Five European countries have signed up to the biggest study to date into the effects of mobile phone usage on long-term health. The aim is to track at least a quarter of a million of people in five European countries for up to 30 years.

The Cohort Study on Mobile Communications (COSMOS) is different from previous attempts to examine links between mobile phone use and diseases such as cancer and neurological disorders in that it will follow users' behaviour in real time. So far the previous studies have asked people already suffering from cancer or other diseases about their previous mobile phone use. The studies have also been short term.

About five billion mobile phones are in use worldwide. To date, groups such as the World Health Organization, the American Cancer Society and the National Institutes of Health have found no evidence that mobile phone use harms health.

"The COSMOS study will be looking at long-term use, 10, 20 or 30 years. And with long-term monitoring there will be time for diseases to develop," he said.
The COSMOS study forms part of the Mobile Telecommunications and Health Research Program (MTHR), a UK body funded by a variety of government and industry sources and run by independent experts, mostly university academics.

Professor Lawrie Challis from MTHR said: "Many cancers take 10, 15 years for the symptoms to appear. So we've got to address the question: Could there be something out there that we need to look at?"