Be afraid. Be very afraid. That's the message from the Swedish National Institute for Working Life, which has just completed a massive study on the cancer risks from cell phone use. Their results, which appear in the International Archives of Occupational and Environmental Health (one of my favorite sources of light reading), suggests that heavy cell phone users do in fact raise their risk for tumors, especially on the side of the head they use most often.

The study looked at 2,200 cancer patients and the same number of healthy ones to see if any sort of connection could be drawn between specific cancers and heavy mobile phone usage. The answer was yes.
Kjell Mild, who led the study, said the figures meant that heavy users of mobile phones had a 240 percent increased risk of a malignant tumor on the side of the head the phone is used.
Now, before you reach behind your right ear and start probing yourself for lumps, there are a couple of things to remember. The first is that a 240 percent increase, while significant, still means that the chance of coming down with a tumor is rather low. The second thing is that "heavy usage" of cell phones is defined by the study as anything above 2,000 hours of use, which works out to one hour a day, every day, for almost six years. That's a lot of talking-but certainly not beyond the range of modern road warriors.

The study's authors suggest, as usual, that the best way to reduce your risk (short of ditching your phone altogether) is to use a hands-free system. One wonders, though, whether buying a headset and then shoving the phone in your pocket isn't likely to cause other, ahem, problems of equal severity.

It's also worth pointing out that research on the link between cancer and mobile phones is ambiguous. A recent British study found no such link only a few months ago, though a 2004 study came to the opposite conclusion. The Swedish team points out that their study is the largest done to date, though, so it may carry more authority than the rest.