There was reassuring news for over 1 billion mobile phone users across the globe after a study published in the Journal of the National Cancer Institute found no evidence to link mobile phone use with an increased risk of developing cancer.

In the largest and longest running investigation into the effects of mobile phone use on cancer incidence yet undertaken, researchers at the Danish Institute of Cancer Epidemiology studied 420,095 Danes who started using mobile phones between 1982 and 1995. They then tracked their health until 2002, by which time 14,249 cases of cancer had been recorded; short of the expected total of 15,001. Christopher Johansen, who led the study, concludes: “We found no evidence for an association between tumour risk and cellular telephone use among either short-term or long-term users” (http://www.timesonline.co.uk, 06 December 2006).

There were fears that the radio waves emitted by mobiles, which can penetrate up to 6 cm into the brain, might trigger head and neck cancers. Despite several previous studies that have failed to find a link between phone use and cancer, fears have persisted owing to the lack of any long-term epidemiological data. The Danish study looks to have satisfied this requirement, as Professor Tricia McKinney of the Centre for Epidemiology and Biostatistics at The University of Leeds explains: “The large number of subscribers to the study mean we can have some confidence in the results that have not linked mobile phone use to a risk of any cancer, including brain tumours” (http://www.bbc.co.uk, 06 December 2006). However, John Boice at the International Epidemiology Institute at Rockville doubts it will end the debate. “There's really no biological basis ... to be concerned about radiowaves” he said, “nevertheless people are” (http://www.thestar.com 06 December 2006).