Dear EarthTalk: What's the latest research on the question of whether cell phone use causes cancer?
--William Thigpen, via e-mail
Cell phones have only been in widespread use for a couple of decades, which is far too short a time for us to know conclusively whether or not using them could cause cancer. Research thus far appears to indicate that most of us have little if anything to worry about.
According to the federally funded National Cancer Institute, the low-frequency electromagnetic radiation that cell phones give off when we hold them up to our heads is "non-ionizing," meaning it cannot cause significant human tissue heating or body temperature increases that could lead to direct damage to cellular DNA. By contrast, X-rays consist of high-frequency ionizing electromagnetic radiation and can lead to the kind of cellular damage resulting in cancer. Nonetheless, some cell phone users and researchers still worry about our cell phone usage, given how much we now use them and how little we know about their potential long-term effects.
The reason the issue keeps coming up is that some initial studies in Europe, where cell phone usage caught on a decade before the U.S., showed links between some forms of tumors and heavy cell phone usage. As a result, researchers teamed up to do a more definitive study, called the "Interphone" study, across 13 countries between 2000 and 2004. The results, published in May 2010 in the peer-reviewed International Journal of Epidemiology, indicated no increased risk of developing two of the most common types of brain tumors, glioma and meningioma, from typical everyday cell phone usage. Study participants who reported spending the most time on their phones showed a slightly increased risk of developing gliomas, but researchers considered this finding inconclusive due to factors such as recall bias, whereby participants with brain tumors may have simply remembered past cell phone use differently from healthy respondents.
Researchers looking to get past the relatively...