A new study is throwing another wrench into the cell phone-cancer debate.
Despite the International Agency for Research on Cancer (IARC)'s decision to classify cell phones as a possible carcinogen earlier this year, a study published in the American Journal of Epidemiology shows that cell phone use doesn't seem to increase the risk of a noncancerous brain tumor.
A study of nearly 3 million Danish adults showed that those who used a cell phone for more than 11 years were not more likely to develop a noncancerous brain tumor, called an acoustic neuroma or a vestibular schwannoma, than people who don't use a cell phone or only started using one recently. Even though acoustic neuromas are noncancerous, scientists say they are still important in determining whether there is a cancer risk from cell phones, according to Reuters.
And even more, tumors were not more frequent on the side of the head where the cell phone was most commonly used, nor did the tumor size have anything to do with the amount of cell phone use, according to the study.
But we're not out of the woods yet -- study researcher Dr. Joachim Schuz, of the World Health Organization's IARC (the same organization that classified cell phones as a possible carcinogen) said that even long-term cell phone users in the study haven't been using the devices long enough to completely rule out a cancer-cell phone link.
"As most cell phone users started their use only from the early 1990s onwards," Schuz told Reuters, "we have only up to 15 years of observation time of larger numbers of users -- which is perhaps too short to see an effect, if there is any."
Most studies in the past have not shown a link between cell phone use and cancer. One of the largest studies exploring the link, the 13-country INTERPHONE study, showed that cell phone use, frequency and call duration did not seem to affect the risk of developing a brain tumor.
And an article in the journal Environmental Health Perspectives published this year also showed that using a cell phone for 10 to 15 years didn't seem to affect brain cancer risk.
But as was the problem that Schuz acknowledged with his study, people haven't been using cell phones long enough to definitively know their effects after a long period of time, according to the American Cancer Society.
Still, your own judgment about the risks of cell phone use will come down to your personal prejudices. If you believe cell phones are guilty until proven innocent — and if you believe cell phone companies have something to hide — you'll be wary. If not, you'll likely be comforted by the studies that show little indication of harm. But what you'll almost certainly never get is an absolute answer from medical science.