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
2024-10-26
29
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] Why did the Pentagon and White House object to the release of the report?
选项
A、Because it may stir a great deal of debate among the Bush Administration.
B、Bemuse every unit of the modern military has depended on the heavy use of some kind of electronic equipment.
C、Bemuse the Pentagon’s concern was understandable.
D、Because they had different arguments.
答案
B
解析
推理题。五角大楼和白宫之所以反对环保署公布报告的理由就在于此。空军方面的专家之所以说环保署方面的报告“歪曲了整个文件以证明两者之间的关系”也在此。所以文内说“五角大楼的关注是可以理解的。”
转载请注明原文地址:https://tihaiku.com/zcyy/3818774.html
相关试题推荐
Thesedayswehearalotofnonsenseaboutthe"greatclasslesssociety".T
Thesedayswehearalotofnonsenseaboutthe"greatclasslesssociety".T
Thesedayswehearalotofnonsenseaboutthe"greatclasslesssociety".T
Whatisthetalk’mainlyabout?[br][originaltext]Areelectriccarsthew
Whatisthetalk’mainlyabout?[br][originaltext]Areelectriccarsthew
Everysocietyhasitsownpeculiarcustomsand______ofacting.A、waysB、behavio
Canelectricitycausecancer?Inasocietythatliterallyrunsonelectric
Canelectricitycausecancer?Inasocietythatliterallyrunsonelectric
Canelectricitycausecancer?Inasocietythatliterallyrunsonelectric
Histechniquehasdevelopedtothepoint______hecanrepairmanyoftheelectric
随机试题
TheOriginofMoneyIntheearlieststagesofman’sd
Peopleinsunny,outdoorsystates—Louisiana,Hawaii,Florida—saytheyareth
下列属于营养改善项目的是( )。A.分析营养问题 B.确定项目目标 C.执
医疗事故的预防
与一般财务审计以验证企业财务报表真实性为目的不同,财务尽职调查强调发现企业的潜在
建设单位应当将大型的人员密集场所和其他特殊建筑工程的消防设计文件报送公安机关消防
对下列哪些选项中的情况,行政机关应当举行听证?()A.某市因城市建设需将一
以下有关解热镇痛药用于镇痛的健康提示中,正确的是A.对钝痛有较好的镇痛效果 B
根据物权法律制度的规定,以下列权利出质时,质权可以自权利凭证交付时设立的是()
(2020年真题)根据《环境影响评价技术导则地表水环境》,确定水文要素影响型建设
最新回复
(
0
)