Nowadays, most of us are on our cellphones pretty much every waking minute—whether we’re taking calls, checking emails or scrolling social media—so it makes sense that we’d be concerned about the possible health effects of phone radiation. Specifically, mobile phones emit radiofrequency energy—or radio waves—which is a type of non-ionizing radiation, according to the National Cancer Institute. There’s concern that our bodies may absorb these waves and put us at an increased risk of cancer. But what have studies actually found on the matter? In short: It’s still a bit unclear.

In 2011, the World Health Organization declared cellphone radiation a possible carcinogen, although many studies have found no evidence that cellphone use increases cancer risk. A Danish study, for instance, compared cellphone billing information with brain tumor data from the Danish Cancer Registry and found no clear link. 

In 2016, however, the cellphone radiation question was put back in the spotlight when a study found that cellphone radiation caused tumors in rodents. The U.S. National Toxicology Program (NTP) study, led by researchers at the National Institute of Environmental Health Sciences, looked at the effects of long-term radiofrequency radiation exposure in rodents. Researchers exposed the rodents to heavy amounts of RF radiation for about nine hours a day for two years, explains the American Cancer Society. Some were even exposed to radiation in the womb. 

The result: 2% to 3% out of hundreds of male rats exposed to radiation developed brain tumors, compared with none of the control rats, according to a CNN report on the study. About 1% of female rats exposed to radiation developed tumors, but as the report points out, this could have been mere chance. 

Although more research is needed to establish whether cellphones really do increase our cancer risk, there’s no harm in taking preventative steps in case. For starters, limit the time you spend talking on your cellphone and use a landline instead. And if you do have to make long cellphone calls, consider using ear buds or speaker to keep the phone at a distance from your head. When you’re not using your phone, keep it out of your pocket and don’t sleep with it under your pillow, the Environmental Working Group (EWG) says.

In addition, avoid using the phone when you’re in an area with poor signal, as radiation levels are higher in this case. If you have children, limit their cellphone use and turn the phone to airplane mode if they are playing games on it.

Are you concerned about cellphone radiation? Share your thoughts below.