There is no link between long-term use of cell phones and tumors of the brain or central nervous system, according to new research published online in the British Medical Journal in October, 2011. In what is described as the largest study on the subject to date, Danish researchers found no evidence that the risk of brain tumors was raised among 358,403 mobile phone subscribers over an 18-year period.
The number of people using mobile phones is constantly rising with more than five billion subscriptions worldwide in 2010. This has led to concerns about potential adverse health effects, particularly tumors of the central nervous system.
The International Agency for Research on Cancer (IARC) recently classified radio frequency electromagnetic fields, as emitted by mobile phones, as possibly carcinogenic to humans. But previous studies on a possible link between phone use and tumors have been inconclusive particularly on long-term use of mobile phones.
The new Danish study found that cancer rates were almost the same in both long-term users and non-subscribers of mobile phones. Researchers compared 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 tumors or any cancer among mobile phone subscribers.
Researchers led by the Institute of Cancer Epidemiology in Copenhagen, continued this study up to 2007.
The researchers concluded:
The extended follow-up allowed us to investigate effects in people who had used mobile phones for 10 years or more, and this long-term use was not associated with higher risks of cancer.
However, as a small to moderate increase in risk for subgroups of heavy users or after even longer induction periods than 10-15 years cannot be ruled out, further studies with large study populations, where the potential for misclassification of exposure and selection bias is minimized, are warranted.
In an accompanying editorial, Professors Anders Ahlbom and Maria Feychting at the Karolinska Institutet in Sweden say this new evidence is reassuring, but continued monitoring of health registers and prospective cohorts is still warranted.
Bottom line: New research suggest there is no link between long-term use of cell phones and tumors of the brain or central nervous system.