'No link' between cellphones and brain tumours

The largest study so far has found no evidence of a link between cellphone use and brain tumours.

UK researchers interviewed 966 people from across Britain diagnosed with brain tumours, as well as 1716 apparently healthy controls between December 2000 and February 2004.

The epidemiological survey found no evidence that using a cellphone increased the risk of developing a tumour or that prolonged usage increased risk either.

The study did find an association between the location of a tumour and side of the head that patients said they most often used to make calls. But when the team considered handedness – which correlates to the side of the head to which cellphones are most commonly held – there was no link.

In light of the overall study results the researchers believe the association was an anomaly – they suggest these patients most probably misremembered their cellphone usage, in an effort to explain the tumour.
Not for children

Several previous studies have pointed towards possible connections between cellphone usage and brain tumours. These include a Swedish study in April 2004 showing a correlation between cellphone use and auditory nerve tumours and Dutch research published in October 2003, linking cellphones to impaired brain function.

In January 2005 the UK's National Radiological Protection Board produced a report that also found no evidence to suggest cellphone use is harmful. But the NRPB recommended a "precautionary approach" and said cellphones should not be given to children under the age of 8, because they might be more susceptible than adults to any ill effects of cellphone radiation.

The new research was carried out by the Universities of Leeds, Manchester and Nottingham and the Institute of Cancer Research in the UK, with funding from the UK government and several cellphone companies. It represents part of a wider, ongoing study called Interphone, which will eventually incorporate evidence gathered from 13 different countries.
In the country

Anthony Swerdlow at the UK's Health Protection Agency, and one of the study team, cautions against drawing any absolute conclusions from the results. He adds that the relatively short time span of widespread cellphone use makes it difficult to draw strong conclusions. "There will still be some uncertainty for a long time," he says.

However, Lennart Hardell at the University of Örebro, Sweden, questions the validity of the research. In May 2005 he published the results of a study carried out in Sweden, which suggested a link between cellphone use in rural areas – where mobiles often pump out their maximum radiation – and an increased risk of developing brain cancer. "Bedside interviews are problematic with [brain tumour] patients because that can have cognitive problems," he told New Scientist.

Hardell suggests it will be at least 10 years before any firm conclusions can be drawn about the long term health risks of cellphone use.

Journal reference: British Medical Journal (early online)