今年以来关于手机是否会致癌尤其是脑癌的问题，在科学界引发热烈讨论。而10月21日发布的一份丹麦大范围研究报告则为手机不会导致脑癌的观点提供了新证据。
新一轮讨论由国际癌症研究中心引发。今年5月，该研究中心发布报告称，长期、高强度使用手机和其他无线通信设备可能增加患癌症几率。但该结论随即受到一些无线通信行业组织质疑。今年7月，英国癌症研究所专门就此发布报告说，现有证据无法证明使用手机致癌。
丹麦癌症流行病研究所等机构的科研人员在最新一期《英国医学杂志》上报告说，他们调查了丹麦所有1925年以后出生、年龄在30岁以上人群的资料，根据手机运营商的签约信息，他们被分为手机签约用户和非手机签约用户两组，其中手机签约用户超过35万人。
同时，研究人员调查了1990年到2007年间丹麦脑癌患者人数，这段时间正是手机开始大量普及使用的时期。结果显示，共有1万多个脑癌病例，但对于手机签约用户和非手机签约用户这两组人来说，患脑癌的比例没有明显差异。
研究人员说，这项研究的有力之处在于它覆盖了丹麦全国人口，样本数量足够多，结果也较为可信。但它也有不足之处，即划分两组人的标准是手机签约情况，这并不能完全反应他们如何使用手机，有些用户用手机的频繁程度会比别人高出很多，而研究中没有把这部分重度使用者区分出来。总的来说，这项研究结果支持了手机不会导致脑癌的观点。
使用手机与癌症尤其是脑癌之间有无因果关系，还需要科学界进一步研究。目前科学界和各国管理机构都强调一点，即青少年应该慎用手机。青少年的耳朵和颅骨比成年人更小、更薄，他们在使用手机时，脑部吸收的辐射据称比成年人要高出50%。（生物谷 Bioon.com）
doi:10.1136/bmj.d6387
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Use of mobile phones and risk of brain tumours: update of Danish cohort study
Patrizia Frei, postdoctoral research fellow1, Aslak H Poulsen, doctoral student1, Christoffer Johansen, professor1, Jørgen H Olsen, director1, Marianne Steding-Jessen, statistician1, Joachim Schüz, head of section
Objective To investigate the risk of tumours in the central nervous system among Danish mobile phone subscribers.
Design Nationwide cohort study.
Setting Denmark.
Participants All Danes aged ≥30 and born in Denmark after 1925, subdivided into subscribers and non-subscribers of mobile phones before 1995.
Main outcome measures Risk of tumours of the central nervous system, identified from the complete Danish Cancer Register. Sex specific incidence rate ratios estimated with log linear Poisson regression models adjusted for age, calendar period, education, and disposable income.
Results 358 403 subscription holders accrued 3.8 million person years. In the follow-up period 1990-2007, there were 10 729 cases of tumours of the central nervous system. The risk of such tumours was close to unity for both men and women. When restricted to individuals with the longest mobile phone use—that is, ≥13 years of subscription—the incidence rate ratio was 1.03 (95% confidence interval 0.83 to 1.27) in men and 0.91 (0.41 to 2.04) in women. Among those with subscriptions of ≥10 years, ratios were 1.04 (0.85 to 1.26) in men and 1.04 (0.56 to 1.95) in women for glioma and 0.90 (0.57 to 1.42) in men and 0.93 (0.46 to 1.87) in women for meningioma. There was no indication of dose-response relation either by years since first subscription for a mobile phone or by anatomical location of the tumour—that is, in regions of the brain closest to where the handset is usually held to the head.
Conclusions In this update of a large nationwide cohort study of mobile phone use, there were no increased risks of tumours of the central nervous system, providing little evidence for a causal association.
