As cell phones are growing more prevalent—an estimated 270 million Americans now have one—concerns about the health risks of the mobile devices are increasing as well. As Bryan Walsh reported for TIME earlier this year, the growing trend of cell phone use—or, cast in a different light, of holding tiny emitters of low-level radiation up to our heads several times a day—has scientists concerned, to say the least. Yet, according to preliminary research conducted by the Danish Cancer Society, as of yet there’s not enough evidence to declare the danger of our devotion to hand-held devices. An analysis of brain cancer cases throughout Scandinavia from 1974 to 2003 found that, trends in tumor rates have been consistent since before mobile phones came into widespread usage.
As the BBC reports, the analysis, which included some 16 million adults between the ages of 20 to 79, found that trends of brain tumor incidence were consistent in the last 10-15 years, when mobile phones came into popularity, with before cell phones first began to emerge. Brain cancers known as gliomas increased 0.5% per year among men, and 0.2% per year among women, and meningioma cancers increased by 0.8% per year among men, and 3.8% per year among women. (The sharper increase among women is largely attributable to the female population between the ages of 60 to 79, researchers say.)
These findings, which expand on previous research that analyzed trends through 1998, don’t rule out the possibility that cell phones may have harmful effects evident after more long-term use, researchers say. As Dr. Alison Ross, a senior science information offer at Cancer UK, told the BBC:
“Overall, the scientific evidence tells us that using mobile phones for less than 10 years does not increase the risk of cancer and this large study supports that conclusion… However, brain tumors often take a very long time to develop so we will need to look for any future changes in incidence rates to see if mobile phones could pose any longer-term risks.”
In other words, the jury is still out.