In order to get better coverage almost all cellular towers are putting out more such radiation so you should take precautions around them if this bothers you.
The phone you can turn off or use a head set or head protector unit. Examples at http://www.lessemf.com/personal.html
I purchased an iphone 3gs a couple of years ago; about 1 and 1/2 years ago, I then upgraded to ios 5 on my phone to obtain some of the iphone 5 features on my phone. I am concerned about the SAR, though; does the ios 5 cause the radiation level to be what it would be on an iphone 5 or is it the level that would be for an iphone 3gs? Any help is appreciated, and thanks very much!