If there's one lifestyle tool that's ubiquitous, from American cities to remote villages of the developing world, it's the mobile phone, according to AP. Can they also be deadly? The frustratingly unresolved debate erupted again this week with the release of a $24 million U.N. study spanning a decade and covering 13 nations that suggests frequent cell phone use may increase the chances of developing rare but deadly form of brain cancer. Worryingly, since glioma has a potential latency period of a quarter century _ longer than cell phones have been in widespread use _ even the study's authors say there is no way yet to tell how big the risk is, if there is one. Experts were nearly unanimous in saying the results of the study are inconclusive. But the fact that it turned up even some evidence of a cancer risk may have profound consequences for a device that people have become accustomed to seeing as extensions of themselves. From farmers in Africa who rely on cell phones to check crop reports to hedge fund traders obsessively checking Blackberries at trendy restaurants to suburban American kids spending hours calling their friends _ people around the world have come to rely on mobile phones as never before. Cell phones send out radioactive energy in a form that's similar to the one used in microwave ovens, but at very low levels. There is no accepted theory to explain how or if these weak radio waves can affect the body, beyond heating it to a very small degree. All the same, U.S. and European regulators already limit the energy cell phones can project into the body and today's digital phones radiate less power than the analog phones that dominated in the early '90s. Common advice for those concerned about the radiation is to use a Bluetooth headset, since these emit even less power. The survey conducted from 2000 to 2010 of almost 13,000 participants _ the biggest ever of its kind _ found a 40 percent higher incidence of glioma among the top 10 percent of people who used their mobile phone most. A lesser spike of 15 percent was observed with meningioma, a more common and frequently benign tumor. Researchers ignored the time spend using handsfree devices, keeping the phone in a pocket or beside the bed at night because even a distance of 4 inches (10 centimeters) reduces the amount of radiation to the brain to almost zero. But because cell phone use has boomed during the 10-year period studied, the researchers' definition of heavy use as 30 minutes of calls or more a day is now common. «The users in the study were light users compared to today,» said Prof. Elisabeth Cardis of World Health Organization's International Agency for Research on Cancer, or IARC, which organized the study. The highest risk found was for tumors on the same side of the head as users held their phone, particularly for tumors in the temporal lobe closest to the ear, Cardis told reporters in Geneva on Monday. «This is the region of the head which receives the most exposure.» Despite this evidence pointing to a link between cell phone use and tumors, the 21 researchers involved in the study disagreed on the conclusion, in part because of flaws in the way the surveys were conducted. For example, the study appeared to show that casual users had a lower risk of getting cancer than people who didn't use cell phones at all, a result the researchers described as «implausible» and blamed on methodological problems. The message? The researchers refused to rule out that cell phone use causes brain cancer but wouldn't say it does either.
