英语原文

The claim: Cell phones cause brain cancer.

One Swedish study published last year found a link between long-term use of the older analog cell phones and brain cancer; research in rats has shown a link between cell-phone radiation and potentially cancer-causing DNA damage.

The counterclaim: Cell phones are safe.

The largest study to date, published last February in the Journal of the national Cancer Institute, surveyed 420,000 cell-phone users from 1992 and 20055 and concluded there was no evidence of a brain-cancer link. Two smaller studies, published last December in the Journal of the American medical Association and the New England Journal of Medicine, came to similar conclusions.

Expert analysis:

Cancer experts feel that cell phones are safe for short-term use--but note that more long-term research is needed. "Studies show that using cell phones for ten or fifteen years doesn't seem to increase brain cancer risk, but we don't have any research that goes beyond that," says Gansler. He points out that the analog phones in the Swedish study emit much more radiation than today's digital ones. And as for laboratory studies, " Results are much different in a test tube or a rat than they are in humans," he adds. But other experts are more cautious. "Brain tumors grow slowly and may not be detected for more than a decade," warns Henry Lai, Ph.D., professor of bioengineering at the University of Washington, in Seattle.

The bottom line:

Until 20-or 30-year studies are available to demonstrate cell-phone safety, take some precautions. Start with a hands-free headset, which may minimize exposure to radiation. Keep your phone away from your body when you're not using it. Joshua Muscat, Ph.D., of the American Health Foundation in Valhalla, New York, also recommends using the newer digital phones, which have less radiation than analog. Don't use it when signal strength is poor, since that means the phone has to work harder, causing it to emit more radiation. And keep your kids off cell phones, since researchers don't know how radiation affects a developing brain. As for devices that claim to protect against radiation," There's no evidence that they work," says Muscat.

中文翻译

正方：使用手机导致脑癌。

去年，瑞典公布的一项研究结果表明长期使用老式模拟手机与患脑癌有关系。对老鼠进行的研究发现，手机辐射可能破坏DNA(脱氧核糖核酸)，从而致癌。

反方：使用手机是安全的。

去年2月《国立癌症研究所杂志》公布了一项迄今为止规模最大的研究结果——该项研究调查了42万人，他们分别从1992年和2005年开始使用手机，结论是没有证据表明脑癌跟使用手机有关。去年12月《美国医学协会学报》和《新英格兰医学杂志》公布的两项规模稍小的研究结果，都得出了类似的结论。

专家分析

癌症专家认为短期使用手机是安全的；但特别指出对于长期使用手机，还需更多的研究结果以确定其安全与否。甘斯勒说：“研究表明使用手机10到15年似乎不会增加患癌症的机率，但超过那个期限我们没有任何研究结果。”他指出，瑞典那项研究中使用的模拟手机，较今天的数字手机辐射要强。甘斯勒补充说：“试管内或老鼠实验的结果跟在人体上的结果大相径庭。”但其他专家则更为谨慎一些。西雅图市华盛顿大学的生物工程学教授亨利·拉伊博士警告说：“脑肿瘤发展缓慢，十几年内可能查不出来。”

底线

要证明使用手机的安全性，需要20或30年的研究才能作出定论，因而有必要采取一些预防措施。使用无需手持的耳机能使接触辐射量降至最低。手机不用时，将它放到远离身体的地方。纽约凡尔海拉美国保健基金会的乔舒亚·米斯卡博士还建议使用新式的数字手机，它比模拟手机的辐射量要少。手机信号弱时别用，因为那意味着手机工作起来费力，因而会放出更多的辐射。让孩子远离手机，因为研究人员还不能确定手机辐射对孩子发育中的大脑有何影响。对于那些宣称能保护人体免遭辐射的装备，米斯卡认为：“没有证据表明它们能起什么作用。