Studies have shown that there are harmful electromagnetic radiation that occur when our phones are operated. This radiations are said to be more when phones are used to make calls or when they are receiving messages.
I have even read from a message to me on whatsapp, that the radiation from mobile phone increase when the phone battery is very low.

In order to use our phones safely, I will first of all advice that we keep the usage of our phones to minimum.
Also;

1. Keep the handset if possible at least 2 to 7 inches away from your head , use earphones (hands free) or loudspeaker mode. It decreases the transmission of electro-magnetic radiation to the brain significantly.

2. When keeping your cell phones in pocket, keep the screen towards you so that antenna faces away from you. This will also protect the screen of your handset being broken.

3. Avoid cell phones usage in metal containers such as Elevators, Airplanes, Trains and any other type of metal container as it increases the Electro Magnetic Radiation. I think it is one of the reasons why there is provision for us to switch the phones to airplane mode.
Read More From: http://www.morelight.ml/2016/02/morelightml-7-must-read-cell-phone.html?m=1

good one @op...