A significantly increased risk was found for tumours which developed on the same side of the head as the phone was reported to have been held but this was mirrored by a decrease in the risk on the opposite side of the head making it difficult to interpret as a real effect.
By BMJ, [RxPG] Mobile phones are not associated with an increased risk of the most common type of brain tumour, finds the first UK study of the relationship between mobile phone use and risk of glioma.
The four year study by the Universities of Leeds, Nottingham and Manchester and the Institute of Cancer Research, London found those who had regularly used a mobile phone were not at a greater overall risk of developing this type of tumour.
There are over 4,000 new cases of brain tumours per year of which glioma is the most common type. Early symptoms include headaches and feelings of nausea. The causes of these tumours are currently unknown.
The study was conducted between 1 December 2000 and 29 February 2004 and included people living in the Thames region, southern Scotland, Trent, the West Midlands and West Yorkshire.
There was no relationship for risk of glioma and time since first use of a mobile phone, lifetime years of use and cumulative number of calls and hours of use. Risk was not associated with phone use in rural areas which was found to be associated with an increased risk in an earlier Swedish study.
A significantly increased risk was found for tumours which developed on the same side of the head as the phone was reported to have been held but this was mirrored by a decrease in the risk on the opposite side of the head making it difficult to interpret as a real effect.
Mobile phones have been available in the UK since 1985, but widespread use did not begin until the late 1990s making the number of long term users (over 10 years) quite small. This study had limited numbers for estimating the risk of using a phone over a long period.
Early mobile phones were designed to use analogue signals and emitted higher power than current digital phones but the study showed no increased risk of glioma brain tumours with the use of analogue phones.
966 people with glioma brain tumours (cases) and 1716 healthy volunteers (controls) were interviewed about their previous mobile phone use history including how long they had used mobile phones, the number and duration of the calls they made and what make and model of phone they had used.
This finding may be due to people with glioma brain tumours linking mobile phone use to the side of the tumour and therefore over reporting the use of a phone on the same side as their tumour. This results in under reporting use on the opposite side of the head, say the authors.
