Talking for too long on a mobile phone every day, half an hour or more, could increase the risk of brain cancer. However, a flawed study on cellphone use and brain cancer conducted by World Health Organisation has found no clear link between the two, if used moderately.
WHO’s Interphone report, published in the ‘International Journal of Epidemiology’ this week, said heavy users were more at risk of developing glioma tumours who reported phone use on the same side of the head. A survey of almost 13,000 people between 2000 and 2004 found most mobile phone users did not have an increased risk of developing meningioma — a common and frequently benign tumour — or glioma, a rarer but deadlier form of cancer.
“There were, however, suggestions that using mobile phones for more than 30 minutes each day could increase the risk of glioma. Longer call times appeared to pose a greater risk than the number of calls made,” the report said.
The shortcoming of the study, however, is that majority of the subjects in it were not heavy mobile users by today’s standards. The median lifetime cumulative call time was around 100 hours with a median of 2 hours of reported use per month. The cut-off for the heaviest 10% of users is 1,640 hours corresponding to half an hour a day. Also, no victims interviewed in the 13 countries were under 30 years while many young people use mobiles for an hour or more every day.
Dr Christopher Wild, director of WHO’s cell phone study centre, said, “An increased risk of brain cancer is not established from the data from Interphone. However, observations at the highest level of cumulitive call time and the changing patters of mobile phone use since the period studied by Interphone, particularly in young people, mean that further investigation of mobile phone use and brain cancer risk is merited.”
According to Jack Siemiatycki, a professor at the University of Montreal, the findings of the Interphone study are “ambiguous, surprising and puzzling”. “If we combine all users and compare them with non-users, the Interphone study found no increase in brain cancer among users. In fact, surprisingly, we found that when we combine users independently of the amount of use, they had lower brain cancer risks than non-users,” Dr Siemiatycki said. “However, the study also found heavy users of cell phones appeared to be at a higher risk of brain tumours than non-users,” he added.
At present, India has 391 million cell phone users. By the end of 2010, this figure is estimated to rise to 500 million. The health ministry says talking for too long on a cell phone could be seriously affecting your health. Quoting a small-scale PGI Chandigarh study, health minister Ghulam Nabi Azad had said that sensorineural deafness could occur in 30% of people using mobile phones for more than two hours a day over a two-year period.