The thing about cell phones, and for that matter red dye and fish hatcheries, is that you have to look at the numbers.
The WHO study followed some 13,000 people for about 10 years. That group would have about 1 or 2 acoustic neuromas in that time. That makes meaningful statistics pretty hard to come by. The highest reported increase in tumors was 39% (1 out of 8 studies). If that were the true number, what would that mean? It would mean that if 1 million people gave up their cell phones for a year, they would get only 10 acoustic neuromas among them, instead of 14 of them.
An acoustic neuroma is a rare condition. It doesn't make sense for a million people to give up using cell phones so that 4 people don't get an AN. The only people who might think it makes sense are people like us, who have already gotten one. One reporter pointed out that far more people die every year because they are texting or talking on cell phones while driving. Focusing on problems that are common makes far more sense.
40% may seem like a big increase (I doubt the real number is that high), but consider that if you buy two lottery tickets instead of one, you have improved your chances of winning by 100%. Does that suddenly make it likely that you will win? No it doesn't. And using a cell phone does not suddenly make it likely that you will get a brain tumor, either. Getting an acoustic neuroma remains a very unlikely thing, no matter what you do or don't do.
Steve