Findings from a six-year research, considered the biggest ever study into mobile phone safety, found a "very slight hint" of increased cases of some type of brain tumours among people using mobiles for more than 10 years, the study says.
The Mobile Telecommunications and Health Research (MTHR) programme, however, showed no short-term harm to the brain and cells among adults from mobile phone signals or base stations, or from signals used by the emergency services.
The researchers called the results "reassuring", but stressed that further studies would be needed for the foreseeable future as mobile phone use continues to grow.
Only a small proportion of the research had included adults using mobile phones for longer than a decade, usually the time needed for cancer symptoms to appear, MTHR chairman Professor Lawrie Challis said.
"We cannot rule out the possibility at this stage that cancer could appear in a few years' time," he said.
"There is no way we can do that, both because the epidemiological evidence we have is not strong enough to rule it out and because most cancers cannot be detected until 10 years after whatever caused them," reported the online edition of Daily Mail.