Research suggests mobile phone usage for more than a decade greatly increases the risk of cancer. The study found that long-term users – and the phones have become a required tool for many workers – had double the chance of getting a malignant tumour on the side of the brain where they held the handset.

Lennart Hardell and others. Long-term use of cellular phones and brain tumours: increased risk associated with use for equal to or greater than 10 years, Occupational and Environmental Medicine, volume 64, pages 626-632, 2007 [abstract].