Cellphone power levels are insignificant, even when held tightly against your head, 0.6 watt. Your skin absorbs more than that from the sun in 5 minutes. The old “brick” phones were quite a bit more powerful (3 watts) and *MAY* have posed a small hazard.
The problem with cellphones is the distraction they are while driving. Talking on a cellphone actually raises your likelihood of an accident above the risk in being legally drunk behind the wheel!
As I understand it the radiation spreads inversely with the cube of the distance. So the difference between 1 cm and 20 cm away is 8000:1
How can cell phones be more of a distraction than a backseat full of screaming fighting children? I find most of the distraction is just the normal distraction experienced when talking to someone while driving. Yes, there is a bit more manipulation involved, but I refer you back to the soccer mom with the soccer team in the back. We’ve all seen the example of driving down the road while simultaneously giving a spanking, hung halfway over the backseat.