Mobile phones put out very little power. There is no real evidence of anyone getting cancer or being harmed from mobile phones.
Having health problems from mobile phones is a lot of hype from people who are superstitious about everything, or like to be against the direction of society.
I, and my family have been in the electronics and communications business since the late 1920's. Today, all our family members are all using mobile phones, and had them since they first came out. None of us, including anyone we know of, ever had any problems from them. We mostly use mobile phones for all of our business and personal calls.
Before celliar phones were available, we had mobile phones in our cars. These phones put out a fair amount of power, and we never heard of anyone having any health problems from them.
The worse thing I ever had from a mobile phone, was a headache from too many people calling me when I am trying to eat a good lunch!
As for putting a mobile phone in a metal box, this would not do anything for
you anyways. This would only make access to the phone more difficult. The
antenna would have to stick out to be able to read the signal for the phone
to ring, or conduct phone calls.
When the phone is idling it must be able to transmit its acknowledgement
ID\'s to the repeater so that the system knows it can handle phone calls.
Mobile phones send a number of data packets for verification from time to
time, so that the system knows that it is present and that it can send and
receive calls.