There have been a lot of research as well as conspiracy theories by a lots of people on this topic, and I think currently with science researches we can say that using gadgets when it has to do with electromagnetic radiation is not harmful to humans but we should also understand that these gadgets and technologies also have other parts where they can be harmful to our health. Moreover, I believe that overtime, we might find out that some of these researches are funded by companies that want scientist to give the positive sides of the radioactive emissions their product release.
But for now, we can say that science haven't had any grounds to say that electromagnetic emissions are bad, so we can say that they have not effect in the short term and long term.