Long or short-term mobile phone use is not associated with increased risk of cancer, a major study has found.
Children are advised not to use mobile phones unless necessary
Mobile phone antennas emit electromagnetic fields that can penetrate the human brain.
But a Danish team found no evidence that this was linked to an increased risk of tumours in the head or neck as had been feared.
The study, of more than 420,000 mobile phone users, appears in the Journal of the National Cancer Institute.
The researchers, from the Danish Institute of Cancer Epidemiology in Copenhagen, looked at data on people who had been using mobile phones from as far back as 1982.
More than 56,000 had been using a mobile phone for at least 10 years.
They found no evidence to suggest users had a higher risk of tumours in the brain, eye, or salivary gland, or leukaemia.
Professor Tricia McKinney, Centre for Epidemiology and Biostatistics, University of Leeds, said: "The results of this Danish cohort study are important as they have analysed data from mobile phone company records and do not rely on users remembering for up to 10 years in the past how often they used their phone.
"The large numbers of subscribers in 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."
The study follows a report published earlier this year by the Institute of Cancer Research, which concluded that mobile phone use was not associated with a greater risk of brain cancer.
An independent group for the UK government, led by Sir William Stewart, that looked into the safety of mobile phones in the late 1990s also concluded mobile phones did not appear to harm health.
However, expert advice is still to limit mobile phone use among young people as a precautionary measure, as their head and nervous systems may still be developing.
And the government currently advises mobile phone users to keep their call times short.
There are more than one billion mobile phone users worldwide.