The Interphone study asserted that long-term cell phone use increases the incidence rate of certain brain tumors in the auditory region. But the same body of research also claimed that long-term use protects a person against developing other kinds of brain tumors. Because of such contradictory conclusions, researchers have headed back to the drawing board to refine the study parameters.
Another major hurdle for verifying whether cell phones pose danger is that they simply haven't been around that long. It takes anywhere from 10 to 20 years for brain tumors to develop, and a lot of people haven't owned a cell phone for that long [source: Butler]. Also, researchers have yet to accurately delineate between heavy and casual cell phone users. In comparing actual phone records against self-reported cell phone habits, the Interphone scientists found that participants underestimated the number of calls made and overestimated the duration of individual calls [source: The Economist]. Without more accurate data, study results can't be fully trusted.
With many questions left to be answered, the FDA has given cell phones a cautionary stamp of approval. The agency states that research hasn't proven any adverse health effects but also notes that it can't rule out the possibility that they may come to light in the future.
Cell phone sales indicate that the public isn't terribly concerned, either. A 2008 survey from the Centers for Disease Control and Prevention (CDC) showed that more than one in six American homes has opted for wireless over landlines [source: Blumberg and Luke].
As for Ashok Agarwal at the Cleveland Clinic, his studies on cell phones and sperm have only begun. In the meantime, if men are worried that Agarwal will prove his theory right, they don't have to ditch their mobiles. Rather, Agarwal encourages men to remove phones from their pockets while talking into mobile headsets. Speaking of headsets, experts recommend them as a way to reduce cell phone radiation exposure in general since callers don't have to hold a phone against their faces [source: Parker-Pope]. In addition, keep conversations short when reception is low, since the phone has to work harder to snag a signal.
And finally, don't believe every headline that touts the indisputable safety or danger of cell phones. It's probably going to be a while before scientists eliminate all of static obscuring the health debate over cell phones.