How much radiation is emitted from an Iphone 5 vs what a person gets in background radiation?

How much radiation is emitted from an Iphone 5 vs what a person gets in background radiation?

Zero.

Phones do not emit any ionizing radiation at all- they only emit microwaves and radio waves. The radiation you are thinking of is ionizing radiation, of which phones do not emit any.

More, but it's less dangerous than ionizing radiation that you receive from the environment, it's just radio transmissions.

Most of the radiation you get from the environment comes from the radioactive potassium 40 in your food. You need potassium in your food to live, but because potassium 40 has a half life of about 1.5 billion years there hasn't been enough time since the Earth formed for most of it to have decayed away. This means that if you take a Geiger counter and look for the most radioactive thing in your house then it'll probably turn out to be you yourself because you're full of potassium 40.

The electromagnetic radiation from a mobile phone is measured as the Specific Absorption Rate (SAR). It depends how often the phone is transmitting and how close you are to a base-station (as the phone adjusts its power to what is needed).

In practice you get very little electromagnetic background radiation as the signals have travelled a long way and are very, very week (nanoWatts), when compared to a 2W mobile phone. There are legal limits to the SAR from a phone, < 1.6W/kg in US and < 2W/kg in Europe. This limit is far below any level thought to cause problems.

Apple state the SAR for an iPhone 5 is 0.972W/kg (head), http://www.apple.com/...one5,1/en/

http://www.fcc.gov/guides/specific-absorption-rate-sar-cell-phones-what-it-means-you