For many years now, we have known that cell phones are safe but to make sure that nothing has been missed and that we're as up to date as possible, the Food and Drug Administration (FDA) requested a series of new and in-depth studies on the effects a super-high dose of radio waves has on cells.

Their conclusion: devices that are commercially available are perfectly safe.

The studies didn’t set out to model reasonable usage of current cell phones but rather an extreme version of radio waves exposure. The tests were done on mice and rats as it could not be tested on humans. Most groups were exposed to nine hours of radio waves per day for two years. Some groups were exposed up to 18.5 hours per day for two years.

The studies haven’t found a single link to brain tumors but the researchers discovered some interesting tidbits of science nonetheless. There was a small increase of heart tumors in male rats but not in female rats. This tumor affects the nerve tissue around the heart, however, it is rare and it doesn’t translate directly to humans.

There was another finding that also doesn’t translate: rats exposed to phone-like radiation live on average longer than rats that live “cell phone free.” It is not clear if this is just chance or it could be that the radio waves reduce inflammation in rats and keep some rat diseases at bay. Some of the rats in the study did show DNA damage but there was no clear evidence that this was related to the radio waves.  

“Taken together, all of this research provides a more complete picture regarding radiofrequency energy exposure that has informed the FDA’s assessment of this important public health issue, and given us the confidence that the current safety limits for cell phone radiation remain acceptable for protecting the public health,” Dr Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, said in a statement.

The FDA concluded, once again, that taking into account all the available scientific evidence there is no link between cell phone usage and adverse effects on human health. There has not been an increase in the number of brain tumors since cell phones have become omnipresent in our lives. However, if you remain worried about cell phone usage, earphones and texting are good and safe alternatives to putting a cell to your ear.