手机信号对儿童的影响
Children should avoid using mobile phones for all but essential calls because of possible health effects on young brains. This is one of the expected conclusions of an official government report to be published this week. The report is expected to call for the mobile phone industry to refrain from promoting phone use by children, and to start labeling phones with data on the amount of radiation they emit.
The Independent Expert Group on Mobile Phones, chaired by former government chief scientist William Stewart, has spent eight months reviewing existing scientific evidence on all aspects of the health effects of using mobile phones. Its report is believed to conclude that because we don't fully understand the nonthermal effects of radiation on human tissue, the government should adopt a precautionary approach, particularly in relation to children.
There is currently no evidence that mobile phones harm users or people living near transmitter masts.But some studies show that cell-phones operating at radiation levels within current safety limits do have some sort of biological effect on the brain.
John Tattersall, a researcher on the health effects of radiation at the Defense Evaluation and Research Agency' s site at Porton Down, agrees that it might be wise to limit phone use by children. "If you have a developing nervous system, it's known to be more susceptible to environmental insults," he says, "so if phones did prove to be hazardous-which they haven't yet-it would be sensible.
In 1998, Tattersall showed that radiation levels similar to those emitted by mobile phones could alter signals from brain cells in slices of rat brain, "what we' ve found is an effect, but we don't know if it' s hazardous," he says.
Alan Preece of the University of Bristol, who found last year that microwaves increase reaction times in test subjects, agreed that children's exposure would be greater. " There' s a lot less tissue in the way, and the skill is thinner, so children' s heads are considerably closer, " he says.
Stewart' s report is likely to recommend that the current British safety standards on energy emissions from cell-phones should be cut to the level recommended by the International Commission on Non-lonizing Radiation Protection. which is one-fifth of the current British limit. " The extra safety factor of five is somewhat arbitrary," says Michael Clark of the National Radiological Protection Board. "But we accept that it' s difficult for the UK to have different standards from an international body.
重点词汇汇总：
expected conclusions 预期的结论
refrain/rɪˈfreɪn/vi. 节制，克制；避免；制止n. 叠句，副歌；重复
label /ˈleɪbl/v. 贴标签于；把……归类，给……扣帽子；用示踪剂使（物质等）示踪n. 标签；商标；绰号；唱片公司；词目标注；
radiation /ˌreɪdiˈeɪʃn/n. 辐射；放射物
Independent Expert Group独立专家小组
chair /tʃer/n. 椅子；讲座；（会议的）主席位；大学教授的职位vt. 担任（会议的）主席；使…入座；使就任要职
nonthermal effects非热能的效应
/'nɔn'θə:məl/adj. 非热能的
adopt a precautionary approach采取预防措施
precautionary /prɪˈkɔːʃəneri/adj. 预防的；留心的；预先警戒的
transmitter masts发射机桅杆
/mæst/n. 桅杆；柱；橡树果实
hazardous /ˈhæzərdəs/adj. 有危险的；冒险的；碰运气的
in slices of rat brain在老鼠大脑的切片上
one-fifth of 五分之一的
somewhat /ˈsʌmwʌt/adv. 有点，稍微pron. 某物；几分
arbitrary /ˈɑːrbɪtreri/adj. [数] 任意的；武断的；专制的
international body.国际机构
百度翻译：
除了必要的通话外，孩子们应该避免使用手机，因为这可能会对孩子的大脑健康造成影响。这是将于本周发布的一份官方政府报告的预期结论之一。该报告预计将呼吁手机行业停止推广儿童使用手机，并开始在手机上标注其辐射量的数据。
由前政府首席科学家威廉·斯图尔特领导的移动电话独立专家小组，花了8个月的时间审查使用移动电话对健康影响的各个方面的现有科学证据。据信，该报告得出的结论是，由于我们还没有完全了解辐射对人体组织的非热效应，政府应该采取预防措施，尤其是对儿童。
目前没有证据表明移动电话对用户或住在发射塔附近的人造成伤害。但一些研究表明，手机在当前安全范围内的辐射水平下运行，确实会对大脑产生某种生物效应
国防评估和研究机构Porton Down的研究辐射对健康影响的研究员John Tattersall同意限制儿童使用手机可能是明智的。他说:“如果你的神经系统正在发育，那么你就更容易受到环境的影响。因此，如果手机确实有危险——虽然他们还没有——那么这将是明智的。”
1998年，塔特萨尔的研究表明，类似于手机发出的辐射水平可以改变大鼠大脑切片中的脑细胞发出的信号。他说:“我们发现了一种效应，但我们不知道这种效应是否有害。”
布里斯托尔大学的alan Preece去年发现微波会增加实验对象的反应时间，他也同意儿童接触微波的时间会更多。他说:“这里的组织要少得多，技能也要薄得多，所以孩子们的头要近得多。”
斯图尔特的报告很可能会建议将目前英国关于手机能源排放的安全标准降低到国际非隔离辐射保护委员会所建议的水平。这是英国现行上限的五分之一。美国国家辐射防护委员会的迈克尔·克拉克说:“把安全系数提高到5有点武断。”“但我们承认，英国很难制定与国际机构不同的标准。