An international study, led in the UK by researchers at the University of Leeds and the Institute of Cancer Research (ICR), has shown no link between mobile phone use and brain tumours.
It is the largest epidemiological study of mobile phone use to date.
Increasing mobile phone use has led to public concern about possible cancer risks. Interphone, an interview-based, case-control study of mobile phone use, was conducted to address these concerns.
The paper published today in the International Journal of Epidemiology combines information from all 13 countries that took part in the study and focuses on the two main types of brain tumour, glioma and meningioma.
Professor Patricia McKinney, epidemiologist at the University of Leeds and leader of the UK North part of Interphone, said "Overall this research has not shown evidence of an increased risk of developing a glioma or meningioma brain tumour as a result of using a mobile phone. This is consistent with published biological studies, which have not established any effect of exposure to radiation from mobile phones at a cellular level nor found a mechanism by which cancer could be caused".
Interphone was conducted between 2000 and 2004 and was coordinated by the International Agency for Research on Cancer (IARC). The work was carried out in 13 countries, with much the largest contribution coming from the UK. Results from individual countries, including the UK, have been published previously but this is the first time that data from all 13 countries has been analysed together.
A total of 2708 men and women aged 30-59 years with glioma and 2409 with meningioma, and matched adult controls without a brain tumour, were interviewed about their mobile phone use. Participants were asked about when they started using a mobile phone, how many times per day they used their phone, and how long the calls were.
The study found no overall increase in risk of glioma or meningioma brain tumours in regular users of mobile phones. Indeed regular users had an apparently decreased risk, although this decrease seems likely to be an artefact of the study methods and not a real effect from using a mobile phone. No relationship was found between the risk of a tumour and the number of years people had been using mobile phones; risks were not raised for people who had used mobile phones for the longest category analysed - 10 or more years.
For the estimated total (cumulative) hours of phone use there was an apparently increased risk of glioma seen in the highest ten percent of users. However, some of these had reported improbable levels of use, for instance 12 or more hours every day; there was no trend of increasing risk with greater phone use for people in the nine lower use categories; and there was no relation to risk for the cumulative number of phone calls made. These factors suggest that the apparently increased risk with the highest cumulative hours of use cannot be interpreted as evidence of mobile phones causing brain tumours.
Subjects were asked the side on which they had used a phone, but no conclusion about brain tumour causation could be drawn from this because their recollection and reporting of the side of use may well have been biased by their knowledge of the side that their tumour occurred.
Professor Anthony Swerdlow, epidemiologist at The Institute of Cancer Research and leader of the UK South part of the Interphone project, said "Interphone is by far the largest study of its type to date. The balance of evidence from this study, and in the previously existing scientific literature, does not suggest a causal link between mobile phone use and risk of brain tumours. The duration of phone use for which we yet have evidence is currently limited, however, and we have virtually no information for use of mobile phones for longer than 15 years."
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Notes for editors
In addition, the northern UK study received funding from the Health and Safety Executive, the Department of Health, the UK network Operators (O2, Orange, T-Mobile, Vodaphone) and the Scottish Executive. The funding from the mobile phone operators to the University of Leeds was received under legal signed contractual agreement which ensured the complete independence of the investigators.