NEW DELHI: Talking for too long on a mobile phone every day, half an hour or
more, could increase the risk of brain cancer. However, a 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.