Antennas are usually at the bottom of the phone, to keep them further from the head. The inverse square law helps out a lot to minimize the power you're subjected to. Also look into the difference between ionizing & non ionizing radiation. It's probably not as serious of an issue as a lot of people think. At least that's my understanding.
Discussion
Maybe I'm getting lazy or maybe I'm just starting to mature, but I am starting to not care about science and research as much. I know I still go on these little rants about health, pharma, and vaccines. But there is so much research out there that you can find to support whatever predetermined conclusions you have. So I'm at the point where I'm just going to assume that most things are bad for you but that the stress of worrying about those unhealthy things is equally harmful. So I try my best to avoid but also make sure to not let it completely disrupt my life. For example, if I'm alone I will just talk on the phone with speaker on. If I can't do that, then I'll grab headphones if they're available. But if they aren't I'll just put the phone up to my ear. That's how I feel about wired headphones. There isn't enough time in the world to review and debunk all the research on various health problems.