英语翻译So far,no studies have proven beyond question that the r

英语翻译
So far,no studies have proven beyond question that the radio signals from cell phones cause brain cancer or other health problems.But a new study by government scientists in the United States has some people wondering what to think.
Dr.Nora Volkow led the study.She heads the National Institute on Drug Abuse,part of the National Institutes of Health.Dr.Volkow says she would not be concerned that fifty minutes of cell phone exposure would harm anyone.But she says the research does show the need to study whether or not there are long-lasting effects of repeated exposure over several years.
Her team studied forty-seven healthy volunteers between January and December of two thousand nine.The volunteers had cell phones placed against both ears while the scientists made images of their brain activity.
As part of the test,one phone was activated but muted for fifty minutes.The other phone was off.After that,the people were tested with both phones turned off.Dr.Volkow says the brain scans showed increased activity in brain cells closest to the activated phone.
The scans showed how the brain cells used sugar to produce energy,a normal activity.The activity was seven percent higher in areas of the brain closest to the cell phone antenna.
The study appeared in the Journal of the American Medical Association.
Experts say people who are concerned about mobile phones can take steps like using a hands-free device.
Dr.Giuseppe Esposito is a nuclear medicine expert at Georgetown University Medical Center in Washington.He says after many years of studies,better kinds of research are still needed to settle questions about cell phone safety.These studies would take years.

到目前为止,还没有研究已经证实毫无疑问的无线电信号从手机导致大脑癌症或其它健康问题.但一项新研究,科学家们在美国政府让一些人怀疑该想些什麽.
诺拉Volkow博士带领了这次研究.她率领国家药物滥用研究所的一部分,美国国家卫生研究院.博士说,她不会Volkow担心50分钟,手机暴露会伤害任何人.但是她说研究还显示了需要研究是否有持久的影响在好几年前的重复使用.
她的小组研究了47个健康的志愿者从1月至12月2000年的9个.志愿者们有了手机放置在两耳当科学家们为自己制造偶像他们大脑的活动.
作为部分的测试,一个电话就被激活而沉默的50分钟.其他的电话都是关着的.在那之后,人们进行了测试与两个手机关机.博士Volkow说大脑扫描显示增加了经济活动中最接近激活脑细胞的电话.
扫描显示了脑细胞用糖生产能量,一个正常的活动.这一活动,是高百分之七的大脑区域靠近手机天线.
该研究发表于《美国医学会杂志》上.
专家说那些担心手机可以采取措施像使用免提装置.
朱塞佩.弗雷患病是核医学专家在华盛顿乔治敦大学医学中心.他说,经过多年的研究,更好的种研究仍然需要解决问题的手机的安全性.这些研究需要花费数年的时间.