precinct,astoic,bigbearofaman,isclearlyi
Folkwisdomholdsthattheblindcanhearbetterthanpeoplewithsight.Scientistshaveanewreasontobelieveit.Researc
Duringthepast30yearsorso,healthcarehasincreasinglybecomeaformofbusiness.Inaddition,theenvironmentsurroundin
ItissaidthatinEnglanddeathispressing,inCanadainevitableandinCaliforniaoptional.Smallwonder.Americans’lifeexp
TherearemanytheoriesaboutthebeginningofdramainancientGreece.Theonemostwidelyacceptedtodayisbasedontheassum
Stonetools,animalbonesandanincisedmammothtuskfoundinRussia’sfrigidfarnorthhaveprovidedwhatarchaeologistssayi
Theinjectionthatthegirlhadbeengivenwasbeginningtowork.Herhead【C1】______heavy,andshewasverysleepy.Oncesheope
Thebossfeltsuspiciousaboutthetruthoftheaccount,therefore,hedeterminedtogetdowntohavingagoodcheck.
随机试题
关于如何界定“裸官”,2010年发布的相关《暂行规定》明确了以下3类国家工作人员为“裸官”:配偶、子女均已移居国(境)外的;没有子女,配偶已移居国(境)外的;没有配偶,子女均已移居国(境)外的。2014年中组部下发的相关《管理办法》规定:配偶已移居国(境)
简述教育评估实施程序及其构成。
A.单加氧酶系B.ALA合酶C.糖原合酶D.己糖激酶肝细胞的线粒体内存在
患者右侧胸部被匕首刺伤半小时,有胸痛,呼吸急促,口唇发绀。脉搏130次/分,血压75/40mmHg。右侧胸壁有伤口,呼吸时能听到空气出入伤口的响声。气管移向健侧。患侧叩诊呈鼓音引起病人休克的主要原因是()
甲公司因不能清偿到期债务,被其两个债权人乙、丙向人民法院申请破产,其中乙公司对甲公司所享有的债权已过诉讼时效。法院依法受理后,指定快船律师事务所为管理人。管理人接受债权人的申报。下列四项债权均向管理人申报:①本应于1年后才到期的20万元借款;②戊公司对甲公
下列关于企业发行可转换公司债券会计处理的表述中,正确的有( )。
在苏联教育家苏霍姆林斯基任校长的学校,发生了一件事。一年级新生格里沙,由于母亲工作忙,开学第一天来上课时,耳朵没有洗干净。在第一节课上,女老师发现格里沙的耳朵很脏,就叫他站起来给大家看,把他作为典型,教育其他学生要爱清洁讲卫生。老师的这种粗心大意的做法,给
晨检中的“二摸”是指()
Onlineeducationdevelopsrapidly.Traditionaleducationwillnotbereplacedcompletely.Bothonlineandofflinelearninghave
使用不对称密钥算法进行数据加密时,公用密钥是公开的,私有密钥是保密的。发送者发送数据时,使用______来加密数据。
最新回复
(
0
)