If you are concerned about cell phone radiation, then it is better to be as close as possible to a base station.
By far the primary radiation danger comes from the antenna next to your skull. It makes sense by physics, since that is
where the highest radiation intensity is because of the smallest distance. Nobody holds their head up against a base station antenna for hours.
Also think about it the other way around, why would a base station need to emit more radiofrequency power to transmit to your phone than your phone would need to transmit back?
The most important point however, is that phone handsets and base stations do automatic power adjustment: they use the minimum power necessary to talk to one another and they dynamically adjust it based on conditions.
So if you have a base station nearby and you have ‘five bars’, then your phone might emit a milliwatt. But if you have one or two bars if you’re further, then the phone could well emit a watt or two, right next to your brain.
By far that is the most critical parameter for human exposure to cell phone radiation.
So, if you are concerned about cell phone safety
1) use a wired (not wireless) headset and keep your phone antenna away from your skull
2) insist that base stations be put as close as reasonably possible
