'No link' between using mobile phones and brain tumours

In collaboration with the Press Association

There is no link between using a mobile phone and developing tumours in the brain or central nervous system, according to a Danish study published in the British Medical Journal today.

Experts from the Institute of Cancer Epidemiology in Copenhagen found there was no difference in the rates of brain or central nervous system tumours in long-term mobile phone users compared with those who do not use them at all.

There were concerns that electromagnetic fields emitted by holding a headset near to the ear could harm the health of five billion mobile phone users worldwide.

But this new research, which studied over 350,000 mobile phone subscribers and compared them with the remainder of people over 30 who were born in Denmark after 1925, found no overall rise in risk for developing tumours in the brain or central nervous system. The study used mobile phone subscriptions as a way to indirectly measure mobile phone use.

There was also no increased risk of developing other types of cancers among long-term mobile phone subscribers.

The authors said: "The extended follow-up allowed us to investigate effects in people who had used mobile phones for 10 years or more, and this long-term use was not associated with higher risks of cancer.

"However, as a small to moderate increase in risk for subgroups of heavy users or after even longer induction periods than 10-15 years cannot be ruled out, further studies with large study populations, where the potential for misclassification of exposure and selection bias is minimised, are warranted."

In an editorial accompanying the research, Professors Anders Ahlborn and Maria Feychting, of Sweden's Karolinska Institutet described the findings as reassuring but urged continued monitoring of health registers.

Danish experts analysed data of 10,729 tumours between 1990 and 2007 and gathered information from Danish phone network operators and the Danish Cancer Register for the study.

Hazel Nunn, head of evidence and health information at Cancer Research UK, said: "These results are the strongest evidence yet that using a mobile phone does not seem to increase the risk of cancers of the brain or central nervous system in adults. The study minimised many of the problems of previous research in this area and included over 350,000 Danish mobile phone subscribers, many of whom had used mobile phones for longer than 10 years.

"Even longer term follow up of cancer risk in mobile phone users is still needed, as are studies of effects of mobile phone use in children."

Copyright Press Association 2011

References

Frei, P. et al. Use of mobile phones and risk of brain tumours: update of Danish cohort study. BMJ 2011;343:d6387 doi: 10.1136/bmj.d6387