This week the World Health Organization released a study regarding cell phone use and brain cancer risk. The Interphone study Group published the results of their research in the International Journal of Epidemiology. The researchers analyzed brain tumor, two particular forms (glioma and meningioma risk in relation to cell phone use. The interviews were conducted with over 5,000 people with brain cancer, and matched controls were evaluated in 13 countries from several previously reported studies.
The IARC (International Agency for Research on Cancer) coordinated a feasibility study in 1998 and 1999-which concluded that an international study of the relationship between cell phone use and brain tumor risk would be informative and was feasible.
The experts who evaluated approximately 13,000 cell phone users over 10 years, with the intention to determine if mobile devices cause brain tumors, said their research did not provide a definitive answer.
The researchers did acknowledge that suggestions of a possible link demanded deeper examination.
"The results really don't allow us to conclude that there is any risk associated with mobile phone use, but... it is also premature to say that there is no risk associated with it," noted the IARC's director Christopher Wild.
The results of the study have been keenly awaited by mobile phone companies and by campaign groups who have raised concerns about whether mobile phones cause brain tumors.
The most significant problem with this research is that the use of cell phones, the number of hours spent was an average of 2.5 per month. Other research studies, previously noted have determined that 1000 hours over ten years is a risk factor for developing certain brain tumors. This rate of phone usage in the period is low compared with current average cell phone utilization.
Also, the study asked people to recall and estimate their usage, which can cause inaccuracies. Perhaps a review of their cell phone bills would’ve been much more accurate.
The study began in 2000, as an international set of case-control studies in 13 countries across the globe, focusing on four brain tumors that absorb the highest amount of energy emitted by cell phones, brain glioma and meningioma, acuoustic nerve shwannoma and the parotid glad (salivary). The objective was to determine if cell phone use does increase the risk of developing these particular tumors. This is the largest case-control study of cell phone and brain tumors, thus far, and includes the largest number of cell phone users with at least 10 years of exposure.
In April European scientists last month launched what will now become the biggest ever study into the effects of mobile phone use on long-term health. It aims to track at least a quarter of a million of people in five European countries for up to 30 years.
This kind of study, called a prospective study, is considered more accurate because it does not require people to remember their cell phone use later but tracks it in real time.
Data from the IARC study showed that overall, mobile telephone users in fact had a lower risk of brain cancer than people who had never used one, but the 21 scientists who conducted the study said this finding suggested problems with the method, or inaccurate information from those who took part.
The researchers said the majority of people covered in their study "were not heavy mobile phone users by today's standards". The average lifetime cumulative call time for those who took part was around 100 hours, with an average of 2 to 2-1/2 hours of reported use a month. The heaviest 10 percent of users had clocked up an average of 1,640 hours of phone use spread over 10 years, which corresponds to about half an hour a day.
Other results showed high cumulative call time may slightly raise the risk, but again the finding was not proven reliable.
"We can't just conclude that there is no effect," said Elisabeth Cardis of the Centre for Research in Environmental Epidemiology in Barcelona, Spain, who led the study.
"There are indications of a possible increase. We're not sure that it is correct. It could be due to bias, but the indications are sufficiently strong... to be concerned."
Cell phone utilized has leaped exponentially since its introduction in the early-to-mid 1980s. About 5 billion mobile phones are currently in use worldwide.
"Today, mobile phone use has become much more prevalent and it is not unusual for young people to use mobile phones for an hour or more a day," the researchers wrote.