Using a mobile phone does not increase the risk of brain cancer, claim scientists.
Research into cancer rates of one of the largest groups of mobile phone users ever studied found no difference compared with people who did not use them.
It is the second major study this year to rule out any change in rates of the disease - despite more than 70 million mobile phones being used in the UK.
The latest Danish study investigated data on more than 358,000 mobile users over 18 years, thought to be the longest follow-up so far.
But campaigners insisted the research was "seriously flawed" and would falsely reassure mobile phone users.
Researchers led by the Institute of Cancer Epidemiology in Copenhagen found cancer rates in the central nervoussystem were almost the same in both long-term mobile phone users and non-users.
They studied the whole Danish population aged over 30 and born in Denmark after 1925 by gathering information on subscribers to mobile phones from the Danish phone network operators and from the Danish Cancer Register.
They analysed data of 10,729 central nervoussystem tumours between 1990 and 2007, says a report in bmj.com (the online site of the British Medical Journal).
When the figures were restricted to people with the longest use of mobile phones - 13 years or more - the cancer rates were almost the same as that among non-subscribers.
There have been fears that cancer could be triggered by the brain's exposure to electromagnetic radiation emitted from mobile handsets held to the ear.
But the researchers said they observed no overall increased risk for tumours of the central nervoussystem or for all cancers combined in mobile phone users.
But other scientists disagree, saying the Danish study excluded business users and included as non-users people who began using mobiles later on.


据英国《每日邮报》10月21日报道，科学家声称，使用手机并不会增加罹患脑癌的风险。
对最大手机用户群体之一的癌症发病率的调查研究显示，手机用户和非手机用户之间在罹患癌症的风险上并没有什么区别。

这是今年有关排除癌症发病率影响因素的第二项重要研究--尽管在英国手机的使用者总数超过了7000万。
丹麦的这项最新研究数据来自于对超过35.8万名手机用户长达18年的调查，这也是目前为止时间最长的跟踪调查。

但是社会运动人士则坚称研究存在着"严重缺陷"，这是对手机用户的虚假承诺。
丹麦哥本哈根肿瘤流行病学协会的研究人员通过对中枢神经系统的研究发现，长期使用手机的人群与不使用手机的人群癌症发病率几乎是一样的。

他们调查了全丹麦超过30岁以及1925年后出生在丹麦的人口，通过手机网络运营商和癌症病患登记记录搜集了有关手机用户的信息。

他们分析了1990年到2007年间10729份中枢神经系统肿瘤数据，然后在bmj.com（英国医学杂志在线网站）上发表了一篇报告。

数据被限定在使用手机时间最长的用户中--13年或更久--癌症发病率与非手机用户几乎相同。

曾经人们很担忧，由于手机听筒接近耳朵，使大脑长期暴露在电磁辐射之下，有可能会引发癌症。

但研究人员说，他们并没有发现这样会增加中枢系统肿瘤发病的风险，也不会使手机用户更容易罹患其他种类的癌症。
但还有其他的科学家并不赞同这种说法，他们说丹麦的这项研究排除了商业用户，并把刚开始使用手机的人列为非手机用户。

• cancer [´kænsə] n.癌；毒瘤 (初中英语单词)
• despite [di´spait] prep.尽管 (初中英语单词)
• research [ri´sə:tʃ] n.&vi.调查；探究；研究 (初中英语单词)
• institute [´institju:t] n.学院 vt.建立；设置 (初中英语单词)
• nervous [´nə:vəs] a.神经的；神经过敏的 (初中英语单词)
• system [´sistəm] n.系统，体系，制度 (初中英语单词)
• medical [´medikəl] a.医学的；医疗的 (初中英语单词)
• studied [´stʌdid] a.故意的；有计划的 (高中英语单词)
• reassure [,ri:ə´ʃuə] vt.使放心 (高中英语单词)
• denmark [´denmɑ:k] n.丹麦 (高中英语单词)
• exposure [ik´spəuʒə] n.暴露；曝光(时间) (高中英语单词)
• saying [´seiŋ, ´sei-iŋ] n.言语；言论；格言 (高中英语单词)
• danish [´deiniʃ] a.&n.丹麦人(语)(的) (英语四级单词)
• gathering [´gæðəriŋ] n.集会，聚集 (英语四级单词)
• network [´netwə:k] n.网状物 vt.联播 (英语四级单词)
• disagree [,disə´gri:] vi.不同意 (英语六级单词)