Researchers have failed to find a conclusive link between mobile phone usage and increased brain tumour risk.

Although there is, as yet, no known biological mechanism by which mobile phones could cause cancer, an international study was set up in 2000 to look into the links.

The Interphone study, the largest of its kind, covered almost 13,000 people across 13 countries and compared frequency of exposure and mobile phone use of people with four types of brain tumours - tumours of the brain (glioma and meningioma) and of the acoustic nerve (schwannoma) and partotid gland - against healthy volunteers.

Suggested links

According to the study there were 'suggestions' of an increased risk of glioma and meningioma in heavy phone users. However, the study authors concluded these findings were 'biased' because some users reported improbable levels of use of 12 or more hours a day, and 'limited' by the study's methodology, because people with brain tumours were more likely to overestimate the role of a potential risk factor.

'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,' said Professor Anthony Swerdlow, from the Institute of Cancer Research.

Professor Swerdlow did admit that mobile phone use had increased since the start of the study period and that they had no information on the use of mobile phones for longer than 15 years. But he pointed out that radiation emissions were, on average, lower from more modern handsets.

Criticism

The report was criticised for failing to look at the risks of using hands-free devices and keeping a phone close to the body for long periods, such as in a pocket or by the bed at night. However, Professor Patricia McKinney, from Leeds University and another one of the participating scientists, said radiation from a phone in a pocket or by the bed was 'very low'.

The study also failed to look separately at children despite a recent Swedish study showing that children and teenagers using mobile phones were at an increased risk of developing a brain tumour.

However, Professor McKinney said it was wrong to 'jump on the results of single studies', and that most of the literature that have made claims about risks had not been replicated.

'Although [the study's findings are] inconclusive there is still an important message that if there had been a larger risk then this study would have found it,' concluded Professor McKinney.

Earlier this month, acknowledging the gap of evidence on mobile phone use and children, a new five-year study MobiKids was launched to investigate the risk of brain tumours amongst young people.

Useful links
Interphone study findings
MobiKids study
International Agency for Research on Cancer (IARC)

	READ MORE...
	INVESTIGATION Mobile phones and health: what do we know? Yanar Alkayat takes a timely look at what we know for certain about mobile phones and health
	NEWS French want to ban mobile phones in schools Mobile phones could soon be banned in junior schools in France, under plans put forward by French senators
	NEWS Mobile phone safe radiation guide published US agency publishes radiation ranking for top brands including Motorola, Blackberry and Apple iPhone