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
考研
Radiation occurs from three natural sources: radioactive material in the environment, such as in soil, rock, or building materia
Radiation occurs from three natural sources: radioactive material in the environment, such as in soil, rock, or building materia
admin
2010-09-06
34
问题
Radiation occurs from three natural sources: radioactive material in the environment, such as in soil, rock, or building materials; cosmic rays; and substances in the human body, such as radioactive potassium in bone and radioactive carbon in tissues. These natural sources account for an exposure of about 100 millirems a year for the average American.
The largest single source of man-made radiation in medical x-rays, yet most scientists agree that hazards from this source are not as great as those from weapons test fallout, since strontium-90 and carbon-14 become incorporated into the body, hence delivering radiation for an entire lifetime. (46)
The issue is, however, by no means uncontroversial; indeed, the last two decades have witnessed intensified examination and dispute about the effects of low-level radiation.
A survey conducted in Britain confirmed that an abnormally high percentage of patients suffering from arthritis of the spine who had been treated with x-rays contracted cancer. Another study revealed a high incidence of childhood cancer in cases where the mother had been given x-rays. (47)
These studies have pointed to the need to re-examine the assumption that exposure to low linear energy transfer presented only a minor risk.
Recently, examination of the death certificates of former employees of a West Coast plant which produces plutonium for nuclear weapons revealed markedly higher rates for cancers of the pancreas, lung, bone marrow and lymph systems than would have been expected in a normal population.
(48)
While the National Academy of Sciences committee attributes these differences to chemical or other environmental causes, rather than radiation, other scientists maintain that any radiation exposure, no matter how small, leads to an increase in cancer risk.
(49)
It is believed by some that a dose of one rem, if sustained over many generations, would lead to an increase of one percent in the number of 1,000 disorders per million births.
In the meantime, regulatory efforts have been disorganized, fragmented, and inconsistent, characterized by internecine strife and bureaucratic delays. A Senate report concluded that coordination of regulation among involved departments and agencies was not possible because of jurisdictional disputes and confusion. (50)
One Federal agency has been unsuccessful in its efforts to obtain sufficient funding and manpower for the enforcement of existing radiation laws, and the chairperson of a panel especially created to develop a coordinated Federal program has resigned.
选项
答案
然而,这个问题绝对是有争议的。事实上,最近20年中人们对低幅度辐射影响有了进一步的检测和争论。
解析
转载请注明原文地址:https://jikaoti.com/ti/rT7RFFFM
0
考研英语一
相关试题推荐
Innovationiskeytobusinesssurvival,andcompaniesputsubstantialresourcesintoinspiringemployeestodevelopnewideas.T
Nameshavegainedincreasingimportanceinthecompetitiveworldofhighereducation.Ascollegesstriveformarketshare,they
Theeraofcheapandconvenientsourcesofenergyiscomingtoanend.Atransitiontomoreexpensivebutlesspollutingsources
Writeanessaybasedonthefollowingtable.Inyourwriting,youshould1)describethetableand2)stateyouropinionsdrawn
Writeanessaybasedonthefollowingchart.Inyourwriting,youshould1)interpretthechart,and2)giveyourcomments.You
Writeanessaybasedonthefollowingchart.Inyourwriting,youshould1)interpretthechart,and2)giveyourcomments.You
Writeanessaybasedonthefollowingoutline.Youshouldwriteabout150wordsontheANSWERSHEET.1.Differentopinionsonsu
(Havingbeen)robbed(off)economicimportance,thosestatesare(not)likelytocountfor(verymuch)ininternationalpolitica
Theauthorbelievesthat______.Thepassageismainlyabout______.
随机试题
试述先天性白内障的治疗原则。
2%戊二醛对医疗器械浸泡消毒和灭菌的时间分别是
药物的体内代谢有哪些反应
下列各项中,属于事业单位报表的有()。
公共关系与人际关系的区别有()。
某景区利用当地著名佛教庙宇进行宗教文化资源的开发利用,取得了较好的经济效益,同时也出现了商业开发过度、管理不规范以及“僧人”摆地摊、占卦算命等问题,当地政府为此制定景区游览环境综合整治活动方案,进行整改。据此回答第问题。当地政府对该景区的综合整治,履行
根据以下资料,回答下列问题。2012年,Z省W市实现文化及相关产业增加值比上年增长9.6%。在文化产品制造业中,文化印刷、文化用品制造和工艺美术品制造三大主导行业,2012年分别实现增加值21.82亿元、11.57亿元和6.62亿元。在文化
在2010年南非举办世界杯期间,德国奥博豪森水族馆的章鱼“保罗”因“成功预测”了八场比赛的结果而名噪一时。下列关于章鱼“保罗”“成功预测”的说法,正确的有()。
KalveroObergdescribesfourstagesthatpeoplegothroughwhentheyexperiencesituationsthatareverydifferentfromthoseto
下列说法中,正确的是()。
最新回复
(
0
)