The biggest study ever to look at the link between cell phones and cancer found no evidence of a connection between the two, according to a study published in the journal BMJ and reported by The Associated Press.

For the study, researchers examined data from more than 350,000 cell phone users older than 30. Researchers relied on both individuals’ own usage reports and cell phone records.

Scientists found that cancer rates in people who used cell phones for about 10 years were nearly the same as in people who didn’t. What’s more, findings also showed cell phone users were no more likely to get a tumor in the part of the brain closest to where people hold the devices against their head.

But researchers said they couldn’t rule out a small to moderate increase in cancer risk for subgroups of heavy cell phone users. In addition, while the study was large and comprehensive, some groups said the research had limitations. For example, more than 5 billion people use cell phones worldwide, making it difficult to compare cancer incidence between them and others who don’t use them. Another criticism was that the study lasted about 10 years, which might not be long enough to consider long-term cell phone user cancer risk.

Last year, while a large study found no clear connection between mobile phones and cancer, it did hint at a possible association between heavy cell phone use and a rare form of cancer. This led the International Agency for Research on cancer to classify cells as “possibly carcinogenic.”

What do scientists say? That adults should not change their cell phone habits based on current evidence.

While cell phones may not be linked to cancer risk, they may cause sleep loss. Click here to read more.