Cell phone users have something new to yak about: the biggest study ever of cell phones found no evidence whatever that even long-term use of the devices causes brain cancer.
The Danish study of more than 350,000 people showed that there was no difference in cancer rates between people who had used cell phones for more than a decade and people who hadn't.
The findings come less than six months after the International Agency for Research on Cancer called cell phones "possibly carcinogenic." That position grew out of a study of more than 14,000 people that showed a hint of a link between very heavy cell phone use and glioma, a rare but often deadly brain tumor.
In the new research, published online Thursday in the journal BMJ, researchers updated a previous study examining 358,403 cellphone users age 30 and over from 1990 to 2007. Cancer rates in people who used cell phones for about 10 years were similar to rates in people without a cell phone. Cell phone users were also no more likely to get a tumor in the part of the brain closest to where phones are usually held against the head.
Is this the last word on cell phone safety? Probably not.
"This is encouraging news, but it doesn't mean we're at the end of the road," said Hazel Nunn, head of Health Evidence and Information at Cancer Research U.K., which wasn't involved in the study.
Others disputed the study's findings. The advocacy group MobileWise, which believes cell phones pose a health risk, said the study wasn't long enough to gauge long-term risk, since brain tumors can take decades to form.
Nunn agreed that studies with longer-term data were needed and that there was little information on risk to children from cell phones.
The bottom line for now? Nunn said that except perhaps for limiting kids' use of cell phone, there was no need for cell phone users to change their habits based on the current evidence. As she put it, ""There are a lot more worrying things in the world than mobile phones."