Danish scientists have claimed that prolonged usage of mobile phones is not linked with the risk of brain tumours and have clearly contradicted many of the studies on the same subject published earlier.
In what is described as the largest study on the subject till date, Danish researchers found no evidence that the risk of brain tumours was raised among 358,403 mobile phone subscribers over an 18-year period.
The number of people using mobile phones is on a constant rise with more than five billion subscriptions worldwide in 2010. This has led to concerns about potential adverse health effects, particularly tumours of the central nervous system.
Previous studies on a possible link between phone use and tumours have been open to doubt, particularly the ones which deal with long-term use of mobile phones.
The only cohort study investigating mobile phone use and cancer to date is a Danish nationwide study comparing cancer risk of all 420,095 Danish mobile phone subscribers from 1982 until 1995, with the corresponding risk in the rest of the adult population with follow-up to 1996 and then 2002.
This study found no evidence of any increased risk of brain or nervous system tumours or any cancer among mobile phone subscribers.
So researchers, led by the Institute of Cancer Epidemiology in Copenhagen, continued this study up to 2007. They studied data on the whole Danish population aged 30 and over and born in Denmark after 1925.
Information was collected from the Danish phone network operators and from the Danish Cancer Register. Overall, 10,729 central nervous system tumours occurred in the study period 1990-2007.
When the figures were restricted to people with the longest mobile phone use - 13 years or more - cancer rates were almost the same in both long-term users and non-subscribers of mobile phones.