首页
登录
职称英语
Can electricity cause cancer? In a society that literally runs on electric
Can electricity cause cancer? In a society that literally runs on electric
游客
2023-11-20
20
管理
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 long wave-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 kilovolts per meter, but the corresponding field induced in human cells will be only about I 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 for 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. [br] The view-point of the EPA is ______.
选项
A、there is casual link between electricity and cancer
B、electricity really affects cancer
C、controversial
D、low frequency electromagnetic field is a possible cause of cancer
答案
A
解析
细节理解题。答案在第二段第三句,环保署目前的结论是科学证据指出极低频电磁场——具有长波的电磁场——和白血病,淋巴瘤及脑癌之间有着难以确定的联系,从而说明电和致癌有一定的难以确定的关系。
转载请注明原文地址:https://tihaiku.com/zcyy/3204211.html
相关试题推荐
Bytheyear2010,scientistsprobably______aneffectivetreatmentforcancer.A
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
Inoursociety,wemustcommunicatewithpeople.Agreatdealofcommunicat
随机试题
WecandiscussTaiwanquestion____________(在一国两制的基础上).onthebasisof"Onecou
Imeant(buy)______aneveningpaperformydadbutIdidn’tseeanyonesellingth
Mostpeopleareawarethatoutdoorairpollutioncandamagetheirhealth,bu
Adecadeago,theideathattheplanetwaswarmingupasaresultofhumana
染色体核型分析的指征不包括()A.疑有染色体病者 B.发现有多种先天性畸形
人体运动后,为保持体内酸碱平衡,应多吃()。A.米饭 B.苹果
关于开放式基金和封闭式基金说法不正确的是()。A:封闭式基金的份额数量是随时变化
药物相互作用发生的意外事件确切地说应该称之为A.残存效应 B.后遗效应 C.
2012年,某啤酒公司因产品标识问题受到当地质量技术监督局的处罚。公司领导认识
药物相互作用有发生在体内的药动学、药效学方面的作用;亦有发生在体外的配伍变化,如
最新回复
(
0
)