Will using a mobile phone really cause brain cancer?

New research suggests that using a phone increases your risk of cancer, but the numbers tell a different story.

Ever since the Stewart report into mobile phone safety was published in 2000, many parents have been nervous about their children's fondness for fashionable handsets. While this expert inquiry found no evidence of harm, it recommended a precautionary approach for children, citing uncertainties about their developing brains.

Those fears have been heightened this week by a spate of alarming headlines, triggered by a story in the Independent on Sunday. “Children and teenagers are five times more likely to get brain cancer if they use mobile phones,” it declared.

A study by Lennart Hardell, a Swedish scientist, had found an increased risk of two types of tumour, acoustic neuroma and glioma, among under-16s who used mobile phones. Here, it appeared, was evidence that concern was justified. The story, however, was not quite what it seemed. In fact, it is an object lesson in how not to report risk.

A five-fold risk sounds extremely frightening. But it is what is known in statistics as a relative risk, and on its own, it is meaningless for judging health hazards. The question you need to ask is: “Five times what?” If the original risk is reasonably high, a five-fold rise might be worth worrying about, but a tiny risk multiplied five times will still be tiny. It is absolute risks - the overall chance of getting a condition - that matter for health. The Independent on Sunday did not supply them.

Source - Times

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