U.S. researchers found "clear evidence" that cellphone radiation exposure can cause cancerous heart tumors in male rats.
美国研究人员发现，有“确凿证据”显示，手机辐射能引发雄性大鼠罹患恶性心脏肿瘤。

It is still unclear what the final conclusions of their two-decades-long study of the health impact on rodents mean for humans.
他们在对啮齿动物的健康所受的影响进行了长达20年的研究后得出了这一最终结论，目前尚不清楚该结论对人类而言意味着什么。

Some evidence of links to brain and adrenal gland tumors was also found in male rats, but in female rodents and male mice signs of cancer weren't clear, the National Toxicology Program (NTP) concluded in its final report.
根据美国国家毒理学计划在其最终报告中得出的结论，研究中还发现了雄性大鼠罹患脑癌和肾上腺癌与辐射有关的一些证据，但在雌性大鼠和雄性小鼠中，辐射致癌的证据并不明确。

The program is run by the US Department of Health and Human Services and was tasked with reviewing the toxicity of mobile phone radiation in response to the devices' near ubiquity in modern life.
这一项目由美国卫生与公众服务部管理，其任务是在现代生活人人离不开手机的背景下审视手机辐射的毒性。

Radiation exposure in the trial was well above the levels most humans would experience, but researchers said the findings show the link between radio frequencies and tumours -- at least for rats -- "is real".
试验中的辐射水平远远超过了大多数人所能体验到的水平，但研究人员表示，这些发现表明，至少对老鼠来说，无线电频率辐射与肿瘤之间的联系“是真实存在的”。

"The exposures used in the studies cannot be compared directly to the exposure that humans experience when using a cell phone," said Dr John Bucher, a senior scientist at the NTP.
美国国家毒理学计划高级科学家约翰·布赫博士表示：“研究中使用的辐射暴露不能直接与人类使用手机时所产生的相比较。”

"In our studies, rats and mice received radio frequency radiation across their whole bodies. By contrast, people are mostly exposed in specific local tissues close to where they hold the phone. In addition, the exposure levels and durations in our studies were greater than what people experience."
“在我们的研究中，大鼠和小鼠的全身都受到了射频幅射。相比之下，人类大多数只是局部组织（靠近拿手机的地方）接触到辐射。此外，与人类相比，研究中的实验动物接触的辐射水平更高、时间更长。”

But he added: "We believe that the link between radio frequency radiation and tumours in male rats is real, and the external experts agreed."
但是他补充道：“我们相信，射频幅射与雄性大鼠肿瘤之间的关联是真实存在的。外部专家对此也表示赞同。”