People who make more than 15 hours of mobile telephone calls a month are three times as likely to develop brain cancer, new research suggests.
French scientists claims that sales and business professionals are particularly at risk as they travel from meeting to meeting while communicating with clients and bosses constantly.
While most people average around two-and-a-half hours each month talking on their mobiles, busy executives can quickly reach far higher figures.
Those who clock up around 900 hours of mobile use during the course of their career are particularly prone to developing a brain tumour.
The researchers drew their conclusions from a study of 253 cases of glioma and 194 cases of meningioma reported in four French departments between 2004 and 2006.
Patients were matched against 892 healthy individuals drawn from the general population, in a bid to spot any differences between the two groups.
The comparison found a risk among those who used their phone intensively which was three times higher than those who use it far less.
The duration of use in the at risk category ranged from between two and 10 years, averaging at five years.
The Bordeaux University research, which is published in the British Occupational and Environmental Medicine journal, is the latest possible evidence of the dangers of too much mobile phone use.
It led to Priartem, a French pressure group, to call for tougher rules regulating electromagnetic waves.
Janine Le Calvez, the group’s president, told Le Parisien newspaper: ‘How much proof is needed before we launch real protective measures for the population, notably for children who start using mobiles from the age of 13?’
The World Health Organisation’s International Agency for Cancer Research has classed electromagnetic waves, including the type emitted by mobile phones, as ‘possible carcinogens.’
But Roger Salamon, of the ISPED institute which carried out the research, said: ‘There is no reason to panic. This does not mean that everyone who makes a call with a mobile phone is going to get a brain tumour.’
The study itself reads: ‘It is difficult to define a level of risk, if any, especially as mobile phone technology is constantly evolving,” the study acknowledged.
‘The rapid evolution of technology has led to a considerable increase in the use of mobile phones and a parallel decrease of [radiowave intensity] emitted by the phones.
‘Studies taking account of these recent developments and allowing the observation of potential long-term effects will be needed.’
Sources: Daily Mail